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Pyridine diamide complexes of early transition metals Guérin, Frédéric 1998

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PYRIDINE DIAMIDE COMPLEXES OF EARLY TRANSITION METALS: ACTIVATION OF SMALL ORGANIC MOLECULES by FREDERIC GUERIN B.Sc. Universite du Quebec a Chicoutimi, 1992 M.Sc. The University of Ottawa, 1994 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY in THE FACULTY OF GRADUATE STUDIES Department of Chemistry We accept this thesis as confonmng to the required standard THE UNIVERSITY OF BRITISH COLUMBIA November 1997 © Frederic Guerin, 1997 In presenting this thesis in partial fulfilment of the requirements for an advanced degree at the University of British Columbia, I agree that the Library shall make it freely available for reference and study. I further agree that permission for extensive copying of this thesis for scholarly purposes may be granted by the head of my department or by his or her representatives. It is understood that copying or publication of this thesis for financial gain shall not be allowed without my written permission. Department The University of British Columbia Vancouver, Canada Date I *T 0 0 i/\ If DE-6 (2/88) Abstract Titanium complexes bearing a pyridine-diamide ligand [2,6-(RNCH2)2NC5H3]2' (R = 2,6-diisopropylphenyl (BDPP); R = 2,6-dimethylphenyl (BDMP)) have been synthesized. The dichloride complexes [2,6-(RNCH2)2NC5H3]TiCl2 are prepared in high yield from {2,6-[(Me3Si)RNCH2J2NC5H3} and TiCl4 via the elimination of 2 equiv of ClSiMe3. Monoalkyl and bis(alkyl) complexes are prepared from [2,6-(RNCH2)2NC5H3]TiCl2 and various Grignard reagents. Reduction of the dichloride precursors (BDPP)TiCl2 and (BDMP)TiCl2 with excess 1% Na/Hg amalgam in the presence of >2 equiv of internal (PhC=CPh, EtC=CEt, PrC^CPr) or terminal (HC=CSiMe3, PhC^CH) alkynes yields metallacyclopentadiene derivatives in good yield No cyclotrimerization of alkyne is observed. Ligand activation is observed in certain cases for complexes bearing the BDMP ligand. In a similar way, the reaction of {2,6-[(Me3Si)RNCH2]2NC5H3} with TaCl5 yields the complex, w^r-(BDPP)TaCl„ and two equiv of ClSiMe3. The reduction of the trichloride complex with excess Na/Hg in the presence of alkynes yields the pseudo 5-coordinate Ta(III) derivatives, (BDPP)Ta(rr-RC=CR')Cl (R = R' = Pr, Et, Ph; R = Ph, R' = H). The 4-octyne compound reacts with LiC^CR to give the acetylide octyne derivatives (BDPP)Ta(r|2-PrC=CPr)(C=CR) (R = Ph, Bu, SiMe3, o-Me3SiC6H4). The phenylacetylide complex reacts with phenylacetylene to give the metallacyclic derivative (BDPP)Ta[(r|2-PhC=C)PrC=CPrHC=CPh]. Similarly, (BDPP)Ta(r|2-PrC=CPr)(C=CBu) and (BDPP)Ta(Ti2-PrCsCPr)(C=CSiMe3) react with HC^CBu and HC=CSiMe3 to give the expected metallacycles. (BDPP)Ta(ri2-PrC^CPr)(C<:Bu) reacts with HC^CPh to give (BDPP)Ta[(r|2-BuC=C)PrC=CPrHC=CPh] only, establishing that the starting acetylide is retained in the final product. Zirconium complexes bearing a pyridine-diamide ligand [2,6-(RNCH2)2-NC5H3]2' (R = 2,6-diisopropylphenyl (BDPP); R = 2,6-diethylphenyl (BDEP); R = 2,6-dimethylphenyl (BDMP); R = Pr (iPAP); R = Cy (CyAP); R = 2,4-dimethyl-3-pentylamine (LiAP); R = 'Bu (tBAP)) have been synthesized. The mixed amide complexes [2,6-(RNCH2>2-NC5H3]Zr(NMe2)2 are prepared in high yield from [2,6-(RHNCH2)2-NC5H3] and Zr(NMe2)4. The mixed amides react with excess ClSiMe3 to afford the dichlorides [2,6-(RNCH2)2-NC5H3]ZrCl2 in nearly quantitative yield. Dimethyl complexes are prepared from [2,6-(RNCH2)2-NC5H3]ZrCl2 and 2 equiv of MeMgBr. The frontier orbitals of a model of the fragment (BDEP)Zr are very similar the those of Cp2Zr. A similar protocol has been used to prepare [2,6-(RNCH2)2NC5H3]ZrX2 (X = NMe2, Cl, Me; R = 2-PhC6H4 (BPhP); 2-'PrC6H4 (BMPP); 2-'BuC6H4 (BMBP), 2-'Pr-6-MeC6H3 (MPPP)). NMR spectroscopy has been used to identify rotameric isomers derived from restricted rotation about the N-Cipso bond of the ligand. The aryl groups in (BPhP)ZrX2 complexes freely rotate at all temperatures (-8CTC to +80"C) while (BMPP)ZrX2 (X = NMe2, Cl, Me) derivatives adopt meso and rac rotamers at low temperatures. In contrast, (BMBP)ZrX2 and (MPPP)ZrX2 (X = NMe2, Cl, Me) compounds are locked at all temperatures. (BMBP)ZrCl2 is isolated as a single isomer, likely the meso rotamer, while (MPPP)ZrCl2 is a near statistical mixture of me so and rac isomers. iv Table of Contents Abstract 11 Table of Contents • • iv List of Tables  • »x List of Figures x List of Schemes xiv List of Abbreviations «xAcknowledgements xvi Introduction 2 1 Generalities2 Historical Background 5 3 Synthesis 6 3.1 Transmetallalion3.2 Elimination of amine hydrohalide 7 3.3 Elimination of alkane3.4 Transamination4 Characterization 8 4.1 Nuclear Magnetic Resonance Spectroscopy 8 5 Bonding Considerations 9 5.7 X-ray crystallography... 12 6 Chemical Properties of a M-N Bond 12 6.1 Insertion reactions 13 V 6.1.1 Insertion reactions of an alkene or alkyne 13 6.1.2 Insertion of RNCX (X = O, S, NR)6.1.3 Insertion of C02, CS2 and SO, 4 6.2 Reactions with protic compounds (protonolysis) 14 6.3 Miscellaneous reactions 15 6.3.1 Disproportionation reactions 15 6.3.2 Elimination reactions 6 7 Project Proposal • 16 8 References 18 Chapter One. Titanium Complexes -2 5 1 Introduction 25 1.1 Titanium amide complexes: history and recent advances 21.2 Alkyne cyclotrimerization mediated by transition metal complexes 29 2 Results and Discussion 31 2.1 Synthesis of aryl substituted pyridine diamines 31 2.2 Synthesis of alkyl substituted pyridine diamines 32 2.3 Synthesis of the titanium dichloride complexes 34 2.4 Synthesis of alkyl complexes 36 2.5 Reduction ofTiCL complexes: Metallacycle formation 46 2.5.1 Metallacyclopentadiene complexes derived from internal alkynes 46 2.5.2 Metallacyclopentadiene complexes derived from terminal alkynes 50 2.6 Reduction of titanium dichloride complexes: ligand C-H bond activation 56 2.7 Zwitterionic complex and reaction with olefins 61 3 Conclusions 63 4 Experimental Details 4 5 References 80 vi Chapter Two. Zirconium Complexes 1 Introduction 87 7.7 Generalities of zirconium amide complexes 87 1.2 Ziegler-Natta olefin polymerization2 Results and Discussion 93 2.1 2,6-disubstituted and 2,4-6-trisubstituted aryl diamido complexes 93 2.1.1 MO calculation 8 2.1.2 Reactivity of complex 5a 100 2.1.3 Other alkyl complexes 4 2.2 Ortho-substitutecl aryl diamido complexes ^25 2.3 Alkyl diamido complexes ]39 2.3.1 Other alkyl complexes 148 2.4 Polymerization ^2 2.4.1 Counterion effect 153 2.4.2 Ligand effect 5 2.4.3 Co-polymerization ^6 3 Conclusions 8 4 Experimental Details 159 5 References 190 Chapter Three. Tantalum Complexes 201 Introduction 201.1 Generalities 0 1.2 Alkyne polymerization 207 2 Results and Discussion 3 2.7 Pyridine diamide complexes of tantalum 20J 2.2 Reduction chemistry of pyridine diamide complexes of tantalum 205 vii 2.3 Metallocene vs pyridine diamide tantalum alkyne complexes 208 2.4 Crystal structure of(BDPP)Ta(rf-PrC=CPr)Cl 209 2.5 Reactivity of the rf-alkyne complexes 215 3 Conclusions 224 4 Experimental Details 5 5 References 238 Chapter Four. Group 3 Metal Complexes 242 1 Introduction 242 Results and Discussion 246 3 Conclusions 250 4 Experimental Details 1 5 References 253 Appendix ; 256 1 MO calculation results: 252 Crystallographic data for (BDMP)TiBr(CH2CMe:Ph) 266 3 Crystallographic data for (BDPP)Ti(C4a,P'-(SiMe3)H:) 275 4 Crystallographic data for (BDEP)ZrMe2 285 Crystallographic data for (BDPP'JZrOWBu) 294 6 Crystallographic data for (BDPP)Zr(CH2Ph)2 311 7 Crystallographic data for (BDPP)Zr(C4H6) 6 8 Crystallographic data for (CyAP)ZrMe, 324 9 Crystallographic data for (tBAP)ZrMe: 332 10 Crystallographic data for (tBAP)ZrMe(Me:Cl, 60:40) 340 11 Crystallographic data for (iPAP)ZrCfPr 347 12 Crystallographic data for (BDPP)TaCl(rr-oct-4-yne) 354 13 Crystallographic data for (BDPP)Ta(CPh=CHCFT=CPrC=CPh) 14 Design of polymerization reactor ix List of Tables Table 1. Metal-nitrogen bond distances in selected complexes 12 Table 1-1. Selected Bond Distances (A) and Angles (deg) for Sb'QHs 4Table 1- 2. Selected Bond Distances (A) and Angles (deg) for Complex 16b 51 Table 2-1. Selected Bond Distances (A) and Angles (deg) for 5b 96 Table 2- 2. Selected Bond Distances (A) and Angles (°) for Complex 25a 103 Table 2-3. Fluxional rtrri2-CH2Ph 108 Table 2- 4. Butadiene 'H NMR resonances of complex 13a-c 113 Table 2- 5. s-Cis / s-Trans ratio (%) for Cp2(R'CH=CR2CR3=CHR4) in CA, 116 Table 2- 6. Selected Bond Distances (A) and Angles (°) for complex 13a 118 Table 2- 7. Selected Bond Distances (A) and Angles O for Complex 5k 142 Table 2- 8. Selected Bond Distances (A) and Angles (°) for Complex 5m" 144 Table 2- 9. Selected Bond Distances (A) and Angles (°) for 5m' 146 Table 2- 10. Selected Bond Distances (A) and Angles (°) for complex 20j 152 Table 2-11. Polymerization results 153 Table 2- 12. Counter-ion effect 5 Table 2-13. Ligand effect 156 Table 2- 14. Ethylene/1-hexene co-polymerization 157 Table 3-1. Selected Bond Distances (A) and Angles (deg) for 4a 209 Table 3- 2. Selected Bond Distances (A) and Angles (deg) for 18a 218 X List of Figures Figure 1. Cationic Cp2MR* 2 Figure 2. Some bridged metallocene catalysts 3 Figure 3. Linked Cp-amide complexes 4 Figure 4. Linked bis(amide) and bis(alkoxide) complexes 4 Figure 5. Structural unit 5 Figure 6. Structure of Chlorophyll 6 Figure 7. Dimeric [Ti(NMe2)3]2 vs monomeric TirNCSiMe,)^ 9 Figure 8. Metal-amide orbital interactions 10 Figure 9. N3N ligand 11 Figure 10. Bonding of the N3N ligandFigure 11. Insertion products from PHNCO and Ti(NMe:)4 14 Figure 12. Pyridine diamide ligand 17 Figure 1- 1. Linked Cp-amide complex titanium 26 Figure 1- 2. [(Cy:N)2Ti(|i-CH2)]2 2Figure 1-3. Chelating diamide complexes 7 Figure 1- 4. Boron substituted amide ligand 8 Figure 1-5. Multipodal amide/amine ligands 2Figure 1- 6. (DIPP)2Ta(Ti6-C6Me6)Cl 30 Figure 1- 7. Restricted rotation of the aryl 5 Figure 1- 8. Mirror planes in complexes with Cs symmetry 38 Figure 1- 9. 'H NMR spectrum of complex 9b in C6D6 41 Figure 1-10. Top: Chem 3D™ drawing of the molecular structure of 8b«C6H6 (The benzene molecule is not shown.) Bottom: Chem 3D™ drawing of the core of 8b*C6H6. 43 Figure 1-11. Variable-temperature 'H NMR spectra of the ligand methylene (CH2N) region of compound 15a 49 xi Figure 1- 12. Top: Chem 3D™ representation of the molecular structure of 16b. Bottom: Chem 3D™ representation of the core of 16b 52 Figure 1- 13. 'H NMR spectrum of complex 18b 54 Figure 1- 14. 'H NMR spectrum of complex 20b 8 Figure 1- 15. 'H Homonuclear decoupling spectra for complex 20b 59 Figure 1- 16. 'H 13C HETCOR spectrum of complex 20b 60 Figure 2- 1. Chelating diamide complexes of Zr™ 87 Figure 2- 2. Cossee-Arlman ethylene polymerization mechanism 88 Figure 2- 3. Cationic CpjZrR 8Figure 2- 4. Some bridged metallocene complexes 89 Figure 2- 5. Isospecific catalysts, alternating handedness polymerization 90 Figure 2- 6. Waymouth's catalyst, bis(2-phenyl-indenyl)ZrCl2 9Figure 2- 7. Relationship between catalyst structure and stereoselectivity 91 Figure 2- 8. Linked Cp-amide complexes 92 Figure 2- 9. Non-Cp ligand systemsFigure 2- 10. Molecular structure of complex 5b deduced from X-ray crystallography 97 Figure 2-11. Geometry of complex 5b versus that of Cp2ZrMe2 98 Figure 2- 12. Molecular orbital diagram, (PyN2)M Vs Cp2M 9 Figure 2- 13. Orbital interactions between the amide ligands and the metal 100 Figure 2- 14. Metal-imido pseudo triple bond 101 Figure 2-15. Molecular structure of complex 25a from X-ray crystallographic analysis 102 Figure 2- 16. ri2-CH2Ph group 106 Figure 2- 17. Variable temperature 'H NMR spectra of complex 6a 107 Figure 2- 18. Molecular structure of complex 6a 109 Figure 2- 19. r|5-Cp vs T)6-PhCH2 structures 111 Figure 2- 20. Fluxional behavior of complex 7a 2 Figure 2- 21. Cp2Zr(benzyne) 112 Figure 2- 22. 'H NMR spectrum of complex 13a 114 Figure 2- 23. Coordination modes of butadiene 115 Figure 2- 24. Molecular structure of complex 13a from X-ray crystallography 117 Figure 2- 25. Bonding interactions for complexes 13a-c. 118 Figure 2- 26. 'H NOE spectra of complex 15a 123 Figure 2- 27. 'H NMR spectrum of complex 21a 124 Figure 2- 28. Asymmetric ligand 125 Figure 2- 29. Steric interactions in complex 2f 127 Figure 2- 30. Variable temperature 'H NMR spectra of complex 2g 128 Figure 2- 31. Meso and rac rotameric isomers of complex 2g 129 Figure 2- 32! Room temperature 'H NMR spectrum of complex 2h 130 Figure 2- 33. Structural deformation 132 Figure 2- 34. Variable temperature 'H NMR spectra of complex 5g 137 Figure 2- 35. Octahedral metathesis transition state 138 Figure 2- 36. Isomerization of the transition state 139 Figure 2- 37. Molecular structure of complex 5k from X-ray analysis 143 Figure 2- 38. Top, Molecular structure of complex 5m. Two asymmetric molecules were located in the unit cell; Bottom, core of the C2v-symmtetric molecule 145 Figure 2- 39. Variation of the Zr-N-C angle 146 Figure 2- 40. Molecular structure of complex 5m' from X-ray crystallography 147 Figure 2- 41. Comparison between the structure of 5m and 5m' 148 Figure 2- 42. Molecular structure of complex 20j from X-ray crystallography 151 Figure 2- 43. Steric protection 156 Figure 3- 1. 4 e' interaction of an alkyne with a metal 205 Figure 3- 2. Alkyl vs 2,6-substitutedphenyl ligands 207 xiii Figure 3- 3. exo and endo conformation of Cp2TaEt(MeCsCMe) 209 Figure 3- 4. Molecular structure of (BDPP)Ta(Ta(n:-Pr(>CPr)Cl (4a) deduced from single crystal X-ray analysis210 Figure 3- 5. 'H NMR spectrum of complex 9a 212 Figure 3- 6. 'H NMR spectrum of complex 6e 4 Figure 3- 7. (top) Molecular structure of complex 18a deduced from single crystal X-Ray analysis. 217 Figure 3- 8. endo and exo conformation 222 Figure 4- 1. Cationic CpJvlR 243 Figure 4- 2. Linked Cp-amide complex 244 Figure 4- 3. Size of the metal vs coordination geometry 249 List of Schemes Scheme 1. Steric effect on transamination reactions Scheme 2. Mechanism of Insertion Scheme 1-1. Mechanism of cyclotrimerization Scheme 1- 2. Alkylation of complexes 2a,b,d¥ Scheme 1-3. Proposed mechanism for the hydrogenation of complex 7a Scheme 1- 4. Proposed mechanism for the hydrogenation of complex 9b Scheme 1- 5. Preparation of Titanacyclopentadiene derivatives" Scheme 1- 6. Regiochemistry of the insertion Scheme 1-7. Proposed mechanisms for alkyne exchange Scheme 1- 8. Proposed mechanism for the formation of complex 20b Scheme 2-1. Proposed mechanism for ligand CH activation Scheme 2- 2. Alkylation of complexes 3a-b¥ Scheme 2- 3. Topomerization of s-cis-metallacyclopentene Scheme 2- 4. Reaction of complex 13a with unsaturated substrates Scheme 2- 5. Reaction of Cp2Zr(diene) with a-olefins Scheme 2- 6. Mechanism of ligand C-H activation Scheme 3- 1. Nb(IV) vs Ta(IV) amide complexes Scheme 3- 2. Polymerization of alkynes, insertion mechanism Scheme 3- 3. Polymerization of alkynes, alkylidene mechanism Scheme 3- 4. Alkylidene formation Scheme 3- 5. Reduction of the trichloride complexes 2ab,d,e Scheme 3- 6. Coordination/insertion mechanism Scheme 3- 7. Metallacyclopentadiene acetylide mechanism Scheme 4- 1. Cossee-Arlman Mechanism of Ziegler-Natta catalysis Scheme 4- 2. Roles of MAO XV List of Abbreviations A Angstrom MO molecular orbital Anal. Calcd analysis calculated NMR nuclear magnetic resonance atm atmosphere NOE nuclear Overhauser effect br broad OEt^ diethylether Bu butyl Ph phenyl COSY correlated spectroscopy ppm parts per million Cp cyclopentadiene Pr propyl Cy cyclohexyl Py pyridine deg degrees T3u terr-butyl DME 1,2-dimethoxyethane sbp square-base pyramid EI electron ionization tbp trigonal bipyramid equiv equivalent(s) THF tetrahydrofuran Et ethyl 'Pr /sopropyl HETCOR heteronuclear correlation ind indenyl IR infra-Red LLDPE linear low density polyethylene Lut lutidine M molar MAO methylaluminoxane Me methyl mL millilitre mmol millimole xvi Acknowledgements I would like to thank Prof. David H. McConville for his support and enthusiasm over the last four years. Thank you for keeping me "on track". I would also like to thank past and present group members. I would like to thank J. J. Vittal, N.C. Payne, G. P. Yap. and D. Stephan for solving the crystal structures presented in this manuscript. I also want to thank the support staff at UWO (Bruce Artwood and the mech shop guys) and UBC (Steve Rak, Peter Borda, mass spectrometry, electronic and mech shop staff). Finally, I would like to thank NSERC, Union Carbide Canada Inc., the University of Western Ontario and the University of British Columbia for their financial support. 1 "... I find that a great part of the information I have was acquired by looking up something and finding something else on the way... Franklin P. Adams 2 Introduction 1 Generalities In 1951 a compound of formula (C5H5)2Fe was reported and was subsequently shown to have a unique "sandwich" structure in which the metal lies between two planar cyclopentadienyl rings. As a result of the r|5 coordination, a cyclopentadienyl ligand acts like a 6-electron donor. The stabilizing effects of the two cyclopentadienyl ligands were rapidly realized. The organometallic chemistry of the transition metals has since been dominated by complexes bearing cyclopentadienyl ligands^. Cyclopentadienyl based complexes such as Cp2TiPh2, Cp2ZrPh2 or Cp2ZrCl22 have been used as homogeneous models for Ziegler-Natta olefin polymerization. It is believed that a cationic alkyl in the +4 oxidation state is the active catalytic species (Figure 1). These systems are very efficient catalysts for the polymerization of ethylene but do not polymerize a-olefins very efficiendy. Figure 1. Cationic CP2MR* The investigation of simple metallocene systems gave way to ingeniously designed bridged-metallocene complexes: for example, Figure 2a, rac-ethylenebis(r|5-tetrahydroindenyl)ZrCl23; Figure 2b, roc-dimethylsilylbis(T]5-indenyl)ZrMe24; and Figure 2c, isopropyl(r|5-Cp-l-ri5-fluorenyl)ZrCl25. Linking the two Cp ligands together results in a more References start on page 18 3 a b c Figure 2. Some bridged metallocene catalysts open metal centre and as a result these catalysts polymerize oc-olefins better than unbridged species. Amide ligands, like alkoxide ligands, are generally viewed as hard donors. This is an important difference when compared to a soft cyclopentadienyl donor. Moreover, amide ligands are formally 4 electron ligands, two less than a Cp group. These ligands can be viewed as electron deficient cyclopentadienyl equivalents. As a result, a transition metal surrounded by amide ligands is more electrophilic than when it is bound to an equal number of cyclopentadienyl ligands. In an attempt to create more electrophilic species, complexes where one of the cyclopentadienyl has been replaced were synthesized. Complexes that contain a linked cyclopentadienyl-amide ligand (e.g., Ti5-C5Me4SiMe2(NCMe3)MLI1, M = Ti, Zr, Hf6-8 or Sc9; L halide or alkyl) (Figure 3) were synthesized and used for the copolymerization of ethylene and oc-olefins (eq. 1). (1) References start on page 18 4 Cl Me2Si / Cl Cl Me2Si / N N f-Bu t-Bu M = Ti, Zr, Hf Figure 3. Linked Cp-amide complexes Unlike the metallocene-based catalysts, which do not incorporate oc-olefins very well, these complexes are very efficient at incorporating oc-olefins in the polymer chain. This is probably a result of the reduced steric crowding around the active catalytic centre and the increased electrophilicity of the metal. The next logical extension would be to replace both Cp ligands with amides or alkoxides. Recendy, complexes that contain a chelating diamide^ {Figure 4(1)} or bis(alkoxide)1 * {Figure 4(11)} functionality have been reported. M = Ti, Zr X = Cl, Me, CH2Ph (I) (II) Figure 4. Linked bis(amide) and bis(alkoxide) complexes References start on page 18 5 2 Historical Background A metal amide is defined as a compound which contains one or more M-NR2 (R = H, alkyl, aryl, e.g., 'NHMe, 'NMe2, "NPh2 or "N(SiMe3)2) moieties. These are generally molecular compounds having the general structural unit shown in Figure 5. However, some larger aggregates have been observed for small metals such as lithium. The first metal amide, zinc-bis(dimethylamide), was prepared in 1856 by Frankland^. The first transition metal dialkylamide complex was reported by Dermer and Femelius^ in 1935. They showed that the metathesis reaction of an excess of potassium diphenylamide and titanium tetrachloride formed tetrakis(diphenylamido)titanium. In 1959, Bradley and Thomas^ explored the use of lithium dialkylamides as reagents for the synthesis of early transition metal amides. Amide complexes for almost all the elements have since been synthesized. They are very common for early transition metals, however, they are rare for the later metals. Amide ligands can be found in homoleptic, i.e., M(NRR')n, or heteroleptic complexes, i.e., Me3SnNMe2 or Cp2Ti(NMe2)2. Finally, is its important to note that transition-metal amide complexes also have an important role in biological systems. Naturally occurring molecules such as chlorophyll (Figure 6) and vitamin B12 coenzyme (Cobalt based) contain M-N fragments. M N R Figure 5. Structural unit References start on page 18 6 C02phytyl Figure 6. Structure of Chlorophyll 3 Synthesis 3.1 Transmetallation The most common route to transition metal amide is via transmetallation (e.g., eq. 2). MCI„ + n LiNR2 • M(NR2)n + n LiCl (2) This synthetic procedure has since been employed to prepare a wide variety of transition metal amide complexes. This methodology generally affords the homoleptic amide complex in the same oxidation state. as the starting material. However, in some cases steric effects or disproportionation of the first formed homoleptic amide yields unexpected products (examples are in eq. 3*5, eq. 4^6,17 ancj eq 517) M0CI5 + 5 LiNMe2 Mo(NMe2)4 + LiCl + other products (3) TaCI5 + 5 LiNMe2 • Ta(NMe2)5 <4> References start on page 18 7 TaCI5 + 5 LiNEt2 • Ta(NEt2)3(NEt) ^> 3.2 Elimination of amine hydrohalide The elimination of [NR3H]+Cf has been used for many years as a synthetic approach to metal amide complexes (eq. 6). This methodology has been employed with the higher oxidation states of the early transition metals (for examples: Ti™ 18,19 \™20j Nbv21t Tav22, W™ 23, Wv 23> wVI 23-25). TiCI4 + 8 HNMe2 Ti(NMe2)4 + 4 [Me2NH2]+CI" <6> The main drawback with this method is the possible formation of a donor complex, for example, MoCl3(NHMe2)(NMe2)226. The use of sterically demanding groups on the nitrogen can prevent coordination of the amine donor. 3.3 Elimination of alkane The elimination of a simple alkane can also be used as a synthetic approach to metal-amide bonds. This route was used by Frankland to synthesis the first metal-amide, Zn(NR2),12(eq. 7). ZnEt2 + 2 HNR2 • Zn(NR2)2 + 2 C2H6 (7) This technique has one major advantage over the elimination of hydrohalide approach. There is no formation of amine which could potentially remain coordinated to the metal centre. Nevertheless, this method has not been widely employed due to the lack of stable metal alkyl complexes. 3.4 Transamination Transamination reactions are strongly dependent on steric factors. The steric requirements of the substituents on the incoming amine dictate the degree of substitution that is obtained as illustrated in Scheme 1^7 References start on page 18 8 excess HN Pr2 Ti(NMe2)3(N'Pr2) Ti(NMe2)4 3 HNPr2 Ti(NMe2)(NPr2)3 Scheme J. Steric effect on transamination reactions The more volatile amine is generally displaced. This procedure is particularly appealing if the eliminated amine is HNMe2. In this case, the desired complex is the only non-gaseous product. 4 Characterization 4.1 Nuclear Magnetic Resonance Spectroscopy ]H and I3C NMR spectroscopy have been used extensively to determine the presence and nature of transition metal amide complexes. The methyl groups in dimethylamine are observed at 2.18 ppm in the lH NMR (8, in C6D6). A shift to lower field strength is observed when the amide group is bound to a transition-metal. For example, the ]H NMR spectra of Ti(NMe2)428-31 and Zr(NMe2)4x4,29,30,32 show resonances at 3.04 ppm and 2.90 ppm (8, in C6D6), respectively. Heteroleptic complexes also exhibit a similar chemical shift variation by !H NMR spectroscopy. For example, Ti(NMe2)2Cl233,34 displays a signal at 3.14 ppm (8, in C6D6). A downfield shift of the methyl carbons is also observed by 13C{'H} NMR spectroscopy. Another important use of 'H NMR spectroscopy is in the elucidation of fluxional processes. Through variable temperature experiments, it is possible to observe the different species in equilibrium. One such example is the Tira dimeric complex [Ti(NMe2)3]235. The 'H NMR spectrum in D8-toluene shows a sharp singlet at room temperature. However, at -80°C, two distinct resonances 2.2 Hz apart are observed in approximately a 2:1 ratio. This is consistent References start on page 18 9 with a dimeric structure at low temperature (Figure 7). There are four distinct terminal NMe2 groups and two bridging moieties. At higher temperature, interconversion between the different sites is fast and a time averaged spectrum is obtained. Me2 Me2N/> vNMe2 ^N(SiMe3)2 ^Th- - - ™Ti^ (Me3Si)2N Ti^ Me2N N NMe2 N(SiMe3)2 Me2 Figure 7. Dimeric [Ti(NMe2)3]2 vs monomeric Ti[N(SiMe3)2]3 14N (/ = 1) NMR has not yet been used to any significant extent for the identification of metal amide complexes. This is in part due to the quadrupolar moment of 14N. 15N (/ = 1/2) has proven quite useful in determinig the diference between NH, NH2and N functionalities9-^-9^ 5 Bonding Considerations There are three possible metal-nitrogen interactions for an amido ligand. The first case involves only a o-bond between the metal and nitrogen. It this case the nitrogen has a pyramidal geometry and approximately sp3 hybridization (Figure 8 I). Figure 8 II illustrates 7t-bonding between the nitrogen atom and the metal centre. It is useful to compare the bonding interaction of a metal amide versus a metal alkyl. First, a c bond is formed by the overlap of the nitrogen sp2 orbital (or sp3 orbital in the case of a pyramidal nitrogen) with a suitable G-type orbital on the metal. Second, the lone pair of electrons on nitrogen can overlap with a suitable 7t-type metal orbital rendering the amide a four-electron donor (Figure 8 II). On the other hand, alkyl ligands can only donate two electrons. References start on page 18 10 M K 2-electrons (I) 4-electrons (II) 2-electrons to each metal (III) Figure 8. Metal-amide orbital interactions In the third type of interaction, the amide ligand behaves as a bridging moiety (Figure 8 III). It is generally possible to preclude such bonding by employing bulky substituents on nitrogen. For example, Ti(NMe2)3 is dimeric and its structure (Figure 7) shows two bridging and four terminal amide ligands^5,36 On the other hand, Ti[N(SiMe3)2]3 has a monomeric structure3"?. In some cases orbital availability may prevent metal-amide multiple bonding. For example, in the compound {(R3SiNCH2CH2)3N}ML38'39; R = Me, Ph, Cy, r-Bu; M = Ta, V (Figure 9), the geometry of the complex does not allow simultaneous n bonding between the three amide nitrogens and the metal. The result is a ligand centred non-bonding pair of electrons. This type of bonding can be viewed as a hybrid of the first two bonding possibilities. References start on page 18 11 Figure 9. /vyv ligand Consequently, the ligand can only be considered as a 12-electron donor and not 14 (three M-N double bonds {4 electrons each} and a M-N single bond {2 electrons}) as one might expect. N N N N N N 2 jr-bonds P 1 ligand centered non-bonding pair of electrons Figure 10. Bonding of the N3N ligand References start on page 18 12 5.1 X-ray crystallography The increased availability and reduced cost of single crystal X-ray diffraction analysis have made this an invaluable tool in the characterization of transition-metal complexes. This technique has allowed accurate measurement of the metal-nitrogen bond distances in many complexes (Table 1). Some arguments relating the degree of N->M rc-bonding to the bond distance have been proposed. Table 1. Metal-nitrogen bond distances in selected complexes Compounds M-N(amide) (Angstrom) Reference Cr[N(SiMe3)2],(NO) 1.790 40 TiCl3(NEt2) 1.852 41 Ni[N(SiMe3)2](PPh3)2 1.870 42 TiCl2[N(SiMe3)2] 1.89 43 Fe[N(SiMe3)2]3 1.918 44 Co[N(SiMe3)2](PPh3)2 1.924 42 W2(NMe2)6 1.97 45 Mo2(NMe2)6 1.98 46 Sc[N(SiMe3)2]3 2.049 47 Eu[N(SiMe3)2]3 2.259 47 Co[N(SiMe3)2]2(PPh3) 1.934 and 1.917 42 6 Chemical Properties of a M-N Bond The reactivity of a transition metal amide bond generally depends on its polarity and bond strength. The chemistry of metal amides can be compared with the isoelectronic alkyls, alkoxides and fluorides. They have much more in common with alkyls and alkoxides than fluorides. Bond References start on page 18 13 polarities (M^-X5-) and bond strengths increase in the sequence M-R < M-NRR' < M-OR < M-F. This follows the same trend as the electronegativity, C < N < O < F. 6.1 Insertion reactions Insertion reactions are one of the most common organometallic reactions. Two conditions must be met in order for an insertion to take place. The reagent must be susceptible to attack by a nucleophile and the M-NR2 bond must be polarized. The proposed concerted mechanism for this reaction is shown in Scheme 2. LNM—NRR' LNM- - NRR' LNM NRR' \ / V / A A \/ Scheme 2. Mechanism of Insertion 6.1.1 Insertion reactions of an alkene or alkyne As a result of the lack of polarity in the C-C multiple bond, simple internal olefins or alkynes do not react with a metal amide. However, strongly electron withdrawing groups facilitate the insertion. For example, Ti(NMe2)4 and Zr(NMe2)4 both react with MeOOCC^CCOOMe48 to form Ti[C(CONMe2)=C(COOMe)NMe2](NMe2)2OMe and Zr[C(CONMe2)=C(COOMe)NMe2]2(OMe)2, respectively. 6.1.2 Insertion of RNCX (X = O, S, NR) These insertion reactions of RNCX (X = O, S, NR) are normally carried out at room temperature. The yields are generally quantitative; for example, Ti(NMe2)4 reacts with PhNCO to form 1:2 (Figure 111) or 1:4 (Figure 1 III) complexes depending on the stoichiometry48. On the other hand, the zirconium and hafnium derivatives only afford the 1:4 complexes. The driving force for these reactions is provided by the strong metal-oxygen bond. References start on page 18 14 Me,N. Me2N' Ph N O (I) ^CNMe2 Ti: J2 Ph N O CNMe, J4 (II) Figure 11. Insertion products from PhNCO and Ti(NMe2)4 6.1.3 Insertion of C02, CS2 and S02 The insertion of C02 or CS2 into a LnM-NRR' bond generally yields the corresponding carbamate LnM-OCONRR' (e.g., eq. 828) or sulfamate LnM-SCSNRR' (e.g., eq. 935'49). However, in some cases, a change in the oxidation state of the metal together with redistribution of the ligands affords unexpected products (e.g., eq. lO3^49). Ti(NMe2)4 + C02 • Ti(OCONMe2)4 Ti(NMe2)4 + CS2 {Ti(NMe2)3}2 + CS2 (Ti»') Ti(SCSNMe2)4 Ti(SCSNMe2)4 (Tilv) (8) (9) (10) The reaction between a metal amide and S02 rarely affords the expected product. In most cases, the loss of thionyl or sulfuryl amide results in the formation of compounds having a M=0 or M-O-M bonds (eq. 1150,51) 7nis js undoubtedly the result of the high thermodynamic stability of a metal-oxygen bond and the reladvely weak S-0 bond. Ti(NMe2)2 + S02 • Ti(0)(OSONMe2)2 + OS(NMe2)2 (ii) 6.2 Reactions with protic compounds (protonolysis) The high susceptibility of transition metal amides to protic reagents has allowed the use of amide ligands as protecting groups for the synthesis of more complex molecules (eq. 12). The transamination reaction described earlier is considered a protonolysis reaction. References start on page 18 15 LnM-NR2 + HA • LnM-A + HNR2 (12) It this type of reaction, the metal amide, M-NR2, behaves as a base. The steric congestion around the nitrogen is of great importance in this type of reaction. The availability of a suitable orbital on the metal is also an important factor. A good example of the steric effect on the protonolysis of a metal amide bond is given with W(NMe2)6. The ease of alcoholysis follows the sequence MeOH > EtOH > PrOH > TiuOH, Me3CCH2OH, while Et3SiOH does not react at room temperature^. A wide variety of protic sources can be used: inorganic and organic acids, alcohols, terminal alkynes (eq. 13)^3 or even cyclopentadiene (eq. 14)54. +2 HOCPh Zr(Ti-C5H5)2(NMe2)2 • Zr(ri-C5H5)2(C=CPh)2 <13) - 2 HNMe2 Ti(NR2)4 + C5H6 • Ti(r,-C5H5)(NR2)3 + HNR2 (14) 6.3 Miscellaneous reactions 6.3.1 Disproportionation reactions The disproportionation of a metal amide involves a change in the formal oxidation state at the metal centre. It is a bimolecular internal redox reaction in which two products, oxidized and reduced derivatives of the original complex, are formed. The reaction generally occurs upon heating of a lower oxidation state metal amide. This type of reaction is common for early transition elements (eq. 16-^, eq. 16^8 anfj eq. \j55y {Ti(NMe2)2X}2 • Ti(NMe2)4 + 1/n {TiX2}n X = NMe2, NEt2, Nr^ or Cl 3 LiNEt2 VCI 3 V(NEt2)5 V(NEt2)4+ 1/n {V(NEt2)2}n <16> References start on page 18 16 3 LiNEt2 CrCI3 • Cr(NEt2); Cr(NEt2)4+ 1/n {Cr(NEt2)2}n <17> 6.3.2 Elimination reactions This type of reaction involves the elimination of a small stable molecule to afford a compound which may either contain a multiple M=N bond or the product of its oligomerization. The driving force for these reactions includes the facile removal of an amine or a trimethylhalogenosilane and the high standard free energies of the products. The elimination of trimethylchlorosilane has been reported for some transition metal complexes (eq. 18)^6,57 TiCI4 + N(SiMe3)3 TiCI3(N(SiMe3)2} + CISiMe3 (18) 1/n{TiCI2N(SiMe3)}n + CISiMe3 7 Project Proposal The bent metallocene fragment is one of the most intensely studied moieties in early-transition-metal chemistry. As a result, complexes that contain one or even no cyclopentadienyl groups have received increasing attention. Polyfunctional amide38'58-70 ancj alkoxide^'^9 ligands have been studied in this context. These ligands can be viewed as electron deficient cyclopentadienyl equivalents. It was demonstrated that enhanced kinetic protection of the metal centre can be obtained by linking the amide donors8^"83. Moreover, the introduction of a donor functionality in the ligand can be used to modify the electronic properties of the metal centre and to provide rigidity to the ligand framework84"8'?. For example, the amide donors can be incorporated into a pyridine References start on page 18 17 backbone that significantly reduces the flexibility of the ligand, enforcing a meridional Figure 12. Pyridine diamide ligand With this in mind, we decided to vary the size of the R-groups attached to nitrogen, thus altering the steric environment about the metal. The synthesis and characterization of some early transition metal complexes of this pyridine diamide ligand are described in the proceeding chapters89"9^. coordination (Figure 12)88. .R References start on page 18 18 8 References (1) Bochmann, M, Comprehensive Organometallic Chemistry II; Bochmann, M., Ed.; Elsevier Science Ltd.: New York, 1995; Vol. 4. (2) Ewen, J. A. J. Am. Chem. Soc. 1984,106, 6355. (3) Kaminsky, W.; Kulper, K.; Brintzinger, H. H.; Wild, F. R. W. P. Angew. Chem., Int. Ed. Engl. 1985, 24, 507. (4) Bochmann, A.; Lancaster, S. J. Angew. Chem., Int. Ed. Engl. 1994, 33, 1634. (5) Ewan, J. A.; Jones, R. L.; Razavi, A. J. Am, Chem. Soc. 1988,110, 6255. (6) Canich, J. A. ; Canich, J. A., Ed., European Patent Application EP-420-436-A1; Vol. April 4, 1991. (7) Canich, J. A.; Turner, H. W. ; Canich, J. A.; Turner, H. W., Ed., W. PCT Int. Appl. WO 92/12162; Vol. fding date December 26, 1991. (8) Stevens, J. C; Timmers, F. I; Wilson, D. R.; Schmidt, G. F.; Nickias, P. N.; Rosen, R. K.; Knight, G. W.; Lai, S. Y. ; Stevens, J. C; Timmers, F. J.; Wilson, D. R.; Schmidt, G. F.; Nickias, P. N.; Rosen, R. K.; Knight, G. W.; Lai, S. Y., Ed., European Patent Application EP-416-815-A2; Vol. March 13, 1991. (9) Shapiro, P. J.; Bunel, E.; Schaefer, W. P.; Bercaw, J. E. Organometallics 1990, 9, 867. (10) Cloke, F. G. N.; Geldbach, T. J.; Hitchcock, P. B.; Love, J. B. J. Organomet. Chem. 1996, 506, 343. (11) van der Linden, A.; Schaverien, C. J.; Meijboom, N.; Ganter, C; Orpen, A. G. J. Am. Chem. Soc. 1995,117, 3008. (12) Frankland, E. Proc. Roy. Soc. 1856-7, 8, 502. (13) Dermer, D. C; Fernelius, W. C. Z. Anorg. Chem. 1935, 221, 83. References start on page 18 19 (14) Bradley, D. C; Thomas, I. M. Chemical Society London. Proceedings 1959, 225. (15) Bradley, D. C; Chisholm, M. H. J. Chem. Soc. (A) 1971, 2741. (16) Burger, H. Monatsh. 1964, 95, 671. (17) Bradley, D. C; Gitlitz, M. H. J. Chem. Soc. (A) 1969, 1894. (18) Drake, J. E.; Fowles, G. W. A. J. Chem. Soc. 1960, 1498. (19) Cowdell, R. T.; Fowles, G. W. A. J. Chem. Soc. 1960, 2522. (20) Fowles, G. W. A.; Pleass, C. M. J. Chem. Soc. 1957, 1674. (21) Fowles, G. W. A.; Pleass, C. M. J. Chem. Soc. 1957, 2078. (22) Fuggle, J. C; Sharp, D. W. A.; Winfield, J. M. J. Chem. Soc, Dalton Trans. 1972, 1766. (23) Brisdon, B. J.; Fowles, G. W. A.; Osborne, B. P. J. Chem. Soc. 1962, 1330. (24) Majid, A.; McLean, R. R.; Sharp, D. W. A.; Winfield, J. M. Z. Anorg. Chem. 1971, 385, 65. (25) Majid, A.; Sharp, D. W. A.; Winfield, J. M.; Hanby, I. J. Chem. Soc, Dalton Trans. 1973, 1876. (26) Edwards, D. A.; Fowles, G. W. A. J. Chem. Soc. 1961, 24. (27) Bradley, D. C; Thomas, I. M. J. Chem. Soc 1960, 3857. (28) Alyea, E. C; Bradley, D. C; Lappert, M. F.; Sanger, A. R. J. Chem. Soc, Chem. Commun. 1969, 1064. (29) Bradley, D. C; Gitlitz, M. H. J. Chem. Soc. (A) 1969, 980. (30) Gibbins, S. G.; Lappert, M. F.; Pedley, J. B.; Sharp, G. J. J. Chem. Soc, Dalton Trans. 1975, 72. (31) Burger, H.; Kluess, C; Neese, H.-J. Z. Anorg. Chem. 1971, 381, 198. References start on page 18 20 (32) Bradley, D. C; Thomas, I. M. J. Chem. Soc. 1960, 3857. (33) Burger, H.; Neese, H.-J. Z Anorg. Chem. 1969, 365, 243. (34) Benzing, E. P.; Kornicker, W. A. Chem. Ber. 1961, 94, 2263. (35) Lappert, M. F.; Sanger, A. R. J. Chem. Soc. (A) 1971, 874. (36) Alyea, E. C; Bradley, D. C; Copperthwaite, R. G. J. Chem. Soc, Dalton Trans. 1972, 1580. (37) Bradley, D. C; Copperthwaite, R. G. J. Chem. Soc, Chem. Commun. 1971, 764. (38) Cummins, C. C; Schrock, R. R.; Davis, W. M. Organometallics 1992,11, 1452. (39) Cummins, C. C; Lee, J.; Schrock, R. R. Angew. Chem,, Int. Ed. Engl. 1992, 31, 1501. (40) Bradley, D. C; Hursthouse, M. B.; Newing, C. W.; Welch, A. J. J. Chem. Soc, Chem. Commun. 1972, 567. (41) Fayos, J.; Mootz, D. Z. Anorg. Chem. 1971, 380, 196. (42) Bradley, D. C; Hursthouse, M. B.; Smallwood, R. J.; Welch, A. J. J. Chem. Soc, Chem. Commun. 1972, 872. (43) Alcock, N. M.; Pierce-Butler, M.; Willey, G. R. J. Chem. Soc, Chem. Commun. 1974, 627. (44) Bradley, D. C; Hursthouse, M. B.; Rodesiler, P. F. J. Chem. Soc, Chem. Commun. 1969, 14. (45) Chisholm, M. H.; Exxtine, M. W.; Cotton, F. A.; Stults, B. R. J. Am. Chem. Soc. 1976, 98, 4477. (46) Chisholm, M. H.; Cotton, F. A.; Frenz, B. A.; Shive, L. J. Chem. Soc, Chem. Commun. 1974, 480. (47) Bradley, D. C; Ghotra, J. S.; Hart, F. A. J. Chem, Soc, Dalton Trans. 1973, 1021. References start on page 18 21 (48) Chandra, G.; Jenkins, A. D.; Lappert, M. F.; Sricastava, R. C. J. Chem. Soc (A) 1970, 2550. (49) Lappert, M. F.; Sanger, A. R. J. Chem. Soc. (A) 1971, 1314. (50) Noth, H.; Schweizer, P. Chem. Ber. 1964, 97, 1464. (51) Chandra, G.; George, T. A.; Lappert, M. F. J. Chem. Soc. (A) 1969, 2565. (52) Bradley, D. C; Chisholm, M. H.; Extine, M. W.; Stager, M. E. Inorg. Chem, 1977, 16, 1794. (53) Jenkins, A. D.; Lappert, M. F.; Srivastava, R. C. J. Organomet. Chem. 1970, 23, 165. (54) Anderson, H. H. J. Am, Chem. Soc. 1953, 75, 1576. (55) Basi, J. S.; Bradley, D. C; Chisholm, M. H. J. Chem, Soc. (A) 1971, 1433. (56) Alcock, N. W.; Pierce-Butler, M.; Willey, G. R. J. Chem. Soc, Dalton Trans. 1976, 707. (57) Akiyama, M.; Chisholm, M. H.; Cotton, F. A.; Extine, M. W.; Murillo, C. A. Inorg. Chem. 1977, 16, 2407. (58) Aoyagi, K.; Gantzel, P. K.; Kalai, K.; Tilley, T. D. Organometallics 1996,15, 923. (59) Bemo, P.; Minhas, R.; Hao, S.; Gambarotta, S. Organometallics 1994, 13, 1052. (60) Cai, S.; Schrock, R. R. Inorg. Chem. 1991, 30, 4106. (61) Warren, T. H.; Schrock, R. R.; Davis, W. M. Organometallics 1996,15, 562. (62) torn Dieck, H.; Rieger, H. J.; Fendesak, G. Inorg. Chim. Acta 1990, 777, 191. (63) Planalp, R. P.; Andersen, R. A.; Zalkin, A. Organometallics 1983, 2, 16. (64) Okuda, J. Chem. Ber. 1990,123, 1649. (65) Dick, D. G.; Duchateau, R.; Edema, J. J. H.; Gamborotta, S. Inorg. Chem. 1993, 32, 1959. References start on page 18 22 (66) Burger, H.; Betersdorf, D. Z Anorg. Allg. Chem. 1979, 459, 111. (67) Bradley, D. C; Chudzynska, H.; Backer-Dirks, J. D. J.; Hursthouse, M. B.; Ibrahim, A. A.; Motevalli, M.; Sullivan, A. C. Polyhedron 1990, 9, 1423. (68) Bradley, D. C. Inorg. Syn. 1978, 75, 112. (69) Tsuie, B.; Swenson, D. C; Jordan, R. F. Organometallics 1997,16, 1392. (70) Male, N. A. H.; Thornton-Pett, M.; Bochmann, M. J. Chem. Soc, Dalton Trans. 1997, 2487. (71) Jones, R. A.; Hefner, J. G.; Wright, T. C. Polyhedron 1984, 3, 1124. (72) Balaich, G. L.; Hill, J. E.; Waratuke, S. A.; Fanwick, P. E.; Rothwell, I. P. Organometallics 1995,14, 656 and references therein. (73) Lubben, T. V.; Wolczanski, P. T.; Van Duyne, G. D. Organometallics 1984, 3, 977. (74) Duff, A. W.; Kamarudin, R. A.; Lappert, M. F.; Norton, R. J. J. Chem. Soc, Dalton Trans. 1986, 489. (75) Floriani, C; Corazza, F.; Lesueur, W.; Chiesi-Villa, A.; Guestini, C. Angew. Chem., Int. Ed. Engl. 1989, 28, 66. (76) Durfee, L. D.; Hill, J. E.; Fanwick, P. E.; Rothwell, I. P. Organometallics 1990, 9, 75. (77) Berg, J. M.; Clark, D. L.; Huffman, J. C; Morris, D. E.; Sattelberger, A. P.; Streib, W. E.; Van Der Sluys, W. G.; Watkin, J. G. J. Am, Chem. Soc. 1992,114, 10811. (78) McLain, S. J.; Ford, T. M.; Drysdale, N. E. 1992, 463-464. (79) McLain, S. J.; Drysdale, N. E. Polymer Preprints 1992, 33, 463. (80) Brauer, D. J.; Burger, H.; Weigel, K. J. Organomet. Chem. 1978, 750, 215. (81) Burger, H.; Dammgen, U. Z Anorg. Chem. 1977, 429, 173. References start on page 18 23 (82) Burger, H.; Weigel, K. J. Organomet. Chem. 1977,124, 279. (83) Bradley, D. C; Torrihle, E. G. Can. J. Chem. 1962, 41, 134. (84) Fuhrmann, H.; Bernner, S.; Arndt, P.; Kempe, R. Inorg. Chem. 1996, 35, 6742. (85) Friedrich, S.; Gade, L. H.; Edwards, A. J.; McPartlin, M. J. Chem. Soc, Dalton Trans. 1993, 2861. (86) Schubart, M.; O'Dwyer, L.; Gade, L. H.; Li, W.-S.; McPartlin, M. Inorg. Chem. 1994, 33, 3893. (87) Baumann, R.; Davis, W. M.; Schrock, R. R. J. Am. Chem, Soc. 1997,119, 3830. (88) Cai, S.; Schrock, R. R. Inorg. Chem, 1991, 30, 4105. (89) Guenn, F.; McConville, D. H.; Vittal, J. Organometallics 1995,14, 3154. (90) Guerin, F.; McConville, D. H.; Vittal, J. J. Organometallics 1996,15, 5586. (91) Guenn, F.; McConville, D. H.; Payne, N. C. Organometallics 1996, 75, 5085. (92) Gudrin, F.; McConville, D. H.; Vittal, J. J.; Yap, G. P. Organometallics 1997, Submited for publication. (93) Banaszak Holl, M. M.; Wolczanski, P. T. J. Am. Chem. Soc. 1990,112, 7989. (94) Banaszak Holl, M. M.; Wolczanski, P. T. J. Am. Cham. Soc. 1992,114, 3854. (95) Banaszak Holl, M. M.; Wolczanski, P. T.; Proserpio, D.; Bielecki, A.; Zax, D. B. Chem. Mater., 1996, 5, 2468. References start on page 18 24 "... As a general rule, the shorter the interval that separates us from our planned objective the longer it seems to us, because we apply to it a more minute scale of measurement, or simply because it occurs to us to measure it..." Marcel Proust 25 Chapter One. Titanium Complexes 1 Introduction 1.1 Titanium amide complexes: history and recent advances Of all the transition elements, homoleptic and heteroleptic titanium amide complexes have been studied in the greatest detail I"3. Many amide complexes of Tim and Ti™ are known but there are few examples of Ti1 or Tin. The only Ti1 compound that has been reported is TiNMe24. Low oxidation state complexes are generally obtained by disproportionation of Tira or Ti™ complexes. For example, the Tim complexes [Ti(NMe2)3]2 disproportionate to the Ti™ complex Ti(NMe2)4 and the Ti" complexes [Ti(NMe2)2]m5>6. Similar reactivity has been observed for the halide complexes^-8. The structures of the low valent titanium amide complexes are polymeric with bridging NR2 groups. Many Tiin amide complexes have been synthesized. Homoleptic complexes of the general formula Ti(NR2)3 are known for NR2 = NMe25,6,9 NEt25,6,95 NPh^O, NtSiMe^1 i'13 or cyclopropamide^. Heteroleptic amide complexes Ti(NR2)x(NR'2)3.x (e.g., Ti(NMe2)2(NEt2)^) and TiLx(NR2)3.x (where L = r|-C5H5 or alkyl and R = alkyl) (e.g., Cp2Ti(NMe2) or CpTi(NMe2)2 (NEt2)5,6,9) are also known. Recently, Tim and Ti™ alkyl complexes stabilized by a linked cyclopentadienyl-amide ligand (Figure 1- 1) have been synthesized and their use for the polymerization of olefins demonstrated I4" 16 References start on page 80 26 Figure 1-1. Linked Cp-amide complex titanium Of the four oxidation states, Ti™ forms the most numerous amide complexes. Homoleptic complexes of formula Ti(NR2)4 are known for NMe2,17"19 NEt,17"21, NPr217, N'Pr222, NBu2l7, NPh223 etc. Heteroleptic compounds have also been prepared. For example, the mixed amide complexes (e.g., Ti(NMe2)3(N'Pr2)24), amide-alkyl complexes (e.g., Cp2Ti(NMe2)225'26, (PhCH2)2Ti(NMe2)227 or Me2Ti(NMe2)227) or amide-halide complexes (e.g., Cl3Ti(NMe2)28, Cl2Ti(NMe2)228>29, ClTi(NMe2)329) have been reported. It has been shown that the bulky dicyclohexylamide ligand can stabilize a highly reactive Ti™ methylene complex (Figure 1- 2)30. in comparison, the cyclopentadienyl complexes Cy^ / cy N N H2 N ,. / Ti \ N c/ Xcv H Figure 1- 2. [(Cy2N)2Ti(p.-CH2)]2 References start on page 80 27 [Cp2Ti(|i-CH2)]23l and Cp2Ti(=CH2)PMe332 have only been characterized on the basis of spectroscopic data. Polyfunctional amide complexes of Tira and Ti™ have also been synthesized. Many different linking group have been designed taking advantage of the chelate effect to offer enhanced stereorigidity of the metal centre (for example: three-atom bridge, Figure 1- 3(1)33 and (2) (R = Me, 'Pr, SiMe3)34; two-atom bridge, Figure 1- 3(3)35,36; single-atom bridge, Figure 1- 3(4)37). Me^ N—SiMe2 (PhCH2)2Ti( ) N—SiMe2 Me 0) R ( /i(NEt2)2 ^ N R (2) Me I fBu I i /N^SiMe2 Br2Ti; 1 \-SiMe2 i N\ C\2T\ /SiMe2 N 1 [lie (3) 'Bu (4) Figure 1- 3. Chelating diamide complexes Recendy, attempts to alter the electrophilicity of the metal centre by changing the electronic properties of the diamide ligands have been reported. For example, the use of a strongly n-accepting boryl group on the amide has been reported (Figure 1- 4)38. The electron accepting properties of the boron reduce the ability of the nitrogen to donate 7t-electron density to the metal centre. As a result, the metal centre should be more electrophilic than the corresponding alkyl or arylamide complexes. References start on page 80 28 Ar\ ^Ar •N U ,B, Ar" "Ar Ar = 2,4,6-trimethylphenyl Figure 1- 4. Boron substituted amide ligand The introduction of a donor functionality in amide ligands has been used to modify the electronic properties of the metal centre and the rigidity of the complex. Following this approach, bipodal mono(amide) {Figure 1- 5(1)39}, tripodal di(amide) {Figure 1- 5(2)40} amj tetrapodal tri(amide) {Figure 1- 5(3)41} complexes of titanium(IV) have been reported. Me3Si N; ;N-Me2NHi»-Ti— NMe2 Cl Nci ci—TI; a N\ SiMe3 SiMe, ,N—-M ««N Me* •M-I Cl Me Me 0) (2) (3) Figure 1- 5. Multipodal amide/amine ligands References start on page 80 29 1.2 Alkyne cyclotrimerization mediated by transition metal complexes Catalytic cyclotrimerization of alkynes leading to substituted arenes can be accomplished with a variety of transition metal complexes such as Ti^2,435 Zr^-4,45^ Nb46-49? Ta47-52? Rn53,54^ p£j55,56i Co^7 and Ir58 This type of reaction has been used for the synthesis of organic molecules. For example, rhodium assisted cyclotrimerization has been used in the synthesis of C-arylglycoside (an antitumor agent)53. The mechanism of cyclotrimerization of alkynes by transition metal complexes has been debated extensively in the literature47,59-75 jhe cyclization of alkynes most often proceeds by an intermediate metallacyclopentadiene complex (A, Scheme 1- 1). The point of contention involves the intermediates involved in the reaction of a metallacyclopentadiene with 1 equiv of alkyne to generate the uncomplexed arene product. Two mechanisms have been proposed for the addition of a third alkyne. In the first mechanism the addition proceeds through a metallacycloheptatriene complex (B-path 1, Scheme 1- 1) and the two new carbon-carbon bonds are formed in a stepwise fashion. The second mechanism involves the concerted formation of the two carbon-carbon bonds via the formation of the Diels-Alder "7-metallanorbornadiene" adduct (C-path 2, Scheme 1-1). 1 M +2 B M M *6 2 C Scheme 1- 1. Mechanism of cyclotrimerization References start on page 80 30 Recent work by Wigley and co-workers has shed some hght on the mechanism operative in the alkyne cyclotrimerization reactions using early transition metal complexes^2'7*). The two-electron reduction of (DIPP^TaCl^OE^) (DIPP = 2,6-diisopropylphenoxide) in the presence of 2-butyne affords (DIPP)2Ta(r|6-C6Me6)Cl. The molecular structure of (DIPP)2Ta(r|6-C6Me6)Cl (Figure 1- 6) shows striking resemblance to the proposed Diels-Alder intermediate (C, Scheme 1-1). Related studies on an iridacyclopentadiene complex also favor a concerted pathway77. Cyclization reactions are highly dependent on the steric and electronic properties of the ancillary ligands 78-81 Under similar conditions, the more sterically hindered complex, (DIPP)3TaCl2(OEt,) (DIPP = 2,6-diisopropylphenoxide), does not lead to the formation of hexaethylbenzene, and only the metallacyclopentadiene complex (DIPP)3Ta(C4Et4)82,83 1S obtained. In contrast, various metallocene-based metallacyclopentadiene complexes undergo facile alkyne insertion to yield the corresponding metallacycloheptatriene84 or metallacyclononatetraenes8^. There are however no reports of catalytic oligomerization or polymerization of alkynes using metallocene complexes. OAr Figure 1- 6. (DlPP)2Ta(rf-C6Me6)Cl References start on page 80 31 2 Results and Discussion 2.1 Synthesis of aryl substituted pyridine diamines 2,6-Bis(bromomethyl)pyridine86 was treated with two equivalents of LiNRH to yield the diamine compounds {(BDPP)H2 (la), R = 2,6 diisopropylphenyl; (BDMP)H2 (lb), R = 2,6 dimethylphenyl} (eq. 1) in 50-80% yield. R / Surprisingly, no reaction occurs between the diamine 2,6-(RHNCH2)2NC5H3 and Ti(NMe2)4 or Ti(NMe2)2Cl2, even at elevated temperatures (110 °C). Moreover, attempts to deprotonate the diamine to form the diamide derivatives were unsuccessful. Deprotonation using n-BuLi only yielded strongly coloured decomposition products. KH did not react with (BDPP)H2 or (BDMP)H2. The pyridine nitrogen atom stabilizes negative charges at the benzylic positions, thus abstraction of the benzylic protons is favoured and decomposition occurs. An alternative route to diamide complexes of titanium was necessary. The addition of 2 equivalents of LiNR(SiMe3) to a DME solution of 2,6-bis(bromomethyl)pyridine at -30 °C affords the white crystalline silylated diamines 2,6-{(Me3Si)RNCH2}2NC5H3 (2a,b) in moderate yield (eq. 2). References start on page 80 32 R / 2.2 Synthesis of alkyl substituted pyridine diamines The reaction of 2 equivalents of LiNR(SiMe3) (R = Cy, Pr or 'Bu)} with 2,6-bis(bromomethyl)pyridine does not afford the expected silylated diamines. A white insoluble polymeric material is isolated after workup. This is probably a result of the lack of steric protection at the nitrogen centre. Nucleophilic attack on a CH2Br functionality by a newly formed CH2NR(SiMe3) group is a possible reaction pathway (eq. 3) for the formation of polymer. - BrSiMe3 References start on page 80 33 Similarly, the reaction of 2 equivalents of LiNHR (R = Cy, 'Pr or T3u) with 2,6-bis(bromomethyl)pyridine does not yield the expected diamines. The proposed reaction mechanism is similar to the one above and involves the attack on a CH2Br group by a CH2NRH group to afford the ammonium salt CH2NHR+Br" (eq. 4). The addition of solid 2,6-bis(bromomethyl)pyridine to a large excess of H2NR (R = Cy, 'Pr or 'Bu) in hexanes at room temperature affords the oily diamines 2,6-(HRNCH2)2NC5H3 {(CyAP)H2 (lc) R = Cy; (iPAP)H2 (Id) R = 'Pr; (tBAP)H2 (le) R= 'Bu} in quantitative yield after workup (eq. 5). Compounds lc,d,e can be prepared on a scale of 10-15 g and can be purified by distillation under full vacuum to afford colourless oils. R / (c) R = cyclohexyl \ (d) R = isopropyl R (e) R = tert-butyl 1 c-e The addition of 2 equivalents of halotrimethylsilane to a diethyl ether solution of lc-e at ambient temperature results in the rapid formation of a white precipitate. The complexed hydrogen halide formed in the reaction can then be removed by quenching with an excess of Et3N (eq. 6). The silylated compounds 2c-e can be prepared on a large scale in high yield using this synthetic method. References start on page 80 34 \ (c) R = cyclohexyl \ R (d) R = isopropyl R (e) R = fert-butyl 2c-e 2.3 Synthesis of the titanium dichloride complexes The silylated diamines 2a,b react cleanly with TiCl4 to give 2 equivalents of ClSiMe3 (confirmed by 'H NMR spectroscopy) and the red dichloride complexes (3a,b) in >85% yield (eq. 7). R (b) R = 2,6-Me2-C6H3 (c) R = cyclohexyl (d) R = isopropyl Compounds 2c,d also react with TiCl4 to give the red dichloride complexes (3c,d) in 50% and 72% yield, respectively. However, a green insoluble product is also formed during the reaction. A similar green solid (3e) is the major product of the reaction between TiCl4 and compound 2e. It can be isolated in approximately 80% yield from the reaction mixture. Complex 3e is soluble in dichloromethane from which dark green needles can be obtained. The 'H NMR spectrum (CD2C12) of complex 3e is very broad and remains unchanged at 50 °C. The determination of the magnetic susceptibility using Evans method87 showed that complex 3e is diamagnetic in solution. Attempts to isolate a suitable crystal for single crystal X-ray analysis References start on page 80 35 were thwarted by rapid loss of solvent molecules from the latdce. The 'H NMR spectrum of the hydrolysis product from complex 3e confirmed the presence of solvent in the crystal lattice. The nature of this green complex is uncertain but might be dimeric. The 'H NMR spectra of complexes 3a-d exhibit a singlet at approximately 5.8 ppm due to the ligand methylene protons (CH2N). This is consistent with the C2v symmetry and a meridional coordination of the ligand. A facial coordination of the ligand would yield a complex with C5 symmetry. In this case, the methylene (CH2N) protons would appear as an AB pattern in the 'H NMR spectrum. In contrast, a facial coordination geometry as been observed for [CH(2-C5H4N)(CH2NSiMe3)2]TiBr240_ The isopropyl methyl groups of complex 3a are diastereotopic. This has been interpreted as a consequence of restricted rotation about the N-Aryl C, bond (i.e. the methyl groups can not be made equivalent if the aryl can not rotate freely, Figure 1- 7). The proton NMR spectrum remains unchanged at 80 °C. It is not possible to determine by spectroscopic means if the same restricted rotation is present in compound 3b. N Figure J- 7. Restricted rotation of the aryl The isopropyl methine protons of complex 3d appear at an unusually high chemical shift (5 5.97 ppm) in the 'H NMR spectrum. Comparatively, the 'H NMR spectrum of the diamine 2d displays a septet at 3.26 ppm for the isopropyl methine protons. In a similar way, the cyclohexyl methine protons in the dichloride complex 3c appear as a broad triplet of triplets at 5.54 ppm compared to 2.82 ppm for the diamine 2c. References start on page 80 36 The consequence of the rigid coordination of the ligand is the enforced location of the substituents on the nitrogen. The type of protection afforded by the ligand is thus a function of the nature of these groups. With aryl substituents, a "pocket" opposite the pyridine ring is created and the metal is protected about the N3 plane. On the other hand, alkyl substituents protect the site trans to the pyridine and the faces (either sides of the N3 plane) are left open. 2.4 Synthesis of alkyl complexes Complexes 3a,b,d can be alkylated using various alkylating reagents (Scheme 1- 2). The addition of 2 equivalents of MeMgBr to ether suspensions of 3a,b,d at -78 °C affords the dimethyl derivatives 4a,b,d in good yield. Compounds 4a,b,d are thermally sensitive in the absence of coordinating ligands; for example, they can be crystallized readily from ether or THF but decompose slowly in toluene or benzene. Titanium dimethyl derivatives bearing amide ligands are believed to form transient methylidene species via a-elimination^O. Attempts to trap a methylidene complex by heating the dimethyl complexes in the presence of PMe3 were unsuccessful and no reaction was observed. The addition of 2.2 equivalents of MeMgBr or PhCH2MgCl to ether suspensions of complex 3e only gave small amounts (20-30% yield) of the corresponding Ti™ bis(alkyl) complex, (tBAP)TiMe, and (tBAP)Ti(CH,Ph)2 (detected by 'H NMR spectroscopy). No attempt was made to isolate these species. Moreover, the diamine 2e reacts very slowly with Ti(CH2SiMe3)489 at 80 °C to give (tBAP)Ti(CH2SiMe3)2 (< 5 % after 5 days) while rapid decomposition of the titanium tetra(alkyl) starting material is observed at higher temperature9^9^. References start on page 80 37 21a (V). / ^Cl ^NR 9b, R2 = CH2CMe2Ph 12b, R2 = Cp ^NR /\. V-'Me <\ N—Ti^ ^NR 4a,b,d A (i) /=^Kl V CI ^-NR 3a,b,d (IV) / -NR 6b, R3 = CH2Ph 8b, R3 = CH2SiMe3 ^^NR / ^Cl ^NR 5a, RT = CH2Ph 7a, R, = CH2SiMe3 9 ^NR i N—TL \_? / ^Cl \-NR 11a (a) R = 2,6-iPr2C6H3 (b) R = 2,6-Me2C6H3 (d) R = isopropyl Scheme 1- 2. Alkylation of complexes 2a,b,d¥ ¥ Reagents and conditions. (I) 2 equivalents MeMgBr, Et20, -78 °C; (II) 1 equivalent PhCH2MgCl or LiCH2SiMe3, EtjO, 22 °C; (III) 1.2 equivalents LiCH2C6H4-o-NMe2, Et,0, -78 °C; (TV) 2 equivalents PhCH2MgCl or LiCH2SiMe3, Et20, 22 °C; (V) 1 equivalent NaCp-DME or PhMe2CCH2MgCl, Et20, -30 °C; (VI) 1.2 equivalents (C4H6)Mg • 2THF, ElA -78 "C. The 'H NMR spectra of complexes 4a,b,d are similar to those obtained for compound 3a,b,d and are consistent with C2v symmetry. Additional resonances for the Ti-CH3 group are References start on page 80 38 observed at 1.06, 1.08 and 0.81 ppm, respectively. The diastereotopic isopropyl methyl resonances observed in the 'H NMR spectrum of complex 4a indicates that restricted rotation about the N-aryl Cipso bond is retained upon alkylation. The addition of 1.2 equivalents of (C4H6)Mg*2THF92 to an ether suspension of compound 3a at -78°C affords a mixture of the 1,3-butadiene complex 21a and black byproducts. It was not possible to isolate complex 21a from the impurities via crystallization. The 'H NMR spectrum of complex 21a displays two singlets at 5 5.19 and 4.98 ppm consistent with two inequivalent methylene groups (NC//2) on the ligands. This is interpreted as a result of asymmetry about the NMX2 plane (Figure 1- 8 II) and a complex with Cs symmetry. Two resonances at 5 5.28 ppm and 2.78 ppm are attributable to the butadiene fragment. It is not possible to discern the third butadiene resonance due to the resonances of the byproduct. Moreover, the difficulties associated with the purification of complex 21a prevented its characterization by 13C NMR spectroscopy. As a result, it is not possible to established the mode of coordination of the butadiene fragment. a (I) (II) Figure 1- 8. Mirror planes in complexes with C, symmetry References start on page 80 39 The addition of 1 equivalent of PhCH2MgCl, LiCH2SiMe3 or LiCH2C6H4-o-NMe2 to an ether suspension of the dichloride complex 3a at 22 °C yields the mono(alkyl) derivatives (BDPP)Ti(CH2Ph)Cl (5a), (BDPP)Ti(CH2SiMe3)Cl (7a) and (BDPP)Ti(CH2C6H4-o-NMe2)Cl (11a), respectively (Scheme 1- 2). The ligand methylene protons (CHAHBN) appear as AB quartet patterns in the 'H NMR spectra of complexes 5a,7a and 11a. This indicates asymmetry about the N3 plane (Figure 1- 8 I). Moreover, two isopropyl methine and four isopropyl methyl resonances are observed for complexes 5a, 7a and 11a, which is in agreement with the C5 symmetry of the complexes and the restricted rotation of the N-Cipso bond. Certain Ti111 complexes containing a CH2C6Ff4-o-NMe2 group are active catalysts for the polymerization of olefins^. Attempts to generate a Tim complex by reduction of 11a were unsuccessful yielding intractable materials. The addition of 2 equivalents of PhCH2MgCl or LiCH2SiMe3 to an ether suspension of 3b at 22 °C yields the bis(alkyl) derivatives (BDMP)Ti(CH2Ph)2 (6b) and (BDMP)Ti(CH2SiMe3)2 (8b), respectively (Scheme 1- 2). The 'H NMR spectra of complexes 6b and 8b display a singlet for the methylene protons (NCH2) of the ligand. This is in agreement with the expected C2v symmetry of the complexes. The addition of 1 equivalent of alkylating reagent in CH2C12 at -78 °C affords a 50% yield (by 'H NMR spectroscopy) of compounds 6b and 8b, respectively. The resonances attributable to the starting dichloride complexes (3a,b) are also observed. The addition of 1 equivalent of NaCp*DME to complex 3b in ether at -30 °C affords the r|5-cyclopentadienyl derivative 12b. No reaction is observed between the bulkier dichloride compound 3a and NaCp»DME. The 'H NMR spectrum of compound 12b is characteristic for a molecule with Cs symmetry. Rotation around the N-CI>i0 bond of the ligand is hindered by the presence of the Cp group resulting in two inequivalent arene methyl environments. Attempts to substitute the remaining chloride group using MeMgBr were unsuccessful. No reaction was observed between Mg metal and complex 12b. The use of stronger reducing agent such as Na or K metal or Na/K alloy yielded intractable materials. References start on page 80 40 The mono(alkyl) complex (BDMP)Ti(CH2CMe2Ph)Cl (9b) is obtained by the reaction of 2 equivalents of PhMe2CCH2MgCl with complex 3b and not the expected bis(neophyl) derivative. The 'H NMR spectrum (Figure 1-9) of complex 9b displays an AB quartet pattern for the methylene protons (CHAHhN) (©) and the two distinct aryl methyl (®/Q)) resonances. This is consistent with asymmetry about the MN3 plane in a complex with Cs symmetry (Figure 1-8 I) and restricted rotation about the N-Cf bond. No evidence of N-C1>JO bond rotation is observed at 80 °C. Attempts to grow X-ray quality crystals of complex 9b were unsuccessful. However, the bromide analogue 10b does provide suitable crystals. The bromide complex can be synthesized from complex 9b and MgBr^E^O) in ether (eq. 8). In fact, complex 10b was originally formed from the reaction of the dichloride derivative 3b and PhMe2CCH2MgCl contaminated with MgBr2(OEt2). The MgBr2(OEt2) was formed during the activation of the Mg turnings with 1,2-dibromoethane in the preparation of the Grignard reagent. The solid-state structure of 10b»C6H6 was determined by X-ray crystallography. The full crystallographic data can be found in the appendix. The molecular structure of complex 10b is shown in Figure 1- 10 and selected bond distances and angles in Table 1-1. References start on page 80 References start on page 80 42 Table 1- 1. Selected Bond Distances (A) and Angles (deg) for 8b*C6H6 Bond Distances Ti-Br 2.399(2) Ti-N(l) 1.979(5) Ti-N(2) 2.126(6) Ti-N(3) 1.977(6) Ti-C(8) 2.121(7) Bond Angles N(l)-Ti-N(3) 1412.1(2) Br-Ti-N(3) 100.3(2) C(8)-Ti-Br 102.8(2) Br-Ti-N(l) 98.1(2) C(8)-Ti-N(2) 101.4(3) Br-Ti(N(2) 155.8(2) C(8)-Ti-N(l) 102.7(3) C(8)-Ti-N(3) 105.1(3) The structure is best described as a distorted square pyramid with the neophyl carbon {C(8)} occupying the apical position (Figure 1- 10). The titanium atom is located about 0.48 A above the basal plane formed by the bromide, the two amides and pyridine nitrogen. The Ti-amide distances (1.979(5) and 1.977 (6)} A are comparable to those observed in other titanium amide complexes3^'-^40,94-97 The amide nitrogens are nearly sp2-hybridized as evidenced by the sum of the angles about each nitrogen atom (N(l) = 359.1° and N(3) = 359.3°}. The complex probably adopts a square based pyramidal structure over a trigonal bipyramid structure to minimize steric interactions between the neophyl group and the 2,6-dimethylphenyl substituents of the ligand. The rigid coordination of the ligand and the location of the aryl methyl groups create a protective "pocket" opposite the pyridine. The bromide is located in this "pocket" and is laterally shielded from incoming alkylating agents. This may explain the lack of reactivity of this compound with reagents such as MeMgBr. However, a small molecule such as H2(g> might be able to access the "pocket" and react. References start on page 80 43 Figure 1- 10. Top: Chem 3D™ drawing of the molecular structure of 8b'C^i6 {The benzene molecule is not shown.) Bottom: Chem 3D™ drawing of the core of Sb'CJif,. References start on page 80 44 In order to test this hypothesis, complexes 7a and 9b were exposed to approximately 3 atm of H2(g) (in C6D6) for 12 hours at ambient temperature. In both cases, a white solid precipitated from solution after a few hours. The insoluble materials were removed by centrifugation and the soluble products were characterized by 'H NMR spectroscopy. The 'H NMR spectrum of the solution obtained with compound 7a showed resonances characteristic of the parent dichloride complex (3a) as well as Me4Si and free pyridine diamine (la). Attempts to dissolve the white solid formed in the reaction in various solvents were unsuccessful (CD2C12, Pyridine-d5, THF-dg). A possible pathway for this reaction is shown in Scheme 1-3. The first step involves the hydrogenolysis of the Ti-C bond to form one equivalent of Me4Si and the transient mono(hydride) complex. The unstable mono(hydride) complex then decomposes to form 1/2 equivalent of the dichloride 3a, 1/2 equivalent of the diamine la (Scheme 1- 3, step A) and insoluble products. NR 7a NHR R = 2,6-'Pr2-C6H3 R, = CH2SiMe3 1/2 {/* NHR 1a + other insoluble products Scheme 1- 3. Proposed mechanism for the hydrogenation of complex 7a References start on page 80 45 The reaction between and complex 9b gave similar results. The 'H NMR spectrum of the soluble products displays resonances characteristic for free pyridine diamine (lb) and tert-butylbenzene. A similar pathway is proposed for this reaction (Scheme 1- 4). First, hydrogenolysis of the Ti-C bond affords one equivalent of te/^butylbenzene. The transient mono(hydride) complex then decomposes to give free pyridine diamine (lb) and insoluble Ti compounds. 9b R = 2,6-Me2-C6H3 RT = CH2CMe2Ph Decomposition NHR + other insoluble products NHR 1b Scheme J- 4. Proposed mechanism for the hydrogenation of complex 9b References start on page 80 46 2.5 Reduction of TiCl2 complexes: Metallacycle formation 2.5.1 Metallacyclopentadiene complexes derived from internal alkynes The reducdon of the dichloride complexes 3a,b with excess Na/Hg amalgam (1%) in toluene in the presence of >2 equivalents of internal alkyne (Scheme 1- 5) yields the tetrasubstituted metallacyclopentadiene complexes 13a, 14a and 15a,b. Complexes 13a, 14a and 15a,b can be recrystallized from pentane in good yield ¥Reagents and conditions: toluene, 23 °C, excess Na/Hg amalgam, > 2 equivalents alkyne. (I) R'GsCR', R' = Et, Pr, Ph. (II) R'C=CH, R' = SiMe3, Ph. (in) R'C=CH, R' = SiMe3. (I) 16a, R' = SiMe3 (a) R = 2,6-'Pr2C6H3 i6b) R- = siMe3 (b) R = 2,6-Me2C6H3 17a, R' = Ph Scheme 1- 5. Preparation of Titanacyclopentadiene derivatives* References start on page 80 47 (=65%). Attempts to isolate the titanacyclopentadiene complexes 13b {(BDMP)Ti(C4Et4)} and 14b {(BDMP)Ti(C4Pr4)} (not shown) were unsuccessful. They were observed by 'H NMR spectroscopy but they proved too soluble to be separated from the byproducts of the reacdon. The 'H NMR spectra of complexes 13a, 14a and 15a,b are consistent with a meridional coordination of the ligand and mirror symmetry about the N3-plane as evidenced by a singlet observed for the ligand methylene (NCH2) protons. The low-fields resonances (> 190 ppm) observed for the a-carbons of the metallacycle in the 13C{'H} NMR spectra are similar to previously reported values43,98,99 jhe low-field resonance observed for the a-carbon atom in complex 15b (5 221.7 ppm) is downfield from the one obtained for the metallocene analogue Cp,Ti(C4Ph4) (8 202.1 ppm). Comparatively, the a-carbon atoms in (Ar"0)2Ti(C4Ph4) (Ai" = 2,6-diphenylphenoxide) are observed at 225.0 ppm. Chemically inequivalent ethyl and propyl substituents (a and P positions) are observed for compounds 13a and 14a, respectively. The 'H NMR spectrum of compound 15a, however, is quite broad at 23 °C. A stacked plot of the ligand methylene (CH2N) region at various temperatures is shown in Figure 1-11. The low temperature limiting spectrum (-20 °C) shows an AB quartet (©) (2JHH = 20.6 Hz) for the ligand methylene (CHAHBN) protons and resonances at 4.99 ppm (©) and 2.79 ppm (not shown) attributable to two inequivalent isopropyl methine protons. As the temperature is increased, the isopropyl methine resonances coalesce to a single resonance at 3.88 ppm (not shown) while the resonance at 5.47 ppm (G)) shifts to lower field. The high temperature limiting spectrum (80 °C) shows a single broad resonance for the ligand methylene protons at about 5.05 ppm (©). This exchange process is interpreted as a result of synchronized restricted rotation of the phenyl rings of the titanacycle eq. 9. Using eq. 10^00 it is possible to calculate an approximate value for AG* of 14.7(5) kcal mol"1. References start on page 80 48 (10) Tc = coalescence temperature 8-u = distance between the peaks at slow exchange (Hz) h = Planck constant k = Boltzmann constant Rotation of the phenyl rings in the a and a' positions is hampered by the bulky 2,6-diisopropylphenyl substituents which in turn affects the orientation of the phenyl groups in the p and (3' positions of the titanacycle. The low temperature spectrum would be characteristic of a complex with C2 symmetry. Alternatively, the high temperature structure would have C2v symmetry. Comparatively, the less bulky titanacyclopentadiene complex 15b (R = 2,6-Me2C6H3) shows no restricted rotation at -80 °C. The solid-state structure of Cp2Ti(C4Ph4) shows a propeller arrangement of the phenyl rings as proposed here^l. Attempt to achieve cyclotrimerization using the titanacyclopentadiene complexes 13a, 14a and 15a,b were fruitless. These complexes do no react with excess alkyne or acetonitrile even at elevated temperatures (110 °C, 24 h). References start on page 80 49 References start on page 80 50 2.5.2 Metallacyclopentadiene complexes derived from terminal alkynes The reduction of the dichloride complexes 3a,b in the presence of terminal alkynes affords the metallacyclopentadiene complexes 16a,b and 17a (Scheme 1- 5). It is possible to rationalize the regiochemistry by assuming that the formation of compounds 16a,b and 17a proceeds via a common mono(alkyne) intermediate (Scheme 1- 6, compound I). R = 2,6-Me2-C6H3 R' = SiMe3, Ph R = 2,6-'Pr2-C6H3 R' = SiMe3 Scheme 1- 6. Regiochemistry of the insertion Steric interactions with the R' substituent (Ph or SiMe3) inhibit back-side attack of the second alkyne to the intermediate I. The incoming alkyne must then approach from the front. When the pyridine ligand bears the larger 2,6-diisopropylphenyl groups on nitrogen and the alkyne substituent is bulky (Me3Si), steric interactions between the R and R' groups direct the bulk of the alkyne away from the isopropyl group of the ligand and the a,[3' product is obtained References start on page 80 51 (16a). When the incoming alkyne is relatively small (HC=CPh), the more favorable oc,a' product is obtained (17a). Comparatively, with the smaller 2,6-dimethylphenyl substituents on the ligand, the alkyne inserts with the R' group pointing towards the ligand giving rise to the a,a' titanacycle(16b). Similar steric effects have been observed for related systems. For example, the phenyl groups in Cp2Ti(C4H2Ph2) are in the a and {3' positions while the an a,a' arrangement of methyl substituents is obtained with Cp2Ti(C4H2Me2)101. Rothwell and co-workers reported43,99 that in some cases a,(3 substituted titanacyclopentadiene can rearrange to the more thermodynamically favored a,a' isomer. Compounds 16a,b and 17a do not isomerize when heated to 80 °C in benzene. The solid-state structure of complex 16a was determined by X-ray crystallography. Complete crystallographic data can be found in the appendix. The molecular structure of complex 16a is shown in Figure 1-12 and selected bond distances and angles in Table 1- 2. Table 1- 2. Selected Bond Distances (A) and Angles (deg) for Complex 16b Bond Distances Ti(l)-C(l) 2.046(11) Ti(l)-C(4) 2.070(10) Ti(l)-N(l) 1.989(8) Ti(l)-N(2) 2.009(8) Ti(l)-N(3) 2.172(8) C(l)-C(2) 1.348(13) C(2)-C(3) 1.553(14) C(3)-C(4) 1.357(13) Bond Angles N(2)-Ti(l)-N(3) 74.1(3) C(l)-Ti(l)-C(4) 100.7(4) N(2)-Ti(l)-N(l) 141.5(3) N(3)-Ti(l)-N(l) 73.6(3) Ti(l)-N(3)-C(l) 155.6(4) Ti(l)-N(3)-C(4) 103.6(4) C(30)-N(l)-C(17) 109.8(7) C(18)-N(2)-C(ll) 112.3(7) C(17)-N(l)-Ti(l) 121.8(6) Ti(l)-N(2)-C(ll) 122.1(6) Ti(l)-N(l)-C(30) 128.3(6) Ti(l)-N(2)-C(18) 125.3(6) References start on page 80 52 Figure 1- 12. Top: Chem 3D™ representation of the molecular structure of 16b. Bottom: Chem 3D™ representation of the core of 16b References start on page 80 53 As previously noted for compound 9b, the structure of the titanacyclopentadiene complex 16a is also best described as a distorted square base pyramid with the metallacycle carbon C(4) occupying the apical position. The titanium lies approximately 0.45 A above the basal plane defined by the three nitrogen atoms and C(l). The Ti-amide distances are comparable to those observed in complex 9b. Finally, the short-long-short {1.348(13)-1.553(14)-1.357(13)} bond distances and the planarity of the metallacycle are consistent with its diene formulation. Similar geometrical parameters have been reported for titanacyclopentadienes supported by alkoxide" or cyclopentadienyl ^01 ligands. It has been proposed that the mechanism for the cyclotrimerization of alkyne using early transition metal complexes proceeds through a Diels-Alder "7-metallanorbornadiene" adduct83. This type of intermediate requires attack of the incoming alkyne on one of the two faces of the metallacyclopentadiene. The structure of complex 16a (Figure 1- 12) demonstrates the steric congestion created by the 2,6-diisopropylphenyl group about the N3 plane. Approach of a third alkyne on either face of the metallacycle is thwarted by the sterically demanding ligand. This may explain the lack of insertion chemistry observed with this complex. Unlike compounds 13-17a and 15b which do not react with excess alkyne (110 °C, 24 h), compound 16b reacts with excess alkyne at 80 °C to give the asymmetric metallacycle derivatives 18b and 19b in quantitative yield by ]H NMR spectroscopy (eq. 11). The 'H NMR spectrum of compound 18b is shown in Figure 1- 13. (H) 16b 18b, Y=Et R = 2,6-Me2C6H3 19b, Y = Pr R' = SiMe3 References start on page 80 References start on page 80 55 The substitution pattern of the metallacycle was established based on the results of NOE experiments. For example, irradiation of the C//2Me signal at 2.14 ppm (Figure 1- 13 ©) caused the enhancement of the metallacycle proton resonance at 8.23 ppm (Figure 1- 13 ®). Irradiation of other groups was consistent with this assignment. This is in agreement with the metallacycle proton being in proximity to one of the ethyl groups. Two mechanisms have been proposed for the substitution of alkynes in metallacyclopentadiene complexes. The fragmentation of the metallacycle to an intermediate bis(alkyne) complex has been proposed to explain the exchange of alkyne in (Ar"0)2Ti(C4Et4)43,99 (Scheme 1- 7, path A). The other approach involves the dissociation of the metallacycle into a mono(alkyne) adduct and free alkyne (Scheme 1- 7, path B). This pathway has been proposed for alkyne exchange in tantalum alkoxide systems^2. + pseudo SN1 'RCEECR' Scheme 1- 7. Proposed mechanisms for alkyne exchange It is not possible to distinguish which mechanism is operative in the formation of complexes 18b and 19b. It is, however, important to note that only one of the original alkynes is substituted. The steric congestion of the tri-substituted metallacycle obtained might explain the References start on page 80 56 lack of further exchange. Furthermore, with the more sterically imposing 2,6-diisopropylphenyl ligand, no evidence of alkyne exchange was observed. 2.6 Reduction of titanium dichloride complexes: ligand C-H bond activation As mentioned above, the reduction of complex 3b in the presence of 3-hexyne or 4-octyne yields a mixture of compounds from which the desired metallacycle can be observed by spectroscopic means. However, when the reduction is performed in the presence of MeCsCPh, the side product (20b) is formed in high yield and can be isolated. The "H NMR spectrum of compound 20b as well as the signal assignments are shown in Figure 1- 14. The spectrum displays two AB quartet patterns for the ligand methylene protons (<3) ,NCrYA//B). This indicates that all four protons are inequivalent and that the complex has Cl symmetry. Moreover only three resonances attributable to the ligand aryl methyl groups are observed (®). A combination of 'H homonuclear decoupling experiments (Figure 1- 15) and 'H-13C heteronuclear correlation spectroscopy (Figure 1- 16) were used in proposing a structure for complex 20b. The quartet at 3.64 ppm (Q)) collapses to a singlet upon irradiation of the doublet at 1.97 ppm (©) (Figure 1- 15). These signals are attributable to a vinyl moiety resulting from the insertion of MeC^CPh into a Ti-H bond (Ti-C(Ph)=CHMe). A coupling of 6.2 Hz is observed between the vinylic C-H and the methyl group, characteristic for this type of fragment 1^2 The proposed mechanism for the formation of complex 20b is shown in Scheme 1- 8. In the first step, the Ti™ dichloride precursor is reduced to a Tin complex (A). This intermediate then activates the methyl group of the arene to yield a Ti-H complex (B). Presumably, the isopropyl methine in complex 3a is well protected by the isopropyl methyl groups and this activation does not occur. A molecule of PhC=CMe is then inserted into the newly formed titanium-hydride bond to generate the vinyl moiety shown in C. References start on page 80 57 Scheme 1- 8. Proposed mechanism for the formation of complex 20b Insertion of a second equivalent of PhC^CMe into the Ti-C bond of complex C followed by a 1,3-hydrogen shift yields the final product 20b. The proton shift may occur in an attempt to relieve ring strain. Attempts to isolate a Tin complex by the reduction of complex 3a,b in the presence of a donor ligand such as PMe3 or pyridine were unsuccessful. It is not clear why this ligand-activated complex forms in such high yield with certain alkynes. There is no evidence of the formation of a similar product when the dichloride complex 3b is reduced in the presence of diphenylacetylene or trimethylsilylacetylene. This type of ligand activation may prove to be one of the major drawback in the use of these complexes for the catalytic cyclization of alkynes since Tin species are key intermediates. References start on page 80 58 rro t-oo References start on page 80 59 60 JLA F2 (PPM) 130 120 -110 -100 -90 80 H 70 60 50 40 30 -\ 20 1^ Figure 1- 16. 'H "C HETCOR spectrum of complex 20b (300 MHz, CJDJ References start on page 80 61 2.7 Zwitterionic complex and reaction with olefins. The reaction of complex 16a with 1 equivalent of B(C6F5)3 in pentane at low temperature results in the formation of the zwitterionic complex eq. 12). (12) R = 2,6-diisopropylphenyl 16a 22a Restricted rotation about the Ti-vinyl bond is advanced to account for the observed Cs symmetric geometry. This is consistent with the AB pattern observed for the ligand methylene protons (CH2N) in the 'H NMR spectrum of compound 22a . Four isopropyl methine and eight isopropyl methyl resonances are observed as a consequence of restricted rotation about the N-Cipso. Two low field resonances (9.29 and 8.07 ppm) are assigned to the two dienyl protons (CH). The resonance at 9.29 ppm appears as a multiplet possibly a result of long range coupling to 19F. This is consistent with the borane attacking the least substituted a-carbon of the metallacycle complex. In the absence of 19F NMR data, it is not possible to establish with certainty the nature of complex 22a but a similar titanocene-based complex has been structurally characterized 103 Erker and co-worker!04 reported the unusual reactivity of B(C6F5)3 with the metallacyclopentadiene derivative Cp2Zr(C4Me4). They showed that the borane did not attack the a-carbon atoms of the metallacycle but one of the carbon of the Cp rings to form a zirconocene-betaine system. The steric protection offered by the 2,6-diisopropylphenyl group of the ligand in complex 16a may explain the difference in reactivity. The amide groups are sterically protected and the borane can only attack the a-carbon atoms of the metallacycle. References start on page 80 62 Attempts to generate a similar compound from metallacycle 16b and B(C6F5)3 were unsuccessful. This might be a result of both a-carbons being protected by the large SiMe3 groups. No reaction is observed upon addition of excess 1-hexene or ca. 3 atm. of ethylene to complex 22a in pentane or toluene. Similarly, no reaction is observed when complex 16a is heated to 60 °C in the presence of 1-hexene. However, a small amount of a white insoluble material is obtained when complex 16b is heated to 60 °C in the presence of 3 atm. of ethylene. The insolubility of the white material prevented its identification by 'H NMR spectroscopy. It has already been shown that [(ArO)2Ti(C4Et4)] (Ar = 2,6-diphenylphenoxide) reacts with ethylene to produce [(ArO)2Ti(C4H8)] along with 1 equiv of a substituted 1,3-cyclohexadiene (eq. 13)105. We see no evidence for the formation of (BDMP)Ti(C4Hg) or l,3-bis(trimethylsilyl)l,3-hexadiene. Complex 16b did not react with 1-hexene. R (13) R References start on page 80 63 3 Conclusions Pyridine diamide complexes of titanium can be synthesized in high yield from TiCl4 and the silylated compound 2a,b using the elimination of Me3SiCl as a driving force for the reaction. Both mono(alkyl) and bis(alkyl) complexes are stabilized by this pyridine diamide ligand system. However, the dimethyl derivatives are thermally unstable. The dichloride complexes can be reduced in the presence of internal and terminal alkynes to give the corresponding metallacyclopentadiene derivatives in good yield. No reaction is observed between the titanacyclopentadiene complexes 13-17a, and 15b and excess alkyne or acetonitrile. On the other hand, alkyne exchange has been observed with complex 16b. The symmetrical metallacycles (LnTiC4R4, R = Et, Pr) are formed in low yield. The activation of the methyl groups of the ligand appears to compete with the formation of the desired metallacycle. The bulkier 2,6-diisopropylphenyl ligand does not engage in ligand activation. However, the steric bulk of the ligand precludes further reactivity of the metallacyles. References start on page 80 64 4 Experimental Details General Details. All experiments were performed under a dry dinitrogen atmosphere using standard Schlenk techniques or in an Innovative Technology Inc. glovebox. Solvents were distilled from sodium/benzophenone ketyl (DME, THF, hexanes, diethylether and benzene) or molten sodium (toluene) under argon and stored over activated 4A molecular sieves. Titanium(IV) chloride and methylmagnesium bromide were purchased from Aldrich and used as received. Phenylacetylene, diphenylacetylene, 1-phenylpropyne, 3-hexyne, 4-octyne, trimethylsylilacetylene, 2,6-diisopropylaniline, 2,6-dimethylaniline, cyclohexylamine, iso-propylamine, fm-butylamine, triethylamine, chlorotrimethylsilane, bromotrimethylsilane were purchased from Aldrich and distilled before use. A CH2C12 solution of 2,6-bis(bromomethyl)pyridine,HBr86 was extracted with NaHC03 to yield 2,6-bis(bromomethyl)pyridine. LiNR(SiMe3) (R = 2,6-'Pr2C6H3, 2,6-Me2C6H3) was prepared as noted in the literature^. MgBr2»2EL,0 was made from Mg and BrCH2CH2Br in ether. The Me3SiCH2Li107, Li(CH2C6H4-o-NMe2)108, Mg(C4H6)«2THF92 and NaC5H5'DMEl09 were prepared using previously reported syntheses. Proton (300 MHz) and carbon (75.46 MHz) NMR spectra were recorded in C6D6 at approximately 22 °C on a Varian Gemini-300 or 300-XL spectrometer. The proton chemical shifts were referenced to internal C6D5.rY (8 = 7.15 ppm) and the carbon resonances to C6D6 (8 = 128.0 ppm). The elemental analysis were performed using sealed tin cups on a Fisons Instruments model 1108 elemental analyzer by Mr. Peter Borda of UBC or by Oneida Research Services Inc., Whitesboro, NY. 2,6-(RHNCH2)2-NC5H3, (R = 2,6-diisopropylphenyl), (BDPP)H2 (la). A THF (150 mL) solution of LiNHR (12.226 g, 66.77 mmol) was added slowly to a THF (100 mL) solution of 2,6-bis(bromomethyl)pyridine (8.842 g, 33.37 mmol) at -78 °C. The mixture was allowed to warm to room temperature and stirred for 12 h. The solution was quenched with a saturated NaHC03 solution (100 ml) and extracted with diethyl ether. The solvent was removed References start on page 80 65 in vacuo to yield a yellow-brown viscous liquid. The oil was then dissolved in hot hexanes and cooled to -30 °C. White crystalline la was isolated by filtration and dried under vaccum (7.792 g, 17.02 mmol, 51%). 'H NMR 8 7.20-7.10 (m, 6H, Ar), 7.12 (j, IH, py), 6.84 (d, 2H, py), 4.24 (s, 4H, NC/72), 4.21 (br s, 2H, N/7), 3.53 (sept, 4H, CHMeJ, 1.24 (d, 24H, CHMe2). 13C{'H} NMR 8 158.21, 154.18, 143.27, 137.25, 125.12, 124.17, 121.16, 57.02, 28.24, 24.62. MS (EI) m/z 457.346 (M+). Calcd for C31H43N3: 457.346 2,6-(RHNCH2)2-NC5H3, (R = 2,6-dimethylphenyl), (BDMP)H2 (lb). The preparation of compound lb is identical to that of la. LiNHR (2.879 g, 22.65 mmol) and 2,6-bis(bromomethyl)pyridine (3.000 g, 11.32 mmol) yield a yellow-brown viscous liquid (3.105 g, 8.987 mmol, 79%). JH NMR 8 7.05-6.95 (m, 5H, Ar and py), 6.86 (m, 2H, Ar), 6.67 (d, 2H, py), 4.21 (br s, 2H, N//), 4.15 (s, 4H, NC/72), 2.25 (s, 12H, Me). 13C{'H} NMR 8 159.04, 146.88, 136.72, 18.50, 129.24, 122.18, 120.24, 53.93, 18.87. MS (EI) m/z 345.220 (M+). Calcd for C„H27N3: 345.220. 2,6-(RHNCH2)2-NC5H5 (R = cyclohexyl) (CyAP)H2 (lc). Solid 2,6-bis(bromomethyl)pyridine (5.000 g, 18.87 mmol) was added to a solution of cyclohexylamine (10.(X) g, 100.8 mmol) in hexanes (50 mL). The solution got warm and a white solid started to form within minutes. The solution was stired for 12 hours at 23 °C and was quenched with 100 mL of a saturated aqueous NaHC03 solution and extracted with CH2C12. The solvent was removed in vacuo to yield a light yellow liquid lc (4.800 g, 15.92 mmol, 84 %). 'H NMR 8 7.23 (t, IH, py), 7.04 (d, 2H, py), 3.90 (s, 4H, NO/2), 2.39 (br m, 2H, NC//(CH2)2), 1.81 (br m, 4H, Cy), 1.61 (br m, 4H, Cy), 1.12 (br m, 2H, Cy), 1.04 (br m, 8H, Cy). 13C {'H} NMR 8 160.88, 136.38, 120.00, 56.68 ('JCH = 131 Hz), 53.00, 34.00, 26.70, 25.18. MS (EI) m/z 300.243 {(M-l)+}. Calcd. for C19H30N3 : 300.244. 2,6-(RHNCH2)2-NCsH5 (R = iso-propyl) (iPAP)H2 (Id). The preparation of compound Id is identical to that of lc. 2,6-bis(bromomethyl)pyridine (5.000 g, 18.87 mmol) and cyclohexylamine (10.00 g, 169.2 mmol) yield a yellow liquid Id (7.820 g, 18.75 mmol, 99 References start on page 80 66 %). 'H NMR 8 7.20 (t, 1H, py), 7.02 (d, 2H, py), 3.86 (s, 4H, NCH2), 2.70 (sept, 2H, C//Me2), 1.56 (brs, 2H, NH), 0.97 (s, 12H, CHMe2). 13C {'H} NMR 8 160.65, 136.34, 119.99, 53.45, 48.64 ('JCH = 130 Hz), 23.27. MS (EI) m/z 221.187 (M)\ Calcd. for C13H23N3 : 221.189. 2,6-(RHNCH2)2-NCsH5 (R = tert-buty\) (tBAP)H2 (le). The preparation of compound le is identical to that of lc. 2,6-bis(bromomethyl)pyridine (5.000 g, 18.87 mmol) and r-butylamine (10.00 g, 136.7 mmol) in hexanes (50mL) yield a light yellow liquid le (4.580 g, 18.36 mmol, 97 %). 'H NMR 8 7.16 (m, 1H, py), 7.14 (d, 2H, py), 3.89 (s, 4H, NCtf2), 1.55 (br s, 2H, NH), 1.05 (s, 18H, f-Bu). 13C {'H} NMR 8 161.07, 135.44, 120.10, 50.35, 49.09, 29.23. MS (EI) m/z 249.221 (M+). Calcd. for C15H27N3 : 249.221. 2,6-[RN(SiMe3)CH2]2-NC5H3(R = 2,6-diisopropylphenyl), (BDPP)(SiMe3)2 (2a). A DME (150 mL) solution of LiNR(SiMe3) (8.820 g, 35.53 mmol) was added slowly to a DME (100 mL) solution of 2,6-bis(bromomethyl)pyridine (4.621 g, 17.44 mmol) at -30 °C. The mixture was allowed to warm to room temperature and stirred for 12 h. The solvent was removed in vacuo and the resulting solid extracted with hexanes (3 x 100 mL) and filtered through Celite. The volume of the filtrate was reduced to 50 mL and cooled to -30 °C for 12 h. A white crystalline solid was isolated by filtration and dried under vacuum (4.530 g, 7.502 mmol, 44%). 'H NMR 8 7.15 (t, 2H, Ar), 7.02 (d, 4H, Ar), 6.48 (t, 1H, py), 6.47 (d, 2H, py), 4.28 (s, 4H, NCH2), 3.31 (sept, 4H, C#Me2), 1.17 (d, 12H, CHMe2), 0.90 (d, 12H, CHMe2), 0.27 (s, 18H, SiMe3). 13C{'H} NMR 8 159.88, 148.69, 143.40, 135.88, 126.30, 124.24, 122.28, 58.78, 27.94, 25.18, 1.06. MS (EI) m/z 601.423 (M+). Calcd for C37H59N3Si2: 601.424. 2,6-[RN(SiMe3)CH2]2-NC5H3, (R = 2,6-dimethylphenyl) (BDMP)(SiMe3)2 (2b). The preparation of compound 2b is identical to that of compound 2a. LiNR(SiMe3) (4.500 g, 23.30 mmol) and 2,6-bis(bromomethyl)pyridine (3.083 g, 11.73 mmol) gave a white crystalline solid (2b) (2.389 g, 4.882 mmol, 42%). 'H NMR 8 6.98-6.88 (t, 6H, Ar), 6.72 (t, 1H, py), 6.34 (d, 2H, py), 4.18 (s, 4H, NC//2), 2.01 (s, 12H, Me), 0.23 (s, 18H, SiMe3). References start on page 80 67 13C{'H} NMR 8 159.89, 146.32, 138.22, 135.54, 128.74, 125.09, 121.51, 56.50, 19.30, 0.87. MS (EI) m/z (M+) 489.300. Calcd for C29H43N3Si2: 489.300. 2,6-[RN(SiMe3)CH2]2-NC5H3, (R = cyclohexyl) (CyAP)(SiMe3)2 (2c). ClSiMe3 (3.243 g, 29.85 mmol) was added dropwise to a diethylether solution (50 mL) of (CyAP)H2 (3.000 g, 9.951 mmol). The reaction mixture was stired at room temperature for 12 hours. A solution of Et3N (5.035 g, 49.76 mmol) in diethylether (50 mL) was added to the reaction mixture which was stirred for 12 hours. The solvent was removed in vacuo. The white solid was then extracted with hexanes (500 mL). The volume of the solution was reduced to 25 mL and the solution cooled to -30 °C for 12 hours. White crystalline 2c was isolated by filtration and dried in vacuo (3.987 g, 8.943 mmol, 90 %). 'H NMR 8 7.30 (m, 3H, py), 4.28 (s, 4H, NC//2), 2.82 (tt, 2H, NC/Y), 1.28 (m, 8H, Cy), 1.40 (m, 6H, Cy), 1.09 (m, 4H, Cy), 0.85 (m, 2H, Cy), 0.17 (s, 18H, SiMe3). 13C{'H} NMR 5 164.56, 135.95, 118.57, 57.59, 50.20, 33.99, 26.88, 26.00, 0.84. MS (EI) m/z (M-l)+ 444.323. Calcd for C25H46N3Si2: 444.323. 2,6-[RN(SiMe3)CH2]2-NCsH„ (R = isopropyl) (iPAP)(SiMe3)2 (2d). The preparation of compound 2d is similar to that of compound 2c. (iPAP)H2 (2.000 g, 9.036 mmol), BrSiMe3 (4.565 g, 29.82 mmol) and Et3N (4.574 g, 45.20 mmol) gave a white low melting solid (2d) (3.250 g, 8.887 mmol, 98 %). 'H NMR 5 7.28 (t, IH, py), 7.19 (d, 2H, py), 4.14 (s, 4H, NC/72), 3.28 (sept, 2H, NO/Me2), 0.94 (d, 12H, NCHMe2), 0.12 (s, 18H, SiMe3). 13C{'H} NMR 5 164.35. 135.89. 118.50. 48.89. 48.03. 22.94. 0.62. MS (EI) m/z (M+) 365.265. Calcd for C19H39N3Si2: 365.268. 2,6-[RN(SiMe,)CH2]2-NC5H3, (R = t-butyl) (tBAP)(SiMe3)2 (2e). The preparation of compound 2e is identical to that of compound 2c. (tBAP)H2 (2.500 g, 10.02 mmol), BrSiMe3 (5.064 g, 33.08 mmol) and Et3N (5.060 g, 50.00 mmol) gave a white crystalline solid (2e) (3.895 g, 9.894 mmol, 99 %). 'H NMR 8 7.33 (m, 4H, py), 4.32 (s, 4H, NC//2), 1.11 (s, 18H, CMe3), 0.21 (s, 18H, SiMe3). 13C{'H} NMR 8 162.28, 136.08, 118.02, 54.69, 51.92, 30.88, 4.10. MS (EI) m/z (M+) 393.298. Calcd for C21H43N3Si2: 393.300. References start on page 80 68 (BDPP)TiCl2 (3a). Liquid TiCl4 (1.850 g, 9.752 mmol) was added in small portions to a toluene (50 mL) solution of BDPP(SiMe3)2 (5.880 g, 9.737 mmol) at -40 °C. The solution immediately turned bright red and was heated to 80 °C for 12 h. The solution was filtered through Celite and the solvent removed in vacuo. The resulting solid was washed with cold hexanes (3 x 50 mL) to yield a bright red powder (4.450 g, 7.747 mmol, 80%). 'H NMR 6 7.14 (m, 6H, Ar), 6.75 (t, IH, py), 6.27 (d, 2H, py), 4.87 (s, 4H, NC//2), 3.75 (sept, 4H, CHMe2), 1.53 (d, 12H, CHMe2), 1.19 (d, 12H, CUMe2). 13C{'H} NMR 5 161.58, 154.08, 142.83, 138.88, 124.80, 117.56, 103.30, 70.60, 28.58, 26.33, 25.12. Anal, calcd. for C31H41N3TiCl2: C, 64.81; H, 7.19; N, 7.31. Found: C, 64.35; H, 7.08; N, 6.95. (BDMP)TiCl2 (3b). The preparation of compound 3b is identical to that for compound 3a. TiCl4 (2.35 mL , 1.04 M, 2.444 mmol) and compound 2b (1.088 g, 2.223 mmol) gave a bright red solid (2b) (0.839 g, 1.815 mmol, 82%). ]H NMR 5 7.05-6.95 (m, 6H, Ar), 6.85 (t, IH, py), 6.36 (d, 2H, py), 4.52 (s, 4H, NC/72), 2.42 (s, 12H, Me). 'H NMR (CD2C12) 6 8.09 (t, IH, py), 7.58 (d, 2H, py), 7.15-7.00 (m, 6H, Ar), 5.8 (s, 4H, NC//2), 2.32 (s, 12H, Me). 13C{'H} NMR (CD2C12) 5 163.51, 154.50, 140.29, 133.54, 129.22, 126.91, 118.96, 69.13 (CH2N), 19.48. (CyAP)TiCl2 (3c). The preparation of compound 3c is identical to that for compound 3a. TiCl4 (0.247 g, 1.302 mmol) and compound 2c (0.580 g, 1.301 mmol) gave an orange crystalline solid (3c) (0.273 g, 0.653 mmol, 50 %) when recrystalized from CH2C12 at -30 °C. 'H NMR 5 7.06 (t, IH, py), 6.58 (d, 2H, py), 5.54 (tt, 2H, NCH), 4.42 (s, 4H, NC/72), 2.30 (d, 4H, Cy), 1.80 (d, 4H, Cy), 1.55 (m, 6H, Cy), 1.10 (m, 6H, Cy). 13C{'H} NMR 6 164.60, 137.63, 117.51, 62.79, 61.27, 30.50, 26.94, 26.49. (iPAP)TiCl2 (3d). The preparation of compound 3d is identical to that for complex 3a. TiCl4 (1.073 g, 5.656 mmol) and compound 2d (1.880 g, 5.140 mmol) gave bright orange crystalline 3d (1.257 g, 3.717 mmol, 72 %). 'H NMR 5 6.95 (t, IH, py), 6.47 (d, 2H, py), References start on page 80 69 5.97 (sept, 2H, NC//Me2), 4.31 (s, 4H, NC//2), 1.22 (d, 12H, NCHMe2). 13C{'H} NMR 5 164.58, 137.46, 117.51, 59.61, 53.80, 19.57. (tBAP)TiCl (3e). Liquid TiCl4 (0.096 g, 0.506 mmol) was added in small portions to a toluene (50 mL) solution of (tBAP)(SiMe3)2 (0.200 g, 0.508 mmol) at -40 °C. The solution immediately turned bright red then green and was heated to 80 °C for 12 h. The solution was filtered through Celite and the solvent removed in vacuo. The resulting solid was washed with cold hexanes (3 x 50 mL) to yield a green powder. The green powder was dissolved in a minimum ammount of CH2C12 and cooled to -30 °C. Compound 3e was isolated by filtration as a dark green crystalline solid and dried under vaccum (0.183 g, 0.405 mmol, 80 % based on the formulation (tBAP)TiCl, • CH2C12). (BDPP)TiMe2 (4a). To a diethyl ether (25 mL) suspension of compound 3a (0.500 g, 0.870 mmol) was added 2 equiv of MeMgBr (0.58 mL, 3.0 M, 1.7 mmol) at -78 °C. The solution changed from orange to dark red within minutes and was stirred for 12 h. The solvent was removed in vacuo. The resulting solid was extracted with toluene (3 x 10 mL) and filtered through Celite to give a red-brown solution. The solvent was removed in vacuo, the solid dissolved in a minimum amount of diethyl ether, and cooled to -30 "C for 12 h. Bright yellow crystalline 4a was isolated by filtration and dried under vacuum (0.314 g, 0.461 mmol, 53%). The solid is thermally and photolytically sensitive and was stored at -40 °C in the dark to prevent decomposition. 'H NMR 5 7.02 (m, 6H, Ar), 6.76 (t, 1H, py), 6.30 (d, 2H, py), 4.98 (s, 4H, NC//2), 3.69 (sept, 4H, CHUe2), 1.28 (d, 12H, CHMe2), 1.11 (d, 12H, CHMe2), 1.06 (s, 6H, TiMe). 13C{'H} NMR 5 162.93, 145.41, 137.87, 129.29, 126.33, 124.51, 117.03, 68.33, 64.40 (TiCH3), 28.11, 28.04, 24.35. (BDMP)TiMe2 (4b). The preparation of complex 4b is identical to that of compound 4a. Complex 3b (0.100 g, 0.216 mmol) and MeMgBr (0.2 mL, 2.40 M, 0.48 mmol) gave a bright yellow crystalline solid (4b) (0.072 g, 0.171 mmol, 79%). The solid is thermally and photolytically sensitive and was stored at -40 "C in the dark to prevent decomposition. 'H NMR 5 References start on page 80 70 7.21 (d, 4H, Ar), 7.08 (t, 2H, Ar), 6.91 (t, IH, py), 6.47 (d, 2H, py), 4.73 (s, 4H, NC/72), 2.38 (s, 12H, Me), 1.08 (s, 6H, TiMe). 13C{'H} NMR d 163.49, 153.08, 137.50, 135.09, 129.09, 125.41, 117.13, 65.96, 62.28, 18.62. (iPAP)TiMe2 (4d). The preparation of complex 4d is identical to that of compound 4a. Complex 3d (0.250 g, 0.739 mmol) and MeMgBr (0.62 mL, 3.0 M, 1.9 mmol) gave a bright yellow crystalline solid (4d) (0.152 g, 0.511 mmol, 69 %). The solid is thermally and photolytically sensitive and was stored at -40 °C in the dark to prevent decomposition. 'H NMR 8 6.92 (t, IH, py), 6.53 (d, 2H, py), 5.92 (sept, 2H, NC#Me2), 4.59 (s, 4H, NC#2), 1.44 (d, 12H, NCHMe2), 0.81 (s, 6H, TiMe). 13C{'H} NMR 8 164.52, 136.37, 116.91, 57.00, 50.36 ('JCH = 133 Hz), 45.12, 21.17. (BDPP)Ti(CH2Ph)Cl (5a). To a diethyl ether (30 mL) suspension of compound 3a (0.500 g, 0.870 mmol) was added 1 equiv of PhCH2MgCl (0.62 mL, 1.4 M, 0.87 mmol) at 23 °C. The solution changed from orange to dark red within minutes and was stirred for 12 h. The solvent was removed in vacuo. The resulting solid was extracted with toluene (3 x 10 mL) and fdtered through Celite to give a red-brown solution. The solvent was removed in vacuo, the solid dissolved in a minimum amount of hot hexanes, and cooled to -40 °C for 12 h. Dark red crystalline 5a was isolated by filtration and dried under vacuum (0.418 g, 0.663 mmol, 75%). 'H NMR 8 7.30-7.17, 6.90, 6.80 and 6.54 (Ar and CH2Ph), 6.69 (t, IH, py), 6.19 (d, 2H, py), 4.92 (AB quartet, ^ = 22.7 Hz, 4H, NC/72), 4.71 (sept, 2H, C#Me2), 3.72 (s, 2H, C#2Ph), 3.09 (sept, 2H, C//Me2), 1.60 (d, 6H, CHMe2), 1.52 (d, 6H, CHM<?2), 1.30 (d, 6H, CHMe2), 1.06 (d, 6H, CHMe2). 13C{'H} NMR 8 161.57, 154.84, 149.49, 143.83, 142.69, 138.27, 127.52, 126.66, 125.30, 124.52, 124.39, 121.81, 117.04, 79.89, 69.41, 28.87, 26.17, 25.79, 24.96, 24.81. Anal. Calcd for C38H45N3TiCl • C6H14: C, 73.78; H, 8.72; N, 5.87. Found: C, 73.98; H, 8.42; N, 5.90. (BDMP)Ti(CH2Ph)2 (6b). To a diethyl ether (30 mL) suspension of compound 3b (0.100 g, 0.216 mmol) was added 2.2 equiv of PhCH2MgCl (2.2 mL, 0.22 M, 0.48 mmol) at 23 References start on page 80 71 °C. The solution changed from orange to dark red within minutes and was stirred for 12 h. The solvent was removed in vacuo. The resulting solid was extracted with toluene (3 x 10 mL) and filtered through Celite to give a red-brown solution. The volume of the solvent was reduced (5 mL) and the solution cooled to -40 °C. Dark red crystalline 6b was isolated by filtration (0.089 g, 0.124 mmol, 72%). 'H NMR 8 7.17 (d, 4H, Ar), 7.05 (m, 2H, Ar), 6.88 (t, 4H, CH2P/i), 6.77 (t, 1H, py), 6.62 (t, 2H, CU2Ph), 6.60 (d, 4H, CH2Ph), 6.25 (d, 2H, py), 4.59 (s, 4H, NCH2), 2.62 (s, 4H, C//2Ph), 2.46 (s, 12H, Me). 13C{'H} NMR 5 161.85, 156.88, 145.89, 137.83, 134.43, 129.26, 128.63, 125.49, 124.81, 122.31, 118.16, 116.83, 65.49, 19.92. (BDPP)Ti(CH2SiMe,)Cl (7a). To a diethyl ether (30 mL) suspension of compound 3a (0.500 g, 0.870 mmol) was added 1 equiv of LiCH2SiMe3 (0.082 g, 0.871 mmol) at 23 °C. The solution changed from orange to yellow within minutes and was stirred for 12 h. The solvent was removed in vacuo. The resulting solid was extracted with toluene (3 x 10 mL) and filtered through Celite. The solvent was removed in vacuo, the solid dissolved in a minimum amount of diethyl ether and cooled to -40 °C for 12 h. Yellow crystalline 7a was isolated by filtration and dried under vacuum (0.430 g, 0.687) mmol, 79%). ]H NMR 8 7.25-7.15 (Ar), 6.83 (t, 1H, py), 6.38 (d, 2H, py), 5.07 (AB quartet, 2JHH = 22.0 Hz, 4H, NC//2), 4.39 (sept, 2H, CtfMe2), 3.25 (sept, 2H, C//Me2), 2.89 (s, 2H, C#2Si), 1.54 (d, 6H, CHMe2), 1.45 (d, 6H, CHMe2), 1.40 (d, 6H, CHMe2), 1.11 (d, 6H, CHMe2), -0.18 (s, 9H, Si(C#3)3). 13C{'H} NMR 8 162.76, 154.21, 143.74, 142.95, 138.62, 127.00, 126.52, 124.77, 124.35, 117.31, 83.70, 69.47, 38.83, 27.66, 26.81, 26.34, 25.28, 24.63, 2.34. Anal. Calcd for C35H52N3SiTiCl : C, 67.13; H, 8.37; N, 6.71. Found: C, 67.08; H, 8.44; N, 5.79. (BDMP)Ti(CH2SiMe,)2 (8b). To a diethyl ether (30 mL) suspension of compound 3b (0.100 g, 0.216 mmol) was added 2.2 equiv of LiCH2SiMe3 (0.045 g, 0.476 mmol) at -40 °C. The solution changed from orange to yellow within minutes and was stirred for 12 h. The solvent was removed in vacuo. The resulting solid was extracted with toluene (3 x 10 mL) and filtered through Celite. The solvent was removed in vacuo, the solid dissolved in a minimum References start on page 80 72 amount of hexanes and cooled to -40 °C for 12 h. Yellow crystalline 8b was isolated by filtration and dried under vacuum (0.112 g, 0.198 mmol, 92%). JH NMR 8 7.17 (d, 4H, Ar), 7.03 (m, 2H, Ar), 6.89 (t, IH, py), 6.45 (d, 2H, py), 4.76 (s, 4H, NC7/2), 2.52 (s, 12H, Me), 1.84 (s, 4H, C7/2Si), -0.19 (s, 18H, Si(C//3)3). 13C{'H) NMR 8 162.64, 156.36, 138.17, 134.07, 129.35, 125.29, 117.10, 83.16, 66.23, 19.62, 2.38. (BDMP)Ti(CH2CMe2Ph)Cl (9b). To a diethyl ether (30 mL) suspension of compound 3b (0.400 g, 0.865 mmol) was added 1.1 equiv of PhCMe2CH2MgCl (1.09 mL, 0.867 M, 0.952 mmol) at -40 °C. The solution changed from orange to dark red within minutes and was stirred for 12 h. The solvent was removed in vacuo. The resulting solid was extracted with toluene (3 x 10 mL) and filtered through Celite. The solvent was removed in vacuo, the solid dissolved in a minimum amount of a 20:1 mixture of THF/benzene and cooled to -40 °C for 12 h. Red crystalline 9b was isolated by filtration and dried under vacuum (0.400 g, 0.627 mmol, 72%). 'H NMR 8 7.19-6.98 (m, 11H, Ar and Ph), 6.89 (t, IH, py), 6.39 (d, 2H, py), 4.59 (AB quartet, 2JHH = 21.98 Hz, 4H, NC/72), 2.92 (s, 2H, C//2CMe2), 2.75 (s, 6H, Me), 2.10 (s, 6H, Me), 1.10 (s, 6H, CH2CMe2). ,3C{'H} NMR 8 163.38, 157.73, 152.96, 138.26, 133.36, 132.50, 128.99, 128.87, 125.55, 125.42, 125.22, 117.35, 97.42, 66.33, 46.33, 32.05, 20.67, 18.50. Anal. Calcd for C33H3gN3TiCl*C6H6: C, 73.40; H, 6.95; N, 6.58. Found: C, 73.60; H, 7.26; N, 6.16. (BDMP)Ti(CH2CMe2Ph)Br (10b). To a diethyl ether (30 mL) solution of compound 9b (0.400 g, 0.714 mmol) was added 10 equiv of MgBr2»2Et20 (2.373 g, 7.14 mmol) at room temperature. The solution was stirred for 12 h. The solvent was removed in vacuo. The resulting solid was extracted with toluene (3 x 10 mL) and filtered through Celite. The solvent was removed in vacuo, the solid dissolved in a minimum amount of a 20:1 mixture of THF/benzene and cooled to -40 °C for 12 h. Red crystalline 10b was isolated by'filtration and dried under vacuum (0.356 g, 0.522 mmol, 73%). lU NMR 8 7.19-6.98 (m, 11H, Ar and Ph), 6.86 (t, IH, py), 6.36 (d, 2H, py), 4.59 (AB quartet, 2JHH = 21.98 Hz, 4H, NC//2), 2.95 (s, References start on page 80 73 2H, C#2CMe2), 2.80 (s, 6H, Me), 2.03 (s, 6H, Me), 1.08 (s, 6H, CH2CMe2). 13C{'H} NMR 5 163.36, 158.33, 152.80, 138.22, 133.34, 132.51, 129.03, 128.88, 125.53, 125.51, 125.25, 117.28, 102.03, 66.50, 46.89, 31.96, 20.78, 19.66. Anal. Calcd for CjjHjgNjTiBr-QH,: C, 68.62; H, 6.50; N, 6.16. Found: C, 68.61; H, 6.69; N,. 5.76 (BDPP)Ti(CH2C6H4-o-NMe2)Cl (11a). To a diethyl ether (25 mL) suspension of complex 3a (0.250 g, mmol) was added 1.2 equiv. of Li(CH2C6H4-o-NMe2) (0.074 g, mmol) at -78 °C. The solution changed from yellow to black within minutes and was stirred for 12 h. The solvent was removed in vacuo. The resulting solid was extracted with toluene (3 x 10 mL) and filtered through Celite. Attempt to separate complex 11a from the reaction mixture were unsuccessul. 'H NMR 5 7.29 (dd, 1H, CH2C6//4), 7.22 (t, 2H, Ar), 7.18 (d, 4H, Ar), 6.77 (td, 1H, CH2C6//4), 6.68 (t, 1H, py), 6.63 (td, 1H, CH2C6//4), 6.49 (dd, 1H, CH2C6//4), 6.19 (d, 2H, py), 4.88 (AB quartet, 2JHH = 22.0 Hz, 4H, NCH2), 4.72 (sept, 2H, C//Me2), 3.62 (s, 2H, C//2C6H4), 2.90 (sept, 2H, C//Me2), 2.28 (s, 6H, ~NMe2), 1.65 (d, 6H, CHMe2), 1.49 (d, 6H, CHM<?2), 1.22 (d, 6H, CHMe2), 1.03 (d, 6H, CHM^). (BDMP)Ti(rj5-C5H5)CI (12b). To a diethyl ether (30 mL) suspension of compound 3b (0.100 g, 0.216 mmol) was added 1.3 equiv of NaC5H5»DME (0.049 g, 0.275 mmol) at -40 °C. The solution changed from orange to yellow within minutes and was stirred for 12 h. The solvent was removed in vacuo. The resulting solid was extracted with toluene (3 x 10 mL) and filtered through Celite. The solvent was removed in vacuo, the solid dissolved in a minimum amount of diethyl ether and cooled to -40 °C for 12 h. Orange crystalline 12b was isolated by filtration and dried under vacuum (0.097 g, 0.197 mmol, 77%). 'H NMR 8 7.17-7.00 (m, 7H, Ar and py), 6.50 (d, 2H, py), 6.02 (s, 5H, Cp), 4.47 (AB quartet, 'J^ = 21.83 Hz, 4H, NC//2), 2.44 (s, 6H, Me), 1.80 (s, 6H, Me). ^{'H} NMR 5163.98, 159.76, 136.62, 133.44, 130.99, 129.29, 128.52, 124.53, 119.63 (Cp), 116.15, 69.26, 18.65. (BDPP)Ti(C4Et4) (13a). A toluene (30 mL) solution of compound 3a (0.100 g, 0.174 mmol) and 3-hexyne (0.035 g, 0.426 mmol) was added to an excess of 1% Na/Hg References start on page 80 74 amalgam (0.074 g Na, 3.22 mmol; 7.40 g Hg). The mixture was stirred for 12 h. The solution was decanted from the amalgam and filtered through a medium porosity frit with the aid of Celite. The solvent was removed in vacuo to yield an orange-brown solid. Due to its high solubility, compound 13a was not isolated in crystalline form. 'H NMR 7.25-7.10 (m, 6H, Ar), 6.93 (t, IH, py), 6.48 (d, 2H, py), 5.02 (s, 4H, NC/72), 3.62 (sept, 4H, C//Me2), 2.13 (m, 8H, a,p C//2Me), 1.35 (d, 12H, CHMe2), 1.28 (d, 12H, CHMe2), 0.92 and 0.39 (t, 6H each, a,(3 CH2Me). 13C{'H} NMR 5 229.33 (Ca), 162.35, 154.12, 143.72, 137.97, 124.90, 123.78, 116.65, 68.72 (NC/72), 28.86, 28.37, 28.16, 26.73, 24.49, 24.29, 22.20, 15.96. (BDPP)Ti(C4Pr4) (14a). The preparation of compound 14a is identical to that of compound 13a. Compound 3a (0.250 g, 0.435 mmol), 4-octyne (0.120 g, 1.09 mmol) and excess 1% Na/Hg amalgam (0.30 g Na, 13.0 mmol; 30.0 g Hg) gave dark red 14a (0.213 g, 0.294 mmol, 68%) when recrystallized from diethylether at -30 °C. 'H NMR 7.25-7.10 (m, 6H, Ar), 6.93 (t, IH, py), 6.46 (d, 2H, py), 5.05 (br s, 4H, NC/Y2), 3.64 (br sept, 4H, C/YMe2), 2.21 and 2.11 (m, 8H, a,(3 C//2CH2Me), 1.38 (d, 12H, CHMe2), 1.24 (d, 12H, CHMe2), 0.90 (m, 12H, aj3 CH2CH2Me), 0.71 (br m, 8H, a,f3 CH2C/72Me). 13C{'H} NMR 5 229.33 (Ca), 162.22, 154.06, 143.80, 137.86, 124.94, 123.80, 116.57, 68.69 (NC/72), 68.73, 39.09, 32.35, 28.42, 26.71, 25.05, 24.38, 23.25, 15.24. Anal. Calcd for C47H69N3Ti: C, 77.97 ; H, 9.61; N, 5.80. Found: C, 78.18; H, 9.49; N, 6.20. (BDPP)Ti(C4Ph4) (15a). The preparation of compound 15a is identical to that of complex 13a. Compound 3a (0.500 g, 0.870 mmol), diphenylacetylene (0.310 g, 1.74 mmol) and excess 1% Na/Hg amalgam (0.60 g Na, 26.1 mmol; 60.0 g,Hg) gave red crystalline 15a (0.423 g, 0.620 mmol, 71%) when recrystallized from diethylether at -30 °C. *H NMR (23 °C) 8 7.2-6.1 (br m, Ar, Ph, py), 6.27 (d, 2H, py), 5.56 (br m, 2H, C//2N), 4.95 (br m, 2H, CHMe2), 4.51 (br m, 2H, C/72N), 2.83 (br m, 2H, C/7Me2), 1.87 (br m, 6H,CHMe2), 1.53 (br m, 6H, CWMe2), 0.87 (br m, 12H, CHMe2). 'H NMR (-20 °C, d8-toluene) 5 7.4-6.5 (m, Ar, Ph and py), 6.22 (d, py, 2H), 5.47 (d, 2H, Ph0), 5.03 (AB quartet, 'J^ = 20.63 Hz, 4H, NC/Y2), References start on page 80 75 4.99 (sept, 2H, C//Me2), 2.79 (sept, 2H, C//Me2), 1.93 (d, 6H, CHMe2), 1.62 (d, 6H, CHMe2), 0.91 (d, 6H, CHMe2), 0.82 (d, 6H, CHMe2). 13C{'H} NMR (-40 °C, d8-toluene) 8 161.16, 152.28, 146.88, 138.03, 131.89, 131.60 (br), 131.78, 129.95, 127.27, 126.57, 126.17, 125.74, 124.23 (br), 123.19, 116.59, 69.21, 29.75 (br), 28.40 (br), 27.26 (br), 25.84 (br), 23.75. Anal. Calcd for C59H6IN3Ti: C, 82.40; H, 7.15; N, 4.89. Found: C, 82.37; H, 7.21; N, 5.13. (BDMP)Ti(C4Ph4) (15b). The preparation of compound 15b is identical to that of compound 13a. Compound 3b (0.500 g, 1.08 mmol), diphenylacetylene (0.482 g, 2.70 mmol) and excess 1% Na/Hg (0.25 g Na, 10.9 mmol; 24.9 g Hg) gave red crystalline 15b (0.497 g, 0.665 mmol, 62%) when recrystallized from diethylether at -30 °C. 'H NMR 8 7.21 (d, 4H, Ar), 7.08 (t, 2H, Ar), 6.92 (m, 4H, Ph), 6.76 (m, 8H, Ph), 6.66 (m, 5H, Ph and py), 6.34 (d, 2H, py), 5.96 (m, 4H, Ph), 4.71 (s, 4H, Ctf2N), 2.52 (s, 12H, Me). I3C {'H} NMR 8 221.66 (Ca), 161.72, 153.74, 146.02, 143.66, 140.22, 137.99, 134.07, 131.91, 130.48, 129.25, 127.08, 126.98, 125.80, 125.36, 123.31, 116.88, 66.16 (NC//2), 19.24. (BDPP)Ti[a,p'-C4H2(SiMe3)2] (16a). The preparation of compound 16a is identical to that of compound 13a. Compound 3a (0.200 g, 0.348 mmol), Me3SiC^CH (0.088 g, 0.696 mmol) and excess 1% Na/Hg amalgam (0.240 g Na, 10.4 mmol; 24.0 g Hg) gave yellow crystalline 16a (0.157 g, 0.224 mmol, 64%) when recrystallized from pentane at -30 °C. 'H NMR 8 8.68, 8.66 (s, 1H each, cx,P'-Ctf), 7.15-7.05 (m, 6H, Ar), 6.95 (t, 1H, py), 6.53 (d, 2H, py), 4.92 (AB quartet, 2JHH = 21.15 Hz, 4H, NC//2), 3.66 (sept, 2H, C//Me2), 3.46 (sept, 2H, CHMc2), 1.43 (d, 6H, CHMe2), 1.28 (d, 6H, CHMe2), 1.24 (d, 6H, CHMe2), 1.15 (d, 6H, CHMe2), 0.04 and -0.15 (s, 9H each, a,p'-SiMe3). 13C{'H} NMR 8 218.81 (a-CH), 215.04 (a-CSiMe3), 163.12, 153.33, 144.06, 142.71, 138.14 (P-CH), 137.63, 128.59, 124.94, 124.20, 123.64, 117.25, 67.35, 28.72, 27.10, 26.65, 26.41, 24.87, 23.78, -0.38, -1.86. Anal. Calcd for C4IH61N3Si2Ti: C, 70.35; H, 8.78; N, 6.00. Found: C, 69.97; H, 8.94; N, 6.02. References start on page 80 76 (BDMP)Ti[a,a'-C4H2(SiMe,)2] (16b). The preparation of compound 16b is identical to that of compound 13a. Compound 3b (0.100 g, 0.216 mmol), Me3SiC=CH (0.047 g, 0.476 mmol) and excess Na/Hg amalgam (0.074 g Na, 3.22 mmol; 7.40 g Hg) gave yellow crystalline 16b (0.431 g, 0.609 mmol, 70%) when recrystallized from pentane at -30 °C. 'H NMR 5 8.50 (s, 2H, p,p'-C/7), 7.03 (d, 4H, Ar), 6.94 (t, IH, py), 6.91 (m, 2H, Ar), 6.55 (d, 2H, py), 4.59 (s, 4H, NC/72), 2.27 (s, 12H, Me), -0.23 (s, 18H, oca'-SiMe,). 13C{'H} NMR 8 228.41 (CSiMe3), 163.15, 156.02, 138.25, 133.72, 132.26, 124.70, 117.43, 65.45, 20.10, -0.28. Anal. Calcd for C33H45N3Si2Ti: C, 67.43; H, 7.72; N, 7.15. Found: C, 67.83; H, 7.93; N, 7.29. (BDPP)Ti[oc,P'-C4H2Ph2] (17a). The preparation of compound 17a is identical to that of compound 13a. Compound 3a (0.500 g, 0.870 mmol), phenylacetylene (0.267 g, 2.61 mmol) and excess Na/Hg amalgam (0.60 g Na, 26.0 mmol; 60.0 g Hg) gave dark-red crystalline 17a (0.431 g, 0.609 mmol, 70%) when isolated from diethylether at -30 °C. 'H NMR 8 7.45 (s, 2H, p,p'-C//), 7.21 (m, 6H, Ar), 7.00 (t, 4H, Ph), 6.89 (m, 3H, Ph and py), 6.41 (d, 2H, py), 6.18 (d, 4H, Ph), 4.99 (s, 4H, NC/72), 2.65 (sept, 4H, C/YMe2), 1.18 (d, 12H, CUMe2), 1.20 (d, 12H, CHMe2). 13C {'H} NMR 8 220.77 (a-CPh), 161.88, 153.74, 148.02 (p-CH), 143.50, 138.18, 125.65, 125.39, 125.25, 124.46, 124.16, 117.23, 68.32, 28.04, 26.70, 23.37. Anal. Calcd for C47H53N,Ti : C, 79.75; H, 7.55; N, 5.94. Found: C, 79.35; H, 7.91; N, 5.99. (BDMP)Ti[C4oc-(SiMe3)Et2H] (18b). A benzene (5 mL) solution containing complex 16b (0.025 g, 0.043 mmol) and 3-hexyne (0.030 g, 0.365 mmol) was heated to 80 °C for 12 h. The solvent was removed in vacuo and the sample dissolved in C6D6. Quantitative yield by 'H NMR spectroscopy. 'H NMR 8 8.23 (s, IH, P'-C/V), 7.05-6.95 (m, 5H, Ar and py), 6.88 (t, 2H, Ar), 6.55 (d, 2H, py), 4.65 (AB quartet, 2JHH = 21.1 Hz, C/V2N), 2.28 (s, 12H, Me), 2.14 and 1.89 (q, 2H each, C/V2Me), 0.87 and 0.27 (t, 3H each, CH2Me), -0.08 (s, 9H, References start on page 80 77 SiMe3). 13C{'H} NMR 5 228.35, 221.93, 162.96, 155.30, 137.74, 135.44, 134.60, 134.00, 132.73, 123.88, 117.01, 64.99, 31.87, 27.82, 19.84, 19.11, 12.80, 12.63, -0.38. (BDMP)Ti[C4a-(SiMe3)Pr2H] (19b). A benzene (5 mL) solution containing complex 16b (0.025 g, 0.043 mmol) and 4-octyne (0.030 g, 0.272 mmol) was heated to 80 °C for 12 h. The solvent was removed in vacuo and the sample dissolved in C6D6. Quantitative yield by ]H NMR spectroscopy. :H NMR 8 8.29 (s, 1H, p'-Ctf), 7.10-6.95 (m, 5H, Ar and py), 6.90 (t, 2H, Ar), 6.57 (d, 2H, py), 4.66 (AB quartet, 'J^ = 21.1 Hz, CH2N), 2.30 (s, 12H, Me), 2.8 and 1.85 (m, 2H each, C//2CH2Me, 1.38 (m, 2H, CH2C//2Me), 0.82 and 0.70 (t, 3 each, CH2CH2Me), 0.58 (m, 2H, CH2C#2Me), -0.07 (s, 9H, SiM<?3). 13C{'H} NMR 8 228.64, 221.78, 162.95, 155.36, 137.78, 134.66, 133.90, 132.84, 129.25, 127.24, 127.04, 124.76, 123.95, 122.24, 120.20, 117.03, 65.18,41.40, 37.94, 22.04, 21.64, 19.86, 19.08, 15.28, 14.68, -0.34. Activated ligand complex (20b). A THF (30 mL) solution of compound 3b (0.500 g, 1.08 mmol) and 1-phenylpropyne (0.314 g, 2.70 mmol) were added to an excess of Mg (0.250 g, 10.3 mmol). The mixture was stirred for 12 h. The solution was decanted from the magnesium and filtered through Celite. The solvent was removed in vacuo to yield an dark brown solid. The solid was dissolved in a minimum amount of diethylether and cooled to -30 °C for 12 h. Dark red crystalline 20b was isolated by filtration and dried under vacuum (0.371 g, 0.595 mmol, 55%). 'H NMR 8 7.20-6.80 (m, 15H, Ph, Ar and py), 6.63 and 6.41 (d, 1H each, py), 6.19 (m, 2H, Ph), 4.96 (AB quartet, 'J^, = 21.3 Hz, 2H, C//2N), 4.71 (AB quartet, 'J^ = 19.9 Hz, 2H C//2N), 3.65 (q, 1H, C=C#Me), 3.13 (m, 2H), 2.78 (m, 2H), 2.40 (s, 3H, ArMe), 1.97 (d, 3H, C=CHMe), 1.85 (m, 1H), 1.82 (s, 3H, ArMe), 0.94 (s, 3H, ArMe). 13C{'H} 5 166.32, 162.63, 154.66, 148.25, 147.98, 142.48, 141.40, 140.49, 137.30, 136.85, 135.47, 131.20, 129.01, 128.73, 127.44, 147.21, 126.93, 126.82, 126.53, 126.00, 122.62, 121.81, 120.62, 117.51, 117.09, 84.78, 71.57, 69.09, 67.55, 64.73, 39.54, 21.64, 18.10, 17.47, 15.96. References start on page 80 78 (BDPP)Ti(C4H6) (21a). To a diethyl ether (30 mL) suspension of compound 3a (0.100 g, 0.216 mmol) was added 1.3 equiv of Mg(C4H6) • 2THF (0.062 g, 0.279 mmol) at -40 °C. The solution changed from orange to black within minutes and was stirred for 12 h. The solvent was removed in vacuo. The resulting solid was extracted with toluene (3 x 10 mL) and filtered through Celite. The solvent was removed in vacuo to give a black oily solid (0.058 g, 0.104 mmol, 48 %). The high solubility of complex 21b prevented its isolation from the reaction mixture. 'H NMR 6 7.17-7.00 (m, 7H, Ar and py), 6.65 (d, 2H, py), 5.28 (m, 2H, C4H6), 5.19 (s, 2H, NCffj), 4.98 (s, 2H, NC/Y2), 3.80 (sept, 2H, CHMe2), 3.61 (m, 2H, C4H6), 2.78 (sept, 2H, CHMe2), 1.38 (d, 6H, CHM^2), 1.21 (d, 6H, CHMe2), 1.18 (d, 6H, CHMe2), 1.00 (d, 6H, CHMe2). The remaining butadiene resonance is undiscernable from the resonances due to impurities. (BDPP)Ti+{C(SiMe3)=CHC(SiMe3)=CHB {C6F5}3 (22a). To a pentane solution (5 mL) of B(C6F5)3 (0.073 g, 0.143 mmol) was added a pentane solution (5 mL) of complex 16a (0.100 g, 0.143 mmol) at -30°C. The solution was stirred for 30 minutes and the solvent removed in vacuo. The yellow oily solid (22a) was then dissolved in C6D6 and characterized by 'H NMR spectroscopy. 'H NMR 5 9.29 (m, IH, C/7B), 8.07 (s, 2H, CHC), 7.52 (d, 2H, py), 7.48 (t, IH, py), 6.97 (m, 4H, Ar), 6.79 (m, 2H, Ar), 4.88 (AB quartet, zJm = 21.0 Hz, 4H, NC//2), 3.12 (sept, IH, C/YMe2), 2.49 (sept, IH, C//Me2), 2.37 (sept, IH, C//Me2), 1.81 (sept, IH, CJ7Me2), 1.39 (d, 3H, CHMe2), 1.13 (d, 3H, CHMe2), 1.11 (d, 3H, CHMe2), 0.98 (d, 3H, CUMe2), 0.86 (d, 3H, CHMe2), 0.85 (d, 3H, CHMe2), 0.82 (d, 3H, CHMe2), 0.74 (d, 3H, CRMe2), -0.12 (s, 9H, SiMe,), -0.48 (s, 9H, SiMe3). X-ray Crystallographic Analysis of complex 10b. A suitable crystal of 10b was grown from a saturated THF/benzene solution at room temperature. Complete crystal data may be found in the appendix. Data were collected on a Enraf-Nonius CAD4F diffractometer using CAD4F software * '0. Intensity data were recorded in co-20 scan mode at variable scan speeds within a maximum time per datum of 45s. Moving background estimates were made at 25% scan extensions on each side. Standard reflections were monitored every 180 min of X-ray References start on page 80 79 exposure time. Lorentz, polarization and decay corrections were applied. Crystal faces were identified by optical goniometry, and a Gaussian absorption correction made to the data, which were averaged to yield 6115 unique data for structure solution and refinement. The structure was solved by a combination of SHELXS and difference Fourier syntheses using SHELXL-93 software m. Anisotropic thermal parameters were refined for all non-hydrogen atoms. All phenyl hydrogen atoms were located by difference Fourier methods, placed in calculated positions (C-H = 0.9A), and included in the structure factor calculations. The four methyl groups C(27), C(28), C(37), and C(38) showed disorder. The idealized tetrahedral groups were assigned 0.5 multiplicities. The benzene solvent molecule showed considerable thermal motion, but refined well to an acceptable geometry. X-ray Crystallographic Analysis of complex 16a. A suitable crystal of 16a was grown from a saturated hexane solution at -30 °C. Complete crystal data may be found in appendix. A preliminary investigation showed that the crystals were weakly diffracting. Data were collected on a Siemans P4 diffractometer with the XSCANS software package.^2 The Laue symmetry 2/m was determined by merging symmetry equiv positions. A total of 6646 data were collected in the range of 6 = 1.9-22.0° (-l<h<ll, -l<k<38, -12<1<12). Three standard reflections monitored at the end of every 297 reflections collected showed no decay of the crystal. In the shell 38<20<44° only 3% of the reflections were found to be significant. The data processing, solution and refinement were done using SHELXTL-PC programs. * ^ The methyl carbons attached to Si(2) were found to have two different orientations with occupancies of 0.6 and 0.4. Similarly, the two methyl carbon atoms of the isopropyl group attached to C(27) were found to occupy two positions (occupancy 0.5 and 0.5). Common isotropic thermal parameters were refined for these disordered carbon atoms. An empirical absorption correction was applied to the data using the \|/ scans data. No attempt was made to locate hydrogen atoms and were placed in calculated positions. The phenyl groups were constrained to be regular hexagons with C-C distances of 1.395A. In the final difference Fourier synthesis the electron density fluctuates in the range 0.385 to -0.346 e A?. References start on page 80 80 5 References (1) Lappert, M. F.; Power, P. P.; Sanger, A. R.; Srivastava, R. C. Metal and Metalloid amides: Synthesis, Structures and Physical and Chemical Properties; John Wiley & Sons: Chichester, 1980. (2) Burger, H.; Neese, H.-J. Chimia 1970, 35, 209. (3) Bradley, D. C; Chisholm, M. H. Acc. Chem. Res. 1976, 9, 273. (4) Kornicker, W. A. U.S. Patent 3,318,932 1967. (5) Alyea, E. C; Bradley, D. C; Lappert, M. F.; Sanger, A. R. J. Chem. Soc, Chem. Commun. 1969, 1064. (6) Lappert, M. F.; Sanger, A. R. J. Chem. Soc (A) 1971, 874. (7) Alyea, E. C; Bradley, D. C. J. Chem. Soc (A) 1969, 2330. (8) Alyea, E. C; Bradley, D. C; Copperthwaite, R. G. J. Chem, Soc, Dalton Trans. 1972, 1580. (9) Lappert, M. F.; Sanger, A. R. J. Chem, Soc (A) 1971, 1314. (10) Chien, J. C. W.; Kruse, W. Inorg. Chem. 1970, 9, 2615. (11) Bradley, D. C; Copperthwaite, R. G. J. Chem. Soc, Chem. Commun. 1971, 764. (12) Alyea, E. C; Bradley, D. C; Copperthwaite, R. G. J. Chem. Soc, Dalton Trans. 1973, 185. (13) Alyea, E. C; Bradley, D. C; Copperthwaite, R. G. J. Chem, Soc, Dalton Trans. 1972, 1580. (14) Canich, J. A. ; Canich, J. A., Ed., European Patent Application EP-420-436-A1; Vol. April 4, 1991. (15) Canich, J. A.; Turner, H. W. ; Canich, J. A.; Turner, H. W., Ed., W. PCT Int. Appl. WO 92/12162; fding date December 26, 1991. (16) Stevens, J. C; Timmers, F. J.; Wilson, D. R.; Schmidt, G. F.; Nickias, P. N.; Rosen, R. K.; Knight, G. W.; Lai, S. Y. ; Stevens, J. C; Timmers, F. J.; Wilson, D. R.; Schmidt, G. F.; References start on page 80 81 Nickias, P. N.; Rosen, R. K.; Knight, G. W.; Lai, S. Y., Ed., European Patent Application EP-416-815-A2; March 13, 1991. (17) Bradley, D. C.; Gitlitz, M. H. J. Chem. Soc. (A) 1969, 980. (18) Burger, H.; Kluess, C; Neese, H.-J. Z. Anorg. Chem 1971, 381, 198. (19) Gibbins, S. G.; Lappert, M. F.; Pedley, J. B.; Sharp, G. J. J. Chem. Soc, Dalton Trans. 1975, 72. . (20) Bradley, D. C.; Gitlitz, M. H. J. Chem. Soc. (A) 1969, 1152. (21) Bradley, D. C; Gitlitz, M. H. J. Chem, Soc, Chem. Commun. 1965, 289. (22) Airoldi, C; Bradley, D. C. Inorg. Nucl. Chem. Letters 1975,11, 155. (23) Dermer, D. C; Fernelius, W. C. Z Anorg. Chem, 1935, 227, 83. (24) Bradley, D. C; Thomas, I. M. J. Chem. Soc. 1960, 3857. (25) Chandra, G.; Lappert, M. F. Inorg. Nucl. Chem,, Letters 1965,1, 83. (26) Chandra, G.; Lappert, M. F. J. Chem. Soc. (A) 1968, 1940. (27) Burger, H.; Kluess, C. J. Organomet. Chem. 1976,108, 69. (28) Burger, FL; Neese, H.-J. Z Anorg. Chem. 1969, 365, 243. (29) Benzing, E. P.; Kornicker, W. A. Chem. Ber. 1961, 94, 2263. (30) Scoles, L.; Minhas, R.; Duchateau, R.; Jubb, J.; Gambarotta, S. Organometallics 1994, 13, 4978. (31) Ott, K. C; Grubbs, R. H. J. Am. Chem. Soc 1981,103, 5922. (32) Meinhart, J. D.; Anslyn, E. V.; Grubbs, R. H. Organometallics 1989, 8, 583. (33) Brauer, D. J.; Burger, H.; Weigel, K. J. Organomet. Chem. 1978,150, 215. (34) Burger, H.; Dammgen, U. Z Anorg. Chem. 1977, 429, 173. (35) Burger, H.; Weigel, K. J. Organomet. Chem. 1977,124, 279. (36) Bradley, D. C; Torrible, E. G. Can. J. Chem. 1962, 41, 134. (37) Jones, R. A.; Seeberger, M. H.; Atwood, J. L.; Hunter, W. E. J. Organomet. Chem. 1983, 247, 1. References start on page 80 82 (38) Warren, T. H.; Schrock, R. R.; Davis, W. M. Organometallics 1996,15, 562. (39) Fuhrmann, H.; Bernner, S.; Arndt, P.; Kempe, R. Inorg. Chem. 1996, 35, 6742. (40) Friedrich, S.; Gade, L. H.; Edwards, A. J.; McPartlin, M. J. Chem. Soc, Dalton Trans. 1993, 2861. (41) Schubart, M.; O'Dwyer, L.; Gade, L. H.; Li, W.-S.; McPartlin, M. Inorg. Chem. 1994, 33, 3893. (42) Hubert, A. J.; Dale, J. J. Chem. Soc. 1965, 3160. (43) Hill, J. E.; Balaich, G.; Fanwick, P. E.; Rothwell, I. P. Organometallics 1993,12, 2911. (44) Takahashi, T.; Kotora, M.; Xi, Z. J. Chem, Soc, Chem. Commun. 1995, 361. (45) van der Linden, A.; Schaverien, C. J.; Meijboom, N.; Ganter, C; Orpen, A. G. J. Am. Chem. Soc. 1995,117, 3008. (46) Williams, A. C; Sheffels, P.; Sheenan, D.; Livinghouse, T. Organometallics 1989, 8, 1566. (47) Masuda, T.; Deng, Y.-X.; Higashimura, T. Bull Chem. Soc. Jpn. 1983, 56, 2798. (48) Masuda, T.; Deng, Y.-X.; Higashimura, T. Bull. Chem, Soc. Jpn. 1980, 53, 1152. (49) Cotton, F. A.; Hall, W. T.; Cann, K. J.; Karol, F. J. Macromolecules 1981,14, 233. (50) Strickler, J. R.; Bruck, M. A.; Wigley, D. E. J. Am, Chem, Soc 1990,112, 2814. (51) Gambarotta, S.; Wielstra, Y.; Meetsma, A.; Boer, J. L. d. Organometallics 1989,11, 1275. (52) Smith, D. P.; Strickler, J. R.; Gray, S. D.; Bruck, M. A.; Holmes, R. S.; Wigley, D. E. Organometallics 1992,11, 1275. (53) McDonald, F. E.; Zhu, H. Y. H.; Holmquist, C. R. J. Am. Chem, Soc. 1995,117, 6605. (54) Taber, D. F.; Rahimizadeg, M. Tetrahedron Lett. 1994, 35, 9139. (55) Yokota, T.; Sakurai, Y.; Skaguchi, S.; Ishii, Y. Tetrahedron Lett, 1997, 38(22), 3923. (56) Jhingan, A. K.; Maier, W. F. J. Org. Chem, 1987, 52, 1161. (57) Tyler, D. R.; Mao, F.; Shut, D. M. Organometallics 1996,15, 4770. (58) Bianchini, COrganometallics 1994,13, 2010. References start on page 80 83 (59) Calderazzo, F.; Marchetti, F.; Pampaloni, G.; Hiller, W.; Antropiusova, H.; Mach, K. Chem. Ber. 1989, 722, 2229. (60) Canziani, F.; Allevi, C.; Garlaschelli, L.; Malatesta, M. C.; Albinati, A.; Ganazolli, F. J. Chem. Soc, Dalton Trans. 1984, 2637. (61) Chiusoli, G. P.; Pallini, L.; Terenchi, G. Trans. Met. Chem. 1983, 8, 189. (62) Collman, J. P.; Kang, J. W.; Little, W. F.; Sullivan, M. F. Inorg. Chem. 1968, 7, 1298. (63) Cotton, F. A.; Hall, W. T.; Cann, K. J.; Karol, F. J. Macromolecules 1981,14, 233. (64) Grigg, R.; Scott, R.; Stevenson, P. Tetrahedron Lett. 1982, 23, 2691. (65) Halterman, R. L.; Nguyen, N. H.; Vollhardt, K. P. C. J. Am. Chem. Soc. 1985, 707, 1379. (66) Jhingan, A. K.; Maier, W. F. J. Org. Chem. 1987, 52, 1161. (67) Lachmann, G.; DuPlessis, J. A. K.; DuTort, C. J. J. Mol, Catal, 1987, 42, 151. (68) Maitlis, P. M. J. Organomet. Chem. 1980, 200, 161. (69) Mantovani, A.; Marcomini, A.; Belluco, U. J. Mol, Catal. 1985, 30, 73. (70) McAlister, D. R.; Bercaw, J. E.; Bergman, R. G. J. Am. Chem. Soc. 1977, 99, 1666. (71) Schonfelder, W.; Snatzke, G. Chem. Ber. 1980, 775, 1855. (72) Shore, N. E. Chem, Rev. 1988, 88, 1081. (73) Ville, G. A.; Vollhardt, K. P. C; Winter, M. J. Organometallics 1984, 3, 1177. (74) Vollhardt, K. P. C. Angew. Chem., Int. Ed. Engl. 1984, 23, 539. (75) Winter, M. J., Mechanism of cyclotrimerization; Winter, M. J., Ed.; Wiley: Chichester, U.K., 1985; Vol. 3, pp Chapter 5. (76) Strickler, J. R.; Wexler, P. A.; Wigley, D. E. Organometallics 1988, 2067. (77) Bianchini, C; Caulton, K. G.; Chardon, C; Eisenstein, O.; Folting, K.; Johnson, T. J.; Meli, A.; Peruzzini, M.; Rauscher, D. J.; Streib, W. E.; Vizza, F. J. Am. Chem Soc. 1991, 773, 5127. (78) Labinger, J. A.; Schwartz, J.; Townsend, T. M. J. Am. Chem. Soc. 1974, 96, 4009. References start on page 80 84 (79) Green, M. L. H.; Jousseaume, B. J. Organomet. Chem. 1980,193, 339. (80) Gibson, V. C; Parkin, G.; Bercaw, J. Organometallics 1991,10, 220. (8.1) Chao, Y.-W.; Wexler, P. A.; Wigley, D. E. Inorg. Chem. 1989, 28, 3860. (82) Bruck, M. A.; Copenhaver, A. S.; Wigley, D. E. J. Am Chem. Soc. 1987,109, 6525. (83) Strickler, J. R.; Wexler, P. A.; Wigley, D. E. Organometallics 1991,10, 118. (84) Sikora, D. J.; Rausch, M. D. J. Organomet. Chem. 1984, 276, 21. (85) Famili, A.; Farona, M. F.; Thanedar, S. J. Chem. Soc, Chem. Commun. 1983, 435. (86) Haeg, M. E.; Whitlock, B. J.; Whitlock Jr., H. W. J. Am. Chem. Soc 1989, 111, 692. (87) Evans, D. F.; Fazakerley, G. V.; Phillips, R. F. J. Chem. Soc. (A) 1971, 1931. (88) . (89) Collier, M. R.; Lappert, M. F.; Pierce, R. J. Chem. Soc, Dalton Trans. 1973, 445. (90) Zucchini, U.; Albizatti, E.; Giannini, U. J. Organomet, Chem. 1971, 26, 357. (91) Thiele, K. H.; Kohler, E.; Adler, B. J. Organomet. Chem. 1973, 50, 153. (92) Fujita, K.; Ohnuma, Y.; Yasuda, FL; Tani, H. J. Organomet. Chem, 1976,113, 201. (93) Rosen, R. K. Addition polymerization catalysts comprising reduced oxidation state metal complexes; Rosen, R. K., Ed.; (DOW) US Patent WO 93/19104 PCT/US93/02584, 1993. (94) Herrmann, W. A.; Denk, M; Albach, R. W.; Behm, J.; Herdtweck, E. Chem. Ber. 1991, 124, 683. (95) Cummins, C. C; Schrock, R. R.; Davis, W. M. Organometallics 1992,11, 1452. (96) Aoyagi, K.; Gantzel, P. K.; Kalai, K.; Tilley, T. D. Organometallics 1996,15, 923. (97) Clark, H. C. S.; Cloke, F. G. N.; Hitchcock, P. B.; Love, J. B.; Wainwright, A. P. J. Organomet. Chem, 1995, 501, 333. (98) Alt, H. G.; Englehardt, H. E.; Rausch, M. D.; Kool, L. B. J. Am, Chem. Soc. 1985, 707, 3717. (99) Hill, J. E.; Fanwick, P. E.; Rothwell, I. P. Organometallics 1990, 9, 2211. References start on page 80 85 (100) McCLure, NMR Spectroscopy Techniques; Second Edition, Revised and Expanded ed.; Marcel Dekker Inc.: New York, 1996; Vol. 21, pp 269. (101) Atwood, J. L.; Hunter, W. E.; Alt, H.; Rausch, M. D. J. Am. Chem. Soc. 1976, 98, 2454. (102) Silverstein, R. M.; Bassler, G. C; Morrill, T. C, Spectrometric Identification of Organic Compounds; Fourth ed.; Silverstein, R. M.; Bassler, G. C; Morrill, T. C, Ed.; John Wiley & Sons: New York, 1981, pp 235. (103) Eisch, J. J.; Piotrowski, A. M.; Brownstein, S. K.; Gabe, E. J.; Lee, F. L. J. Am. Chem. Soc. 1985,107, 7219. (104) Ruwwe, J.; Erker, G.; Frohlich, R. Angew. Chem., Int. Ed. Engl. 1996, 35(1), 80. (105) Hill, J. E.; Fanwick, P.; Rothwell, I. P. Organometallics 1991,10, 15. (106) Kennepohl, D. K.; Brooker, S.; Sheldrick, G. M.; Roesky, H. W. Chem. Ber. 1991, 124, 2223. (107) Schrock, R. R.; Fellmann, J. D. J. Am. Chem. Soc. 1978,100, 3359. (108) Manzer, L. E. J. Am. Chem. Soc. 1978,100, 8068. (109) Smart, J. C; Curtis, C. J. Inorganic Chemistry 1977, 16, 1788. (110) Enraf-Nonius Enraf-Nonius Data Collection Package; V5.0 ed.; Enraf-Nonius, Ed.; Enraf-Nonius: Delft, The Netherlands, 1984. (111) Sheldrick, G. M. SHELXL-93; Sheldrick, G. M., Ed.; Institute fuer Anorg. Chemie: Goettingen, Germany, 1993. (112) XSCANS; Siemens Analytical X-Ray Instruments Inc.: Madison, 1990. (113) Sheldrick, G. M. SHELXTL-PC; V4.1 ed.; Sheldrick, G. M., Ed.; Siemens Analytical X-Ray Instruments Inc.: Madison, WI, U.S.A., 1990. References start on page 80 86 "When you sit with a nice girl for two hours, you think it's only a minute. But when you sit on a hot stove for a minute, you think it's two hours. That's relativity!" Albert Einstein 87 Chapter Two. Zirconium Complexes 1 Introduction 1.1 Generalities of zirconium amide complexes Amide complexes of Zr™ are prepared by similar methods to those used for Ti™. Homolepdc {i.e., Zr(NR2)4: R = Me1"4, Et1"4, Pr3, 'Pr5, Bu3, (Bu3] and heteroleptic {i.e., Cp2Zr(NR2)2: R = Me6'7, Et6; LZr(NR2)3: L = Cp6, R = Me; L = Ind6, R = Me; L = CI8, Me9, R = SiMe3} amide complexes of zirconium are known. Chelating diamide complexes of Zr™ have also been reported (Figure 2- 1)10,11. \ = \ \ N — SiMe2 Me2 : N — SiMe2 N —QiMo CI/' / V Y^Si-N„„ / Ri,„ / S,Me2 N — SiMe2 Me2 I N — SiMe2 N —SiMe2 / / / Y = NMe, O, CH2 R = CI, Br, Me Figure 2- 1. Chelating diamide complexes ofZ^ 1.2 Ziegler-Natta olefin polymerization Karl Ziegler was the first to report the polymerization of ethylene at ambient pressure using the TiCl4/AlEt3 catalyst system 12,13 ^t about the same period, Giulio Natta reported the discovery of the stereoselective polymerization of a-olefinsl4"!6. These systems are, however, heterogeneous and the active species is believed to be a neutral Tim or cationic Ti™ complex. The proposed mechanism involves the insertion of a C=C molecule into a metal-alkyl bond. References on page 191 88 The desire to elucidate the mechanism of heterogeneous polymerization catalysts led to metallocene-catalyzed olefin polymerization. Cyclopentadienyl based systems such as Cp2TiPh2, Cp2ZrPh2 or Cp2ZrCl217-20 were used as models for Ziegler-Natta catalysis. R \ CH. 2' 14 Empty coordination -Ti-CH2 II CH2 site R H2C R 1 C H2 CH2 Tu CH2 l c~ 1 CH2 Figure 2- 2. Cossee-Arlman ethylene polymerization mechanism Around 1986, the tetraphenylborate salts of cations such as Cp2ZrMe(THF)+ and Cp2Zr(CH2Ph)(THF)+ (Figure 2- 3) were isolated and their ability to polymerize ethylene without addition of any activator demonstrated21 "31. These and related findings in other groups32~43 lent general acceptance to the proposal that (alkyl)metallocene cations are key intermediates in homogeneous polymerization catalysis. Zr \ ^0 BPh, R Figure 2- 3. Cationic Cp:ZrR References on page 190 89 The study of simple metallocenes led the way to homogeneous catalysts suitable for the polymerization of propylene and higher a-olefins44. Following this discovery, chiral metallocene catalysts capable of polymerizing a-olefins in a stereoregular fashion were reported {i.e. rac-ethylenebis(ri5-indenyl)TiCl2 (Figure 2- 4, a), rac-ethylenebis^^tetrahydroindeny^TiCLj (Figure 2- 4, b)45-53 and rac-dimethylsilylbis(r|5-indenyl)TiMe2 (Figure 2- 4, c)^4,55j When activated with MAO, these ingeniously designed <mKj-metallocenesa catalysts polymerize propylene and other a-olefins to give highly isotactic polymers4°\57,58. a b c Figure 2- 4. Some bridged metallocene complexes The structures of the metallocene and the polymers are in accord with chain migratory insertion being the predominant mechanism of chain growth and with stereochemical control being provided by an asymmetric cationic mono(alkyl) species (Figure 2- 5). An unbridged chiral zirconocene, (l-methyliiuorenyl)2ZrCl2, that produces isotactic polypropylene was recently described59-61 As a result of strong steric interactions between the two fluorenyl ligands, mutual rotation is hindered and the enantiomers of this complex do not interconvert during the growth of the polymer chain. * The prefix ansa (lat. ansa = bent, handle), first used for compounds with an alkane bridge across an arene ring, was adopted as a short notation for metallocene derivatives with an interannular bridge^. References on page 190 90 By: bridging group Figure 2- 5. Isospecific catalysts, alternating handedness polymerization The unbridged zirconocene-based catalyst (2-phenylindenyl)2ZiCL/MAO yields a highly stretchable atactic-isotactic stereoblock polypropylene"2. As a result of restricted rotation about the Zr-indenyl (centroid) bond, the complex appears to isomerize between chiral and achiral coordination geometries during chain growth. The chiral-like complex generates isotactic polypropylene while the achiral-like species affords atactic polypropylene (Figure 2- 6). isotactic block atactic block Atactic Figure 2- 6. Waymouth's catalyst, bis(2-phenyl-indenyl)ZrCl2 The relationship between catalyst structure and stereoselectivity was elegantly delineated in a series of studies on Me2C-bridged fluorenyl complexes (Figure 2- 7). For example the Cs-symmetric complex Me2C(Cp)(9-fluorenyl)-ZrCl2 produces highly syndiotactic polypropylene in the presence of MA063-65 This particular tacticity arises from alternating enantiofacial References on page 190 91 orientation of subsequent olefin insertions. The two coordination sites in this (^-symmetric complex are no longer homotopic, as in a complex with C2 -symmetry, but enantiotopic66. MAO syndiotactic hemiisotactic isotactic Figure 2- 7. Relationship between catalyst structure and stereoselectivity A new stereoisomer of polypropylene is formed with MAO-activated Me2C(2-MeC5H3)-(9-fluorenyl)ZrCl267. This catalyst, with one coordination site blocked by one P-substituent and one by two p-substituents (Figure 2- 7), produces hemiisotactic polypropylene. In this type of polypropylene, every other repeat unit is of identical configuration while the remaining units are randomly configurated. Isotactic polypropylene is obtained when one of the coordination sites in the catalyst Me2C(2-'BuC5H3)-(9-fluorenyl)ZrCl2/MAO is blocked with a rerf-butyl group68. The copolymerization characteristics of metallocene-based catalysts vary with the metallocene complex used69,70 However, in most cases the incorporation of oc-olefins remains low. Recently, catalysts that contain a dimethylsilyl-bridged amidocyclopentadienyl ligand have been synthesized71-74 (Figure 2- 8). These catalysis yield ethylene/oc-olefin copolymers with a high degree of cc-olefin incorporation including long-chain branching. In contrast, metallocene-References on page 190 92 based catalysts only afford linear polyethylene with a low degree of oc-olefin insertion. A related dimethylsilylene-linked amido-fluorenyl ligand has also been prepared7^. Me2Si U Me2SL / ^Cl I f-Bu M = Ti, Zr, Hf Figure 2- 8. Linked Cp-amide complexes Finally, complexes that do not incorporate a cyclopentadienyl ligand have been reported. For example, a series of titanium and zirconium complexes bearing sterically hindered chelating binaphtolates and biphenolates have been synthesized and used for the polymerization of a-olefins (Figure 2- 9)76. This class of L2MC12 systems can be regarded as being analogous to the well-documented group IV metallocenes. These complexes in the presence of MAO are active for the polymerization of a-olefins. As a result of the chiral structure, stereoregular polymerization of 1-hexene is observed and high molecular weight isotactic polyhexene is obtained. .SiMe3 C6H4,4-Ph Ti(CH2Ph)2 C6H4,4-Ph (I) M = Ti, Zr X = CI, Me, CH2Ph (H) Figure 2- 9. Non-Cp metal complexes References on page 190 93 2 Results and Discussion 2.1 2,6-disubstituted and 2,4-6-trisubstituted aryl diamido complexes As described in chapter one, the reaction of two equivalents of LiNHR (R = 2,6-diisopropylphenyl, 2,6-diethylphenyl, 2,6-dimethylphenyl, 2,4,6-trichlorophenyl or 2,4,6-tribromophenyl) with 2,6-bis(bromomethyl)pyridine77 yields the diamine (BDPP)H2 (la), (BDEP)H2 (lb), (BDMP)H2 (lc), (TCPP)H2 (Id) or (TBPP)H2 (le) (eq. 1). Compounds la,d,e can be isolated as white crystalline solids while the diamines lb,c are viscous oils. All five compounds can be prepare in 50-80% yield on a scale of 5-10 g. -78"C/THF LiNHR ^ -2 LiBr (1) (a) R = 2,6-'Pr2C6H3 (b) R = 2,6-Et2C6H3 (c) R = 2,6-Me2C6H3 1a"e (d) R = 2,4,6-CI3C6H2 (e) R = 2,4,6-Br3C6H2 The diamines la-e react cleanly with Zr(NMe2)4l to give two equivalents of HNMe2 and the yellow crystalline mixed amide complexes 2a-e in greater than 90 % yield (eq. 2). (2) 1a-e 2a-e References on page 190 94 The room temperature 'H NMR spectra of complexes 2a-e display a sharp singlet for the ligand methylene protons (NC//2) consistent with a meridional coordination mode of the ligand. Moreover, the isopropyl methyl groups of complex 2a and the ethyl methylene protons of complex 2b are diastereotopic, which is interpreted as a consequence of restricted rotation about the N-C^,bond. There is no direct spectroscopic means to determine if the same restricted rotation exists for complexes 2b,d,e, however, modeling78 studies indicate that the barrier to rotation is high. Chloride derivatives were desired as precursors to alkyl derivatives. The addition of (Me2NH2)Cl, (PyH)Cl or (LutH)Cl to complex 2a results in protonolysis of the BDPP ligand to yield the diamine la. Similar reactivity has been observed for other chelating amide derivatives of zirconium79. The aryl substituents in the 2,6-position do not seem to kinetically protect the ligand from proton attack. In contrast, a highly selective reaction between compounds 2a-e and excess ClSiMe3 affords the white crystalline dichloride derivatives in nearly quantitative yield (eq. 3). 2a-e 3a-e The dichloride complexes 3a-e are very soluble in THF, CH2C12 and CHC13, soluble in aromatic solvents, and insoluble in aliphatic solvents. The !H NMR spectra of complexes 3a-e indicates that the meridional coordination of the pyridine-diamide ligand and restricted rotation about the N-Q bond are retained upon chlorination. In an attempt to generate the dichloride derivative 3a in a single step, compound la was reacted with ZrCl2[N(SiMe3)2]280 in toluene at room temperature (eq. 4). A yellow oily solid (4a) was isolated by evaporation of the solvent. The 'H NMR spectrum of complex 4a displays References on page 190 95 an AB quartet for the ligand methylene protons (NC/Y2) indicating asymmetry about the N3Zr plane. The two isopropyl methine and the four isopropyl methyl resonances are also consistent with meridional coordination of the ligand and restricted rotation about the N-Cipso bond. Moreover, the two SiMei singlets (8 0.27 and 0.16 ppm) indicate the presence of one equivalent of coordinated HN(SiMe3)2 and one equivalent of free NH(SiMe3)2. A cis arrangement of the HN(SiMe3)2 relative to the pyridine is proposed based on the observed asymmetry. It is noteworthy that there is no evidence of coordination of Me2N(SiMe3) in the products obtained in eq. 3. R R NH // x\ // vx \ sNH(SiMe3)2 (4) / ^ Toluene/RT / ^ » / 1 ' « N+ ZrCI2[N(SiMe3)2]2 N—Zr Cl HN(SiMe3)2 \ / J\ —\CI / •NH ^—N R R 1a 4a The reaction of the dichloride 3a-e with two equivalents of MeMgBr affords the white crystalline dimethyl derivatives 5a-e in 80-90 % yield (eq. 5). R j—N f \ \ >CI Et2o/RT r~K \ >Me (5) (' N— Zr' +2 MeMgBr— • (/ N—Zr^ \=/ y>Q,\ I^Me >—N R 3a-e The 'H and ''Cf1!!} NMR spectra for complexes 5a-e are very similar to those obtained for complexes 3a-e with additional resonances for the Zr-CH3 group (Zr-C//3, ca. 0.50 ppm; Zr-CH3, ca. 45 ppm). These data are comparable to literature values for other zirconium methyl derivatives23,80-83 References on page 190 96 The solid state structure of complex 5b was determined by X-ray crystallography. The molecular structure of complex 5b can be found in Figure 2- 10 and relevant bond distances and angles in Table 2- 1. The complete data set can be found in the Appendix. Table 2- 1. Selected Bond Distances (A) and Angles (deg) for 5b Bond Distances Zr(l) -C(l) 2.248(7) Zr(l)-C(2) 2.243(6) Zr(l) -N(l) 2.325(4) Zr(l)-N(2) 2.101(4) Zr(l) -N(3) 2.104(5) Bond Angles N(2)- Zr(l) -N(3) 139.6(2) C(l)-Zr(l) - C(2) 102.4(3) N(2)- Zr(l) -N(l) 70.0(2) N(3)-Zr(l) -N(l) 69.7(2) Zr(l) -N(3) -C(3) 126.4(3) Zr(l)-N(3) - C(20) 121.5(3) C(3)- N(3)- C(20) 112.0(4) Zr(l)-N(2) -C(9) 126.2(3) Zr(l) -N(2) -C(10) 122.7(4) C(9) - N(2) - C(10) 111.0(4) The structure can best be described as a distorted trigonal bipyramid with the amide nitrogens (N(2) and N(3)) occupying the axial positions. The zirconium atom lies 2.4° out of the plane of the three nitrogen atoms. The Zr-amide distances (2.105(5) and 2.101(4) A) are comparable to other zirconium-amido complexes8'84-88 Each amide is sp2-hybridized as evidenced by the sum of the angles about each nitrogen (N(2) = 359.9° and N(3) = 359.9°). The aryl rings lie perpendicular to the plane of the ligand with dihedral angles of 89.8° and 89.6°. The rigid coordination of the ligand and enforced location of the aryl ethyl groups necessarily protects the metal about the N3-plane. References on page 190 97 Figure 2-10. Molecular structure of complex 5b deduced from X-ray crystallography References on page 190 98 2.1.1 MO calculation The coordination sphere of compound 5b resembles that of Cp2ZrMe2^9 (Figure 2- 11). The amide-Zr-amide and Me-Zr-Me angles in 5b are about 7° larger than the Cent-Zr-Cent (Cent = Cp centroid) and Me-Zr-Me angles in Cp2ZrMe2, as expected for a distorted trigonal bipyramid versus a distorted tetrahedron. Moreover, the Zr-Me bond and the L-Zr (L = amide, Cent) of complex 5b and Cp2ZrMe2 are comparable and hence the frontier orbitals of each fragment (less the Zr-Me groups) should be similar. Extended Hiickel molecular orbital calculations7^ were performed on a model (5') derived from the molecular structure of complex 5b and compared to the frontier orbitals of Cp2 Zr90 (Figure 2- 12). The complete MO calculations data can be found in the Appendix. The b2 orbital of Cp2Zr and the 5b2 (dK) orbital of 5' have very similar energies as a consequence of limited n-donation from the pyridine-nitrogen to the zirconium (contribution: Zr = 90.6 %; N idjne =1.3 %). In contrast, the 13aL (dx2.y2) orbital of 5' is raised in energy relative to the 2a, orbital of Cp2Zr due to significant a-donation from the pyridine (contribution: Npyridine =11.1 %). This also raises the energy of the 12a, (dz2) orbital of 5', although to a much lesser extent (contribution: Zr Figure 2-11. Geometry of complex 5b versus that of Cp2ZrMe2 = 99.3 %; N, pyridine = 0.5 %). References on page 190 99 Figure 2- 12. Molecular orbital diagram, (PyN2)M Vs Cp2M It was noted that the reaction of the mixed amide complex 2a (BDPP)Zr(NMe2)2 with [Me2NH2]Cl resulted in the protonolysis of the more basic amides of the pyridine-diamide ligand. This is consistent with the observation of a ligand centered non-bonding pair of electrons on the amides (Figure 2- 13, 4b2, contribution: Zr = 4.2 %; = 75.8 %). The 2^ orbital of 5' represents the amide-zirconium 7t-bonding combination while the 4a2 orbital constitutes the n-anti-bonding combination. Consequently, the pyridine-diamide ligand is formally an 8-electron References on page 190 100 donor, four electrons less than the combination of two cyclopentadienyl ligands. As a result, the zirconium atom in complexes bearing the pyridine-diamide ligand .should be more electrophilic than a metallocene-based complex. 2a2, bonding filled \\ // 4b2, non-bonding filled 4a2, anti-bonding empty Figure 2- 13. Orbital interactions between the amide ligands and the metal 2.1.2 Reactivity of complex 5a Complex 5a reacts cleanly with one equivalent of T3uNH2 at room temperature in hexanes to give the mixed amide-alkyl complex 24a and one equivalent of methane (eq. 6). NR y—NR \ . MP hexanes/RT / \ \ N—Zr^^ + fBuNH2 j 'Me •NR 5a, R = 2.6-'Pr2C6H3 N—Zr. >NHfBu (6) 24a The AB quartet observed for the ligand methylene (NCH2) protons in the 'H NMR spectrum of complex 24a is consistent with asymmetry about the ZrN3 plane and a complex with Cs geometry. The amine proton (N/fBu) appears as a broad singlet at 5 3.98 ppm. Compound 24a appears to be ideally suited for an alkane elimination between the amide and methyl groups to give an imido complex. Moreover, the 13a,, 5b2 and 10b, orbitals of the metal are of appropriate symmetry for the formation of pseudo M=N triple bond^l (Figure 2- 14). References on page 190 101 NO 13a! 10b! 5bc Figure 2- 14. Metal-imido pseudo triple bond The thermolysis of compound 24a results in the activation of one of the ligand isopropyl methyl groups (eq. 7). One equivalent of methane is released during the reaction and was detected by 'H NMR spectroscopy. NR \ >xvNNHfBu CsDs/scrc NR \ ,**NHfBu -CH, 24a, R = 2,6-'Pr2C6H3 (7) ...w\l 25a The 'H NMR spectrum of complex 25a displays two AB quartets for the ligand methylene protons (NCH2), seven doublets for the isopropyl methyls, three septets for the isopropyl methines and one multiplet for the activated isopropyl group consistent with C;-symmtery. The amine proton (NT/JBu) appears as a broad singlet at 6 4.02 ppm. The solid state structure of complex 25a was determined by X-ray crystallography. The molecular structure of complex 25a is shown in Figure 2- 15 and selected bond distances and angles can be found in Table 2- 2. The complete crystallographic data can be found in the appendix. References on page 190 References on page 190 103 Table 2- 2. Selected Bond Distances (A) and Angles (') for Complex 25a' Bond Distances Zr(l)-N(l) 2.352 (8) {2.313 (9)} Zr(l)-N(4) 2.036(9) {1.893 (12)} Zr(l)-N(2) 2.106 (7) {2.061 (9)} Zr(l)-C(31) 2.268 (12) {2.65 (2)} Zr(l)-N(3) 2.093 (8) {2.090 (8)} N(4)-C(32) 1.401 (14) {1.44 (2)} Bond Angles N(2)-Zr(l)-N(3) 139.6 (3) {140.6 (4)} N(4)-Zr(l)-C(31) 103.1 (4) {97.3 (9)} N(l)-Zr(l)-N(4) 145.8 (4) {160.4 (7)} N(2)-Zr(l)-C(31) 109.1 (4) {108.3 (7)} Zr(l)-N(4)-C(32) 152.1 (9) {162 (2)} N(3)-Zr(l)-C(31) 88.7 (4) {81.8 (6)} N(l)-Zr(l)-C(31) 111.1 (4) {102.2 (6)} a: numbers in brackets for second asymmetric molecule Two asymmetric molecules were located in the unit cell. The four nitrogen atoms are located in the basal plane of a squared^ased pyramid and the activated isopropyl carbon occupies the apical position. The high Zr-N-C bond angle (152° and 161.5°) is too large for a simple amide ligand and suggests the presence of significant cc-hydrogen agostic interaction. The proposed agostic interaction is consistent with the abscence of an N-H stretch in the IR spectrum of complex 25a. The geometry about the nitrogen of the '""Bu-amide group suggests that the proton is located trans to the activated carbon. A similar agostic interaction is proposed for complex 24a. Although the necessary labelling studies have not bee performed, a possible mechanism for the formation of complex 25a may involve a highly reactive imido compound (Scheme 2- 1, I). The newly formed imido complex activates one of the ligand isopropyl methyl C-H bonds. References on page 190 104 R = 2,6-'Pr2C6H3 Scheme 2- 1. Proposed mechanism for ligand CH activation Other imidozirconium complexes bearing amide ancillary ligands undergo C-H activation of alkanes and arenes92"94. por example, the transient bis(amido)imido complex (Tju3SiNH)2Zr=NSiTBu3 has been shown to add the C-H bond of benzene and methane across the Zr=N linkage92. 2.1.3 Other alkyl complexes Complexes 3a-c can be alkylated using various alkylating reagents (Scheme 2- 2). The addition of 2.2 equivalents of PhCH2MgBr to ether suspensions of 3a-c at -78 °C affords the bright yellow dibenzyl derivatives 6a-c in good yield. Alternatively, complexes 6a-c can be synthesized from Zr(CH2Ph)495 and the diamines la-c in toluene at room temperature. References on page 190 105 Scheme 2- 2. Alkylation of complexes 3a-b* ¥ Reagents and conditions, (i) 2 equivalents PhCH2MgBr, Et,0, 23 °C; (ii) 2.2 equivalents LiCH2SiMe3, Et.0, -20 °C; (iii) 1.3 equivalents (C4H6)Mg*2THF, Elfi, -20 °C; (iv) 2.2 equivalents PhMgCl, Et,0, -30 °C; (v) 1.2 equivalents PhMe2CCH2MgCl, Et^O, -20 °C; (vi) 1.2 equivalents NaCp#DME, EtjO, -20 °C1 (vii) 2.5 equivalents PrMgCl, hexanes, -30 °C; (viii) 2.5 equivalents BuMgCl, hexanes, -30 °C. References on page 190 106 The room temperature 'H NMR spectrum of complex 6a displays broad resonances for all the signals but those corresponding to the meta and para protons of the pyridine ring. This suggests facile exchange of differing groups on either face of the plane defined by the pyridine ring. The 'H NMR spectrum of this complex is well resolved at -40°C as shown in Figure 2-17. At this temperature, two septets (©) and an AB quartet ((D) are observed for the C//(CH3)2 and the NC//2 protons, respectively. These observations combined with the two distinct C//2Ph signals (2.10 and 1.64 ppm, not shown) and the high-field ortho-H resonance (5.90 ppm, G>) of one ot the CH2Ph groups suggest two different benzyl environments. Although NMR spectroscopy is insufficient to unequivocally establish the coordination mode, these resonances are characteristic of a r|2-PhCH2 group (Figure 2- 16)96-98 Figure 2- 16. rf-CH2Ph group The high temperature limiting spectrum displays a singlet for the ligand methylene protons (NC/i/2) and a single sharp resonance attributable to the C//2Ph protons. These resonances are characteristic for a complex with C2v symmetry. The resonances coalesce at 10 °C yielding a barrier to 'benzyl flipping' (eq. 8) of AG* = 13.5 (5) kcal mol"1. In contrast to complex 6a, the room temperature 'H NMR spectra of compounds 6b and 6c display sharp resonances for species with C2v symmetry. However, upon cooling both compounds show resonances consistent with both T)1- and Tp-benzyl ligands (Table 2- 3). Table 2- 3. Fluxional rj'-T]2-CH2Ph Complex Coalescence temperature (°C) AG* (kcal/mol) 6a 10 13.5 (5) 6b -20 11.5(5) 6c -30 11.2 (5) References on page 190 107 References on page 190 108 0 Interestingly, the low temperature (-80 °C) limiting spectrum of compound 6c displays two distinct resonances for the inequivalent aryl methyl groups consistent with restricted rotation about the N-C; bond at this temperature. The room temperature !H NMR spectrum" of the metallocene bis(benzyl) derivative Cp2Zr(CH2Ph)2 shows no evidence of r|2-benzyl ligands. This is likely a result of the reduced electrophilicity of the metal in a metallocene fragment compared to a bis(amide) complex. As further evidence, the structurally characterized cationic benzyl derivative [Cp2Zr(r(2-CH2Ph)(NsCMe)]+(BPh4)" and the spectroscopically identified base-free complex [(ri5-C5H4Me)2Zr(ri2-CH2Ph)]+(BPh4)"965 clearly show the presence of an rj2-benzyl moiety. Yellow single crystals of (BDPP)Zr(rf-CH2Ph)(CH2Ph) (6a) suitable for an X-ray analysis were grown by diffusion of cyclohexane into a saturated CH2C12 solution of complex 6a. The poor quality of the crystallographic data limited the refinement of the final structure and only connectivity could be established. Attempts to grow better quality crystals from different solvent mixtures were unsuccessful. The molecular structure of complex 6a (Figure 2- 18) clearly shows that one of the two benzyl groups is coordinated as an r]1 ligand with no significant Zr-Cipso interaction (Zr-C(4): ca. 3.2 A; Zr-C(l)-C(4): ca. 110"). The second benzyl group is bound in an T|2 fashion. The acute Zr-C(2)-C(3) angle (ca. 80°) results in the close proximity of the phenyl ring. The Cipso is particularly close to the metal with a Zr-C(3) bond distance of approximately 2.6 A (typical Zr-Cipso bond distances for similar complexes range from 2.59 A to 2.64 A)96-98 References on page 190 109 Figure 2- 18. Molecular structure of complex 6a References on page 190 110 The geometry about the zirconium is best described as a square-based pyramid with the benzylic carbon of the r|'-CH2Ph in the apical position. The three nitrogen atoms and the benzylic carbon of the r|2-CH2Ph are located in the remaining four sites. Complex 6a was reacted with one equivalent of B(C6F5)3100 in C6D6 and the solution behavior of the product was studied by 'H NMR spectroscopy (eq. 9). (C6F5)3Be NAr . \ / 'r' r=J (9) \ ^CH2Ph B(C6F5)3 f=\ © \ ) " j ^CH2Ph NAr Ar = 2,6-'Pr2C6H3 6a 23a The 'H NMR spectrum of complex 23a shows two sets of benzyl resonances. One set of resonances appear at 6.75 (t), 6.58 (t), 6.38 (d) and 2.40 (s) ppm which is typical for ri'-benzyl group bound to zirconium96,98,l()l,102 A doublet at 6.25 ppm, triplet at 6.27 and triplet at 6.04 ppm are observed for the benzyl group bound to the boron. Although it is not possible to establish with certainty the cation-anion interaction, these resonances combined with the broad signal at 3.57 ppm (PhC//2B) are indicative of a r)6-PhCH2 group of a {(T)6-PhCH2)B(C6F5)3} moiety103'105. No "free" {(PhCH2)B(C6F5)3) anion was observed by 'H NMR spectroscopy104. The implications of this reaction on the catalytic activity of complex 6a in the polymerization of ethylene are discussed in the following sections. Compounds 3a-c react cleanly with NaCp»DME in EtjO at -20 °C to give the mono(cyclopentadienyl) derivatives 12a-cin good yield (Scheme 2- 2). The 'H NMR spectra of complexes 12a-c are consistent with rf-coordination of the cyclopentadienyl ligand. It is noteworthy that the geometry about the zirconium in the T|5-Cp complexes (12a-c) is closely related to that of the proposed T|6-PhCH2 complex 23a (Figure 2- 19). It has been proposed106 that the tris(methylcyclopentadienyl) derivative (C5H4Me)3ZrCl contains two Tf-coordinated References on page 190 Ill MeCp rings and one if-coordinated ring. There is no evidence of an V-Cp ligand in the low temperature 'H NMR spectrum of complex 12a. 23a 12a-c Figure 2- 19. rf-Cp vs rf-PhCH2 structures The addition of 2.2 equivalents of LiCH2SiMe3 to a diethyl ether solution of complexes 3a-c yields the bis(trimethylsilylmethyl) derivatives 7a-c (Scheme 2- 2) in high yield. The room temperature JH NMR spectra of compounds 7b and 7c are consistent with complexes with C2v symmetry. For example, the 'H NMR spectrum of complex 7c displays a singlet for the ligand methylene protons and resonances attributable to two equivalent CH2SiMe3 ligands. In both cases, the spectrum remains unchanged from -80 °C to +80 °C. In contrast, the room temperature 'H NMR spectrum of complex 7a, which bears the bulky 2,6-diisopropylphenyl substituents, is broad and featureless. The high temperature (+70 °C) limiting spectrum shows resonances for the expected C2v-symmetric product. The low temperature limiting spectrum displays sharp resonances consistent with asymmetry about the N3M plane and a complex with Cs-symmetry. For example, an AB quartet is observed for the ligand methylene protons (C//2N). The absence of fluxionality in complex 7b and 7c suggests that the origin of this behavior in compound 7a is steric and not electronic. Steric interactions between the isopropyl substituents and the trimethylsilyl groups in compound 7a may prevent the two alkyl groups from being simultaneously directed outward (Figure 2- 20,1). References on page 190 112 (I) (II) Figure 2- 20. Fluxional behavior of complex 7a The resonances coalesce at 20 °C yielding a barrier to 'trimethylsilylmethyl flipping' of AG* = 13.4 (5) kcal mol"1. Interestingly, both trimethylsilyl groups are arranged in the least sterically hindered position (both directed outward) in the molecular structure of Cp2Zr(CH2SiMe3)2107. Complex 3a reacts with PhMgCl in EtjO at -30 °C to give the diphenyl complex 8a (Scheme 2- 2). The 'H NMR spectrum for complex 8a displays a single sharp resonance for the ligand methylene protons (C//2N) and two doublets for the ligand isopropyl methyl groups as expected for a complex with C2v-symmetry. The 13C{'H} NMR spectrum displays a low-field resonance (5 190.41 ppm) for the phenyl ipso-carbon similar to other reported values^8. The thermolysis of Cp2ZrPh2109,l 10 m toluene or benzene at 70 °C affords a complicated mixture including benzene. It is believed that the decomposition involves a benzyne-zirconium intermediate (Figure 2- 21) which then reacts with the aromatic solvent to give Cp2Zr ArPh 111. Complex 3a does not react when heated to 110 °C for 7 days in toluene. Figure 2- 21. Cp2Zr(benzyne) References on page 190 113 The addition of excess PhMe2CCH2MgCl to complex 3a in Et^O at -20 °C affords the mono(neophyl) derivative 10a (Scheme 2- 2). The 'H NMR spectrum of complex 10a displays an AB quartet for the ligand methylene protons (C//2N) as well as two isopropyl methines and four isopropyl methyl resonances as expected for a complex with asymmetry about the N3M plane and restricted rotation about the N-C/pjo bond. A similar reaction using complex 3b affords what appears (by 'H NMR spectroscopy) to be the bis(neophyl) derivative (BDEP)Zr(CH2CMe2Ph)2. The complex is, however, unstable and decomposes within days at room temperature. The dichloride complexes 3a-c react with Mg(C4H6)»2THF in ether at -20 °C to give the zirconium diene derivatives 13a-c (Scheme 2- 2). The proton NMR spectrum of complex 13a (Figure 2- 22) displays two ligand methylene (C//2N) singlets. This is characteristic of a complex with Cs-symmetry where the mirror symmetry is perpendicular to the plane of the meridionally coordinated pyridine diamide ligand. Similar resonances for the ligand methylene protons (C//2N) are observed in the proton NMR spectra of complexes 13b,c. The presence of two isopropyl methine and four isopropyl methyl resonances in the 'H NMR spectrum of complex 13a is also consistent with this symmetry and indicates restricted rotation about the N-Cipso bond. The diene fragment resonances observed in the *H NMR spectra of complexes 13a-c (Table 2- 4) suggest an s-cis bent metallacyclo-3-pentene structure 112,113 wuh significant n-donation from the metallacyclopentene double bond (Figure 2- 23). Table 2- 4. Butadiene 'H NMR resonances of complex 13a-c Complex Hm 8, ppm Hs Ha 13a 4.72 3.56 0.28 13b 4.92 3.41 0.16 13c 4.98 3.42 0.17 References on page 190 114 References on page 190 115 m -diene s-frans-r|-diene Figure 2- 23. Coordination modes of butadiene The metallocene-based diene complexes Cp2Zr(diene) and Cp2Hf(diene) often show fluxional behavior where (he topomerization occurs through a planar 16-electron metallacyclopentene transition state (Scheme 2- 3, 1)114-117 JYIC activation barriers vary between 6.5 and 12.4 kcal mol"1, H5,l 16,118 depending upon the steric bulk of the diene ligands. Moreover, the zirconocene derivative Cp2Zr(r|4-C4H6) exists in two isomeric forms having the butadiene coordinated in either the s-cis or s-trans configuration112. The mode of coordination of the conjugated diene is controlled not only kinetically but also thermodynamically. In general, dienes bearing alkyl or aryl substitution at the C, and/or C4 atoms kinetically favor the coordination in the s-trans form. On the other hand substitution at the C2 and/or C3 carbons always brings about the predominance of s-cis coordination (Table 2- 5)114,117,119,120 However, the s-trans isomer in some cases isomerizes to the more thermodynamically stable s-cis isomer upon heating. The activation barrier (AG*) for the interconversion of Cp2Zr(butadiene) is M Scheme 2- 3. Topomerization of s-cis-metallacyclopentene References on page 190 116 calculated to be 23 kcal mol"1 and that for Cp2*Zr(butadiene) is estimated to be >30 kcal mol" 1119,120. Table 2- 5. s-Cis /s-Trans ratio (%)for Cp2(R'CH=CR2CR3=CHR4) in C6D6 R1 R2 R3 R4 S'ds/s-trans Ph H H H 2/98 H H H H 10/90 -60/40" H CH, H H 100/0 a Varied depending on the temperature In contrast, no evidence of r)4-diene coordination is observed for complexes 13a-c. Furthermore, the C5-symmetry of compound 13a is retained to +80 °C and no evidence of syn/anti proton exchange is observed; consistent with rigid coordination of the diene fragment to the highly electrophilic zirconium center and a significandy stronger ^-interaction with zirconium. The solid state structure of complex 13a was determined by X-ray crystallography. The complete data set can be found in the Appendix. The molecular structure of complex 13a can be found in Figure 2- 24 and relevant bond distances and angles in Table 2- 6. The molecular structure of complex 13a is best described as a distorted trigonal bipyramid with the two amides located in the axial positions and the pyridine-nitrogen and the a-carbon of the diene fragment occupy the equatorial positions. The amide- and pyridine-zirconium bond distances are statistically the same as those found in complex 5b (Table 2- 1 and Figure 2- 10). The long-short-long bond alternation in the diene fragment coupled with the short Zr-C(17) and long Zr-C(18) bonds, confirm the s-cis bent metallacyclo-3-pentene formulation. References on page 190 117 Figure 2- 24. Molecular structure of complex 13a from X-ray crystallography References on page 190 118 Table 2- 6. Selected Bond Distances (A) and Angles (°) for complex 13a Bond Distances Zr-N(l) 2.307 (13) Zr-C(18) 2.47 (2) Zr-N(2) 2.111 (8) Zr-C(19) 2.47 (2) Zr-N(2A) 2.111 (8) C(17)-C(18) 1.56 (3) Zr-C(17) 2.36 (2) C(18)-C(19) 1.36 (3) Zr-C(20) 2.33 (2) C(19)-C(20) 1.55 (3) Bond Angles N(2)-Zr-N(2A) 140.0 (4) Zr-C(20)-C(19) 37.5 (7) N(l)-Zr-C(17) 133.3 (6) C(17)-C(18)-C(19) 126 (2) N(l)-Zr-C(20) 141.4 (7) C(20)-C(19)-C(18) 121 (2) Zr-C(17)-C(18) 37.7 (7) The qualitative molecular orbital diagram describing the bonding of a diene ligand with the pyridine-diamide-zirconium fragment is shown in Figure 2- 25. Overlap of the 5b2 and 13a, frontier orbitals of the (PyN2)Zr fragment with the filled a, and a2 orbitals of the diene {carbons C(17) and C(20)} account for the o-bonds between Zr and these carbons. Mixing between the 7t, {C(18) and C(19)} and the 10b, orbital of the metal fragment results in the formation a filled K-type molecular orbital. a-, cr2 Hi Figure 2- 25. Bonding interactions for complexes 13a-c. References on page 190 119 This is consistent with a 2a-1 TT bonding mode of the diene and the s-c/.y-bent metallacyclo-3-pentene molecular structure. The diene complex 13a does not react with unsaturated substrates over several days at 23 °C. However, products derived from insertion into the Zr-C a-bond are observed upon heating to 90 °C in benzene (Scheme 2- 4). (a) R = 2,6-'Pr2C6H3 16a Scheme 2- 4. Reaction of complex 13a with unsaturated substrates The 'H and 13C{1H} NMR spectra of complexes 14a, 15a and 16a show resonances characteristic for the Zr-allyl functional group and one a-vinyl group 121-125 jhe 'H NMR spectrum of complex 14a displays two AB quartets for the ligand methylene (NC//2) protons indicative of a complex with C; symmetry. There is no evidence for syn/anti proton exchange in the allyl group to 80 °C, suggesting that this moiety is firmly coordinated to the electrophilic zirconium center. The metallocene-based complex Cp2Zr(r|4-isoprene) reacts with 2-butyne to give a similar a,rc-allyl derivative which has been structurally characterizedl2^. References on page 190 120 The reaction of compound 13a with excess HC=CSiMe3 affords a single isomer derived from 2,1-insertion of the acetylenic unit into the zirconium-carbon bond. The substitution pattern of the complex is established on the basis of 'H NMR spectroscopy, 'H COSY and NOE experiments. For example, irradiation of the low-field signal (8 8.02 ppm) results in an enhancement of the metallacycle C=C-CH2 protons (Figure 2- 26). The irradiation of other groups is also consistent with 2,1-insertion. The reaction of complex 13a with excess 1-hexene affords a single isomer derived from 2,1-insertion of the a-olefin into the Zr-C bond. The presence of two AB quartets for the ligand methylene protons (NCH2) is consistent with a complex with C, symmetry. The 2,1-insertion of the olefin was confirmed by 13C-APT spectroscopy. An inverted peak is observed for the carbon attached to the zirconium characteristic of a tertiary carbon. In a similar way, most 1-alkenes (1-butene, 1-octene, etc.) react with Cp2Zr(diene) in a 1,2 fashion to give complexes with one G- and r)3-allyl M-C bonds^21-123 The reaction is believed to result from a [2+2]-type oxidative coupling of the alkene and the diene (Scheme 2- 5)113 Scheme 2- 5. Reaction of Cp2Zr(diene) with a-olefins The reaction of complex 3a with 2.2 equivalents of PrMgCl or BuMgBr affords the di(alkyl) derivatives 17a and 18a, respectively (Scheme 2- 2). The 'H NMR spectra of complexes 17a and 18a display the resonances expected for complexes with C2v symmetry. The reaction of complex 3a and 2.2 equivalents of EtMgCl does not afford the expected diethyl derivative (BDPP)ZrEt,. The 'H NMR spectrum of the crude reaction mixture is References on page 190 121 consistent with activation of one of the isopropylmethyls of the ligand. Attempts to isolate the ligand activated complex were unsuccessful as a result of the high solubility of the compound. Related complexes (21a and 22a) were obtained by the thermolysis of complexes 17a and 18a (80°C, C6D6, 12 hours), respectively (eq. 10). The 'H NMR spectrum of complex 21a (Figure 2- 27) displays two AB patterns (G)/©) for the ligand methylene (NC7/2) protons and three isopropyl methine resonances (©). These resonances are consistent with Cj-symmetry and activation of one of the ligand isopropylmethyl groups. Ar Ar (10) 17a, R = Pr 21a, R = Pr 18a, R = Bu 22a, R = Bu Charaterization of the gas formed by the reaction of complex 3a and two equivalents of D5-EtMgCl showed that CD3CD3 is formed. Moreover, no butene was detected from the thermolysis of complex 18a (within the detection limits of 'H NMR spectroccopy). Based on these observations, two mechanisms can be proposed for these reactions. The first pathway (Scheme 2- 6,1) involves P-hydride elimination, followed by alkane reductive elimination to give a Zi^-olefin complex. A similar reaction has been observed with dialkylzirconocene complexesl26. The activation of the isopropyl methyl C-H bond results in the formation of a mono(hydride) alkene complex. Insertion of the olefin into the M-H bond affords the final product. A similar pathway, which involves a metal centre with a d2-electronic configuration, has been proposed for ligand activation of titanium pyridine diamide complexes (chapter one). This References on page 190 122 route is not likely given that no olefins was oberved in a sealed tube experiment which requires quantitative reinsertion of the olefin in the metal-hydride bond. The second route (Scheme 2- 6, II) involves the formation of an alkylidene intermediate via oc-elimination of alkane. The proposed alkylidene intermediate is very similar to the imido species proposed earlier for ligand activation of an alkyl-amido complex (Scheme 2- 1). Moreover, a-elimination in the presence of (3-hydrogens has been reported for tungsten amide complexes 127 and alkylidene complexes of zirconium are known 128-130 =( \ NAr. R -J N-Zr — H RH2CH^C_ NAr A - RH v\ N-Zr^ 2 2 / ^CH2CH2R NAr RH /— NAr ( N-Zr = CHCH2R M / ^NAr ^-NAr ^-NAr R R = H, Me, Et r-NAr A N-Zr = CHCH2R_ — N NAr x ^NAr /==( \ vX\CH2CH2R Scheme 2- 6. Mechanism of ligand C-H activation References on page 190 123 References on page 190 124 References on page 190 125 2.2 Ortho-substituted aryl diamido complexes As previously noted, bis(2-phenyl-indenyl)zirconiumdichloride acts as a catalyst precursor for the polymerization of propylene in a stereoblock fasion. The indenyl ligands rotate about the metal-ligand bond and cause the catalyst to isomerize between chiral-like and achiral-like structures. The chiral-like C2-geometry leads to isotactic polypropylene while the achiral-like Cs-geometry generates atactic polypropylene, resulting in a stereo block copolymer (Figure 2- 6). With this oscillating catalyst system in mind, several ortho-substituted aryl diamido complexes of zirconium were prepared. Restricted rotation about the N-Cj/wo bond has been observed for pyridine diamide complexes bearing 2,6-disubstituted phenyl groups. A small enough ortho-substituent might allow some rotation about the N-C, bond. The resulting complex would alternate between chiral-like and achiral-like geometries in a way similar to the bis(2-phenyl-indenyl)zirconiumdichloride complex (Figure 2- 28). rac, C2 meso, Cs Figure 2- 28. Asymmetric ligand The reaction of two equivalents of LiNHR (R = 2-phenylphenyl, 2-isopropylphenyl, 2-'butylphenyl, 2-isopropyl-6-methylphenyl) with 2,6-bis(bromomethyl)pyridine77 yields the diamine (BPhP)H2 (If), (BMPP)H2 (lg), (BMBP)H2 (lh) and (MPPP)H2 (li) (eq. 11). Compounds lg,h,i can be isolated as white crystalline solids while the diamine If is a viscous References on page 190 126 oil. All four compounds can be prepared in nearly quantitative yield (by 'H NMR spectroscopy) on a scale of 5-10 g. f N + -78'C/THF LiNHR ^ (11) \ / -2LiBr^ \ Br (f) R = 2-PhC6H4 (g) R = 2-'PrC6H4 (h) R = 2-'BuC6H4 (i) R = 2-'Pr-6-MeC6H3 The diamines lf-i react cleanly with Zr(NMe2)41 at 23 °C to give two equivalents of HNMe2 and the yellow crystalline mixed amide complexes 2f-i (eq. 12). The amide complexes 2f-h are isolated from hexanes in >90 % yield, however, the high solubility of compound 2i in hexanes limits its isolation. These aminolysis reactions are unaffected by the presence of excess dimethylamine5^ hence only the kinetic products are observed. R NH 23'C/Toluene ^ \ vN\NMe2 (12) + Zr(NMe2)4 • - 2 HNMe2 f, R = 2-PhC6H4 g, R = 2-'PrC6H4 h, R = 2-'BuC6H4 i, R = 2-'Pr,6-MeC6H3 The room temperature 'H NMR spectrum for complex 2f exhibits a single sharp resonance for the methylene protons of the ligand (NC//2) and a singlet for the dimethylamido groups. These observations are consistent with C2v-symmetry resulting from free rotation about the N-C; bond. The spectrum remains unchanged to -80 °C. Modeling studies^ on compound 2f, using the X-ray coordinates of complex 5b as a starting point, predict a large References on page 190 127 barrier to rotation about the N-Ci/W0 bond when the o-phenyl groups pass by the dimethylamido groups (Figure 2- 29). Rotation about the Ph-Ar a-bond allows the o-phenyl groups to pass by the methylene protons of the ligand backbone without significant steric interactions. Furthermore, these calculations suggest that the ease of rotation decreases in the following way: o-Ph > o-'Pr > o-T3u {vide infra). The room temperature 'H NMR spectrum of complex 2g also exhibits a single sharp resonance (Figure 2- 30, ©) for the ligand methylene protons (NC//2), one septet (®) for the isopropyl methines and one doublet (Q)) for the isopropyl methyl groups. Again, this is consistent with free rotation about the N-C;/,,0 bond resulting in the spectroscopically observed C2v-symmetry. Unlike complex 2f, resonances attributable to two isomeric compounds are observed upon cooling complex 2g (Figure 2- 30). The low temperature (-80 °C) limiting 'H NMR spectrum of compound 2g in d8-toluene shows three dimethylamido (NA/e2) resonances (©) in a rado of 1:1:1.2. Moreover, overlapping ligand resonances are observed for the two complexes. For example, two AB quartets are observed for the ligand methylene protons (©). a-bond Figure 2- 29. Steric interactions in complex 2f References on page 190 128 References on page 190 129 These resonances are in agreement with an approximately 1.67:1 mixture of the Cs-symmetric meso and C2-symmetric rac rotameric isomers in solution at -80 °C (Figure 2- 31). The Q-symmetric meso rotamer has a mirror of symmetry that runs perpendicular to the ZrN3 plane. Therefore, the two isopropylphenyl methine groups are chemically and magnetically equivalent. Moreover, the isopropyl methyl groups appear as two doublets as a result of the rigid aryl orientation. The two dimethylamido ligands are not related by this mirror plane and appear as two singlets of equal intensity. On the other hand, the C2-symmetric rac rotamer has a C2 access of rotation coincidental with the pyridine-zirconium bond. Consequently, the two dimethylamido groups are related by symmetry and are equivalent. Similarly, the two isopropylphenyl substituents are also equivalent resulting in one isopropyl methine and two isopropyl methyl resonances. In both rotamers, the ligand methylene protons are inequivalent giving rise to two AB quartets (NC#A/YB). Figure 2- 31. Meso and rac rotameric isomers of complex 2g The resonances coalesce at -40 "C yielding a barrier to rotation of the aryl groups of AG* = 11.2 (5) kcal mol"1 131. References on page 190 130 References on page 190 131 In contrast to compounds 2f and 2g, the room temperature !H NMR spectrum for complex 2h displays resonances for two distinct species (Figure 2- 32). The 'H NMR spectrum of complex 2h displays three dimethylamido resonances consistent with the presence of both meso (CD and ©) and rac (©) rotameric isomers in a 2.6:1 ratio. Moreover, an AB quartet (©) for the ligand methylene protons (NCHAHB) and a singlet (O) for the equivalent 'Bu groups are observed for the rac isomer. In addition to these resonances, the meso isomer displays a singlet (Q)) for the rm-butyl substituents and an apparent singlet (©) is observed for the ligand methylene protons instead of the expected AB pattern. This is characteristic for a system where the chemical shift difference between HA and HBis small (A\) < 0.4 Hz)!32. The 13C{ 'H} NMR spectrum of complex 2h is also consistent with the presence of both rotamers. As noted above, the raclmeso ratio is unaffected by added dimethylamine. Thus, only the kinetic products are obtained. In contrast, the reaction of (EBI)H2 (EBI = l,2-bis(l-indenyl)ethane) with Zr(NMe2)4 initially yields (EBI)Zr(NMe2)2 in a raclmeso ratio of 2:1 but the ratio increases to 13:1 with time (100 °C, 17h)53 . This suggests that the amine elimination is reversible and that the meso and rac-complexes are formed at comparable rates but the rac isomer is the thermodynamically preferred product. Moreover, it was demonstrated that the epimerization of meso to rac is catalyzed by Me2NH and is inhibited when the amine is removed from the reaction mixture. Interestingly, the reaction of Me2Si(C5H4-3-'Bu)2 and Zr(NMe2)4 yields [Me2Si(C5H3-3-"Bu)2]Zr(NMe2)2 in a raclmeso ration of 1:2133. In this case, the higher meso preference is interpreted as a result of a lateral deformation of the ansa ligand system to reduce steric interactions. A similar 'deformation' whereby the metal adopts a square-based pyramidal (sbp) geometry instead of a trigonal bipyramidal (tbp) conformation is proposed to account for the preferred meso rotamer of compound 2h(Figure 2- 33). As a result of this deformation, some of the steric strain associated with the meso isomer is relieved relative to the rac isomer. It is not References on page 190 132 possible to distinguish spectroscopically between the proposed sbp and tbp complexes since both compounds possess C^-symmtery. Figure 2- 33. Structural deformation The energy difference between sbp and tbp geometries is expected to be quite small given the d° electronic configuration of zirconium. A similar change in hybridization has been observed in other d° group 4 complexes bearing the pyridine diamide ligand. The mono(neophyl) derivative [2,6-(RNCH2)2NC5H3]TiBr(CH2CMe2Ph) ( R = 2,6-Me2C6H3) (see chapter one) displays a sbp geometry in the solid state with the largest group occupying the apical position. This geometry minimizes the interaction between the orthomethyl groups of the aryl and the bulky neophyl ligand. In a similar way, the di(benzyl) complex (6a), exhibits a sbp geometry in the solid state. The room temperature ]H NMR spectrum for complex 2j displays resonances for two rotameric isomers. These species do not interconvert bwtween -80 °C and +80 °C. Restricted rotation about the N-Cf bond is expected for complexes bearing 2,6-disubstitued aryl groups. The raclmeso ratio of 1.3:1 (from 'H NMR spectroscopy) suggests that during the aminolysis References on page 190 133 reaction the aryl groups have minimal influence on one another; in other words, a near statistical distribution of isomers is produced. The mixed amide complexes 2f-i react with excess ClSiMe3 to afford the dichloride derivatives 3f-i in 80-90% isolated yield (eq. 13). Upon addition of ClSiMe3 the solutions turn black which is attributed to minor impurities given the high isolated yields. R R (13) R f, R = 2-PhC6H4 R 2f-i g, R = 2-'PrC6H4 3f_j h, R = 2-fBuC6H4 i, R = 2-'Pr,6-MeC6H3 Similarly to the mixed amide derivative 2f, the 'H NMR spectrum of complex 3f displays a sharp singlet for the ligand methylene protons (NCH2), consistent with rapid rotation about the N-Ci/wo bond. The room temperature 'H NMR spectrum of complex 3g displays broad featureless resonances for the methylene (NC//2), the isopropyl methine, and the isopropyl methyl protons of the ligand. The high temperature 'H NMR limiting spectrum (+60 °C) is consistent with rapid rotation about the N-CiA,so bond. The low temperature limiting spectrum (-60 °C) displays resonances for the two rotamers in a ratio of about 2:3. It is not possible to distinguish between Cs- and C2-symmetric compounds in the absence of NMR active groups in the equatorial plane of an idealized tbp geometry. As a result, it is not possible to discern which isomer predominates in solution. The resonances coalesce at +10 "C and the barrier to rotation is AG* = 13.8 (5) kcal mol -1. The raclmeso ratio in the mixed amide complex 2h is 1:2.6. Interestingly, a single isomer of the dichloride complex 3h is formed upon reaction with excess ClSiMe3. Again, it is not References on page 190 134 possible to distinguish between the rac and meso isomer in the absence of NMR active group in the equatorial plane of the tbp. However, the following results suggest that the meso rotamer is formed preferentially. The reaction of 3h with two equivalents of PhCH2MgCl or PhCMe2CH2MgCl yields the meso dibenzyl (6h) and dineophyl (9h) derivatives, respectively (eq. 14). Alternatively, the dibenzyl complex 6h can be prepared from Zr(CH2Ph)4^5 and the diamine lh. (14) meso-6h, R = fert-Bu; R' = CH2Ph meso-9h, R = tert-Bu; R' = CH2CMe2Ph The 'H NMR spectra of complexes 6h and 9h display a single AB quartet for the ligand methylene protons (NCHAHB) and one tert-butyl resonance in accordance with the presence of a single isomer. Moreover, two distinct benzyl resonances (ZrCH2Ph) are observed for compound 6h consistent with a C,-symmetric meso rotamer. Similarly, the 'H NMR of complex 9h displays two singlets for the neophyl methylene (C//2CMe2Ph) resonances and two singlets for the neophyl methyl (CH2CMe2Ph) groups. The mono(alkyl) derivatives [2,6-(RNCH2)2NC5H3]ZrClR' lOh (R' = CH2CMe2Ph) and llh {R' = Si(SiMe3)2} can be prepared from compound 3h and the corresponding alkylating reagent (eq. 15). References on page 190 135 (15) meso-Wh, R = tert-Bu; R' = ChfeCMe2Ph meso-11h, R = tert-Bu; R' = Si(SiMe3)3 Reaction conditions: lOh, PhCMe2CH2MgCl, CH2C12, -78 °C; llh, (Me3Si)3SiLi«3thf134, hexanes, -78 "C. The 'H NMR spectrum of complex lOh displays one AB quartet for the ligand methylene protons (NCHAHB), a singlet for the ligand tert-butyl groups, and two singlets (C//2CMe2Ph and CH2CMe2Ph) for the neophyl fragment. These resonances are consistent with the C^-symmetric meso isomer being the only species present in solution. The rac isomer can be ruled out since asymmetry about the ZrN3 plane removes the C2 rotational axis (Figure 2- 31). Thus, a complex with C; symmetry would be obtained. Similarly, the 'H NMR spectrum of complex llh displays resonances characteristic for the meso isomer. As expected, the 'H NMR spectrum of compound 3i displays resonances for two rotamers in a ratio of about 1.15:1. It would appear that no change in the isomeric ratio, within limits of detection, takes place during the metathesis reaction with ClSiMe3. The 'H NMR spectrum remains unchanged at 80 °C. The dichloride complexes 3f-i react with 2 equivalents of MeMgX (X = Cl, Br) to afford the dimethyl derivatives (5f-i) in 67-85 % yield as white crystalline solids (eq. 16). The 'H and References on page 190 136 ^Cj'H} NMR spectra of complexes 5f-i displays Zr-Me resonances similar to what has been obtained for complexes 5a-e and other related compounds23,80-83 (16) R f, R = 2-PhC6H4 R 3f.j g, R = 2-/PrC6H4 5M h, R = 2-fBuC6H4 i, R = 2-/Pr,6-MeC6H3 The 'H NMR spectrum of the 2-phenylaryl substituted complex 5f displays a single resonance for the Zr-Me groups down to -80 °C, consistent with free rotation about the N-Cipso bond and a C2v-symmetric complex The room temperature 'H NMR spectrum of complex 5g (Figure 2- 34) displays a singlet for the ligand methylene protons (NC//2), a septet for the isopropyl methine, a doublet for the chemically equivalent methyl groups, and a singlet for the Zr-Me2 groups. These resonances are consistent with free rotation about the N-C, bond and a C2v-symmetric complex. The low temperature (-60 °C) limiting spectrum shows overlapping resonances for the ligand methylene protons (NC//2), the isopropyl methines and the isopropyl methyl groups. Furthermore, three broad zirconium methyl resonances in a ratio of 1:1.3:1 are observed. These resonances are attributable to a raclmeso ratio of 1:1.5. The above resonances coalesce at -20 °C yielding a barrier to rotation of the aryl groups of AG! = 12.0 (5) kcal mol"1. References on page 190 137 138 As mentioned above, the reaction of the dichloride derivative 3h with bulky alkylating reagents affords exclusively C-symmetric complexes. Interestingly, the reaction of complex 3h with two equivalents of MeMgBr yields a mixture of rotameric isomers of the dimethyl complex (5h) in a ratio of about 1:3 (rac/meso). The 'H NMR spectrum of complex 5h remains unchanged from -80 °C to +80 °C as observed with other derivatives bearing a terf-butyl group in the 2-position of the aryl ring (3h and 4h). The isomerization to yield a mixture of rotamers can be rationalized in the following way. The metathesis reaction involves an octahedral four-centred transition state as shown in Figure 2-35, (II). The two Tiu groups in complex 3h direct the alkylating agent trans to the pyridine. Modeling studies^ on this transition state show that the barrier to rotation of the aryl group in the octahedral transition state is much less (ca. 19 kcal mol"1) than for the five coordinate complex (Figure 2- 35, I). When the incoming alkylating reagent is small (i.e., CH3MgBr), free rotation about the N-C, bond result in the isomerization of the complex and a mixture of rotamers is obtained (meso/rac, 3:1). Further isomerization is necessary to obtain a complex with the alkyl group located in the apical position. The non-statistical distribution of the two rotamers is interpreted as a result of some kinetic control inferred by the two rm-butyl groups on one another. Figure 2- 35. Proposed steric interactions during alkylation References on page 190 139 A similar ratio was obtained in the synthesis of the dimethylamido complex 2h (2.6:1). However, when the incoming group is large (i.e., PhCH2MgCl, PhCMe2CH2MgCl or {Me3Si}3SiLi#3thf), rotation about the N-CI>i0 bond is inhibited and the original meso configuration is retained. A similar mechanism is proposed to account for the formation of the meso rotamer as the only product from the reaction of complex 3h with excess Me3SiCl. Again, the isomerization is believed to take place from an octahedral transition state. In this case, rotation about the N-Cipjo bond to give the meso rotamer takes place to relieve strain due to strong steric interactions between one of the rm-butyl groups in the rac rotamer and the incoming Me3Si fragment (Figure 2- 36,1). (I) (») Figure 2- 36. Proposed steric interactions in the transition state 2.3 Alkyl diamido complexes As described in chapter one, the addition of solid 2,6-bis(bromomethyl)pyridine to a large excess of H2NR (R = Cy, 'Pr, CH'Pr2, 'Bu, CH2CH2NMe2) in hexanes at room temperature affords the oily diamines 2,6-(HRNCH2)2NC5H3 {(iPAP)H2 (lj) R = Pr; (CyAP)H2 (lk) R = Cy; (LiAP)H2 (II) R =CH'Pr2; (tBAP)H, (lm) R= 'Bu; (DMEAP)H2 (In) R = CH2CH2NMe2} References on page 190 140 in quantitative yield(eq. 17). Compounds lj-n can be prepared on a scale of 10-15 g as colorless oils. RT/C6H14 r,—{ H (17) -RNH3Br \ 0) R = 'Pr (k) R = Cy (I) R = CH'Pr2 (m) R = feu (n) R = CH2CH2NMe2 The diamines lj-n react rapidly with Zr(NMe2)4 at room temperature to give the mixed amide complexes 2j-n (eq. 18). Compounds 2j-l can be isolated in nearly quantitative yield as bright yellow crystalline solids. The bis(dimethylamido) complexes 2m-n are too soluble to be isolated and were used without further purification. R / n RT/Toluene g—L \ >NMe2 (18) / \ + Zr(NMe2)4 N'H R (k)R = Cy (j) R = 'Pr NMe2 (I) R = CH'Pr2 1j-n (m)R = teu 2j-n (n) R = CH2CH2NMe2 The 'H NMR spectra of complexes 2j-n display a single sharp resonance for the ligand methylene protons and a singlet for the dimethylamido fragments consistent with C2v-symmetry. Interestingly, the methine protons (NCH) in complex 2j appear as a septet at an unusually high chemical shift (4.45 ppm). In a similar way, the methine protons in complex 2k (8 3.87) and 21 (8 3.25) also appear at low field (vide infra). The 'H NMR spectrum of complex 2n displays a singlet for the ligand CH2CH2NMe2 groups at 2.23 ppm; for comparison, these same protons References on page 190 141 appear at 2.02 ppm for the diamine In. Moreover, the 'H NMR spectrum for complex 2n remains unchanged from -80 °C to +80 °C suggesting that the amine functionalities are not interacting with the zirconium atom. The dichloride complexes 3j-n are formed in good yield from the reaction of complexes 2j-n and excess Me3SiCl at room temperature (eq. 19). RTVToluene + xs Me3SiCI t, J»» 6 -2 Me3SiNMe2 2 0') R = 'Pr (k) R = Cy (I) R = CH'Pr2 _. (m) R = fBu J*n (n) R = CH2CH2NMe2 J" Complexes 3j-m can be crystallized from CH2C12 as white crystalline solids. The high solubility of complex 3n limited its purification. Again, spectral data for complexes 3j-n are consistent with meridional coordination of the pyridine-diamide ligand. The addition of 2.5 equivalents of MeMgBr to the dichloride complexes 3j-n affords the dimethyl derivatives 5j-m in good yield (eq. 20) as bright yellow solids. R / •N / \\ \ ,^CI -30-c/Et2o j-( \ ^Me (20) f N—+ 2.5 MeMgBr • "N\ (k) R = Cy R (I) R = CH'Pr2 3j.n (m) R = teu The C2v-symmetry of complexes 5j-m is evidenced by a single sharp resonance ('H NMR) for the ligand methylene protons (NCH2). The 'H and 13C{ !H} NMR spectra of complex References on page 190 142 5j display a Zr-C//3 resonance at 8 0.34 ppm and a Zr-CH3 at 8 31.26 ppm. Similar resonances are observed for complexes 5k-m and other related complexes23,80-83 The ligand isopropyl methine protons (CHMe2) appear at an unusually high chemical shift (septet at 8 4.97 ppm) in 'H NMR spectrum of complex 5j. In comparison, a chemical shift of 5.04 ppm is obtained with the electronegative chloride substituents while the 7t-donating dimethylamido substituents result in a chemical shift of 4.45 ppm. A similar behavior is observed for complexes 5k and 51. As a result of the meridional coordination of the ligand, the ligand methine protons are directed in between the substituents in the equatorial plane of a trigonal bipyramidal structure. It would appear that the equatorial substituents strongly influence the chemical environment of the methine protons. The possibility of a {3-hydrogen agostic interaction with the 10b,orbital (dxy) is dismissed based on the observed 'J^ coupling constant of 129 Hz. In comparison, a lTCH coupling constant of 131 Hz was observed for the diamine lk. The solid state structure of complex 5k was determined by X-ray crystallography. The complete crystallographic data set can be found in the Appendix. The molecular structure of complex 5k can be found in Figure 2- 37 and relevant bond distances and angles in Table 2- 7. Table 2- 7. Selected Bond Distances (A) and Angles C) for Complex 5k Bond Distances Zr-N(l) 2.076 (3) Zr-€(20) 2.272 (4) Zr-N(2) 2.332 (3) Zr-C(21) 2.272 (4) Zr-N(3) 2.073 (3) Bond Angles N(3)-Zr-N(l) 138.36 (11) N(2)-Zr-C(21) 124.99 (13) N(2)-Zr-C(20) 130.92 (13) C(20)-Zr-C(21) 104.1 (2) References on page 190 143 Figure 2- 37. Molecular structure of complex 5k from X-ray analysis References on page 190 144 The molecular structure of complex 5k is very similar to that of complex 5b. It can best be described as a distorted trigonal bipyramid with the amide nitrogen atoms {N(l) and N(3)} occupying the axial positions (Figure 2- 37). The Zr-amide and Zr-Me distances are comparable to those observed in complex 5b and other zirconium-amido complexes8>84-88. The methine carbons are sp'-hybridized as evidenced by the C-H bond distances (0.963 A and 1.021 A) and N-C-H bond angles (105.9° and 105.3°). The solid state structure of complex 5m was determined by X-ray crystallography. The complete crystallographic data can be found in the Appendix. The molecular structure of complex 5m can be found in Figure 2- 38 and relevant bond distances and angles in Table 2- 8. Table 2- 8. Selected Bond Distances (A) and Angles (°) for Complex 5m' BondDistances Zr(l)-N(l) Zr(l)-N(2) Zr(l)-N(3) 2.118 (2) {2.106 (2)} Zr(l)-C(16) 2.290 (2) {2.297 (3)} Zr(l)-C(17) 2.115 (2) {2.106 (2)} 2.290 (3) {2.281 (3)} 2.247 (3) {2.281 (3)} Bond Angles N(l)-Zr(l)-N(3) 141.29 (8) {141.01 (13)} C(16)-Zr(l)-C(17) N(2)-Zr-C(16) 121.08 (10) {122.24 (8)} Zr(l)-N(l)-C(4) N(2)-Zr-C(17) 119.79 (9) {122.24 (8)} Zr(l)-N(3)-C(12) 119.13 (12) {115.5 (2)} 123.5 (2) {123.9 (2)} 123.6 (2) {123.9 (2)} a, numbers in brackets for second asymmetric molecule References on page 190 145 Figure 2- 38. Top, Molecular structure of complex 5m. Two asymmetric molecules were located in the unit cell; Bottom, core of the C2y-symmetric molecule References on page 190 146 Two asymmetric molecules were located in the unit cell. The Zr-amide and Zr-Me bond distances in both molecules are comparable to those observed in other dimethyl derivatives bearing the pyridine-diamide ligand (5b and 5j). The Zr-N-C angle is about 7.5° larger than the one observed for complex 5j, consistent with the larger ferf-butyl group (Figure 2- 39). Interestingly, one of the asymmetric molecules has C2-symmetry as evidenced by the C2 axis of rotation along the Zr-Npvridine bond and the absence of any mirror plane. Figure 2- 39. Variation of the Zr-N-C angle X-ray analysis using a different crystal of the dimethyl derivative showed C1/CH3 (1:2) disorder at one of the equatorial positions (5m'). The remaining atoms did not show any disorder. This was interpreted as a result of cocrystallization of the dimethyl and methylchloride derivatives with 66.6 % and 33.4 % respective occupancies. The disordered structure (5m') is shown in Figure 2- 40 and relevant bond distances and angles in Table 2- 9. Table 2- 9. Selected Bond Distances (A) and Angles (') for 5m' Bond Distances Zr-N(l) 2.099 (3) Zr-N(3) 2.105(3) Zr-C 2.225 (9) Zr-N(2) 2.277 (2) Zr-C(l) 2.305 (4) Zr-Cl 2.549 (4) Bond Angles N(l)-Zr-N(3) 141.56 (10) N(2)-Zr-C 127.2 (3) C(l)-Zr-C 115.2 (3) N(2)-Zr-C(l) 117.55 (12) N(2)-Zr-Cl 121.64(13) C(l)-Zr-Cl 120.8 (2) References on page 190 147 Core of the dimethyl fragment Core of the mono(methyl) fragment Figure 2- 40. Molecular structure of complex Sm' from X-ray crystallography References on page 190 148 (tBAP)ZrMe2 structure from 5m N N \ 2.118 \ \ \ 121.08 /2.115 ^ M ^ V_>^Me / / 119.79 N N (tBAP)ZrMe2 structure from 5m' N N \ 2.099 \ I I 127.2 /2.IO5 MS V * V_>Me / / 117.55 N N Figure 2- 41. Comparison between the structure of 5m and 5m' The bond distances in the molecular structure of the dimethyl derivative portion of the analysis are comparable (Figure 2- 41) to those obtained from the structure previously described (Figure 2-38 and Table 2- 8). Attempts to synthesis the mono(methyl) derivative were unsuccessful. The reaction of the dichloride precursor 3m with 1 equivalent of methyl Grignard affords a 50 % yield of the dimethyl derivative 5m. 2.3.1 Other alkyl complexes The reaction of the dichloride complex 3m with 2 equivalents of PhCH2MgCl affords the dibenzyl derivative (tBAP)Zr(CH2Ph)2 6m in good yield (eq. 21). References on page 190 149 ,'Bu zfBu (21) The temperature independent (-80 °C to +80 °C) 'H NMR spectrum of complex 6m displays a single sharp resonance for the ligand methylene protons (NCW2) and one benzyl C/72Ph signal. This is consistent with a complex with C2v-symmetry and two equivalent benzyl groups. It is not possible to determine if rapid ri'-ri2 exchange of the benzyl groups is taking place. The addition of 2 equivalents of EtMgCl to the dichloride complex 3j affords the diethyl derivative 19j in good yield (eq. 22). Again, spectroscopic data are consistent with a complex with C2v-symmetry. Complex 19j decomposes slowly at 80 °C in C6D6 (48 hours) yielding a mixture of intractable compounds {no ethylene or free diamine (lj) were detected by 'H NMR spectroscopy}. This differs significantly from what has been observed with the dibutyl and dipropyl complexes bearing the 2,6-diisopropylphenyl substituents on the amides. The protons of the isopropyl groups of the ligand cannot get close enough to the metal center for C-H bond activation. Assuming that the first step in the thermolysis of both systems is similar (Scheme 2-6), the proposed alkylidene species or Zr^-olefin transition state is not stabilized and decomposes. (22) References on page 190 150 The reaction of 1 equiv of 'PrMgCl with complex 3j affords the mono(isopropyl) derivative 20j (eq. 23). (23) The !H NMR spectrum for complex 20j displays the expected AB quartet for the ligand methylene protons (NCHAHB) and two doublets for the ligand isopropyl methyl groups consistent with Q-symmetry. The solid state structure of complex 20j was determined by X-ray analysis. The complete crystallographic data can be found in the Appendix. The molecular structure of complex 20j can be found in Figure 2- 42 and relevant bond distances and angles in Table 2- 10. The two amide nitrogens occupying the axial positions of a distorted trigonal bipyramid. The zirconium atom is located 0.028 A above the plane formed by the three nitrogen atoms. The distortion may take place in order to minimize steric interactions between the isopropyl groups of the ligand and the isopropyl group attached to the metal. The Zr-amide bond distances are similar to those already observed for related complexes (5b, 5k, 5m and 5m'). The short Zr»»C(15) contact of 3.06 A and the Zr-C(14)-C(15) angle of 106.7 (2)° may be a result of agostic interaction. Moreover, C(14) significantly deviates from tetrahedral geometry as indicated by the large Zr-C(14)-C(16) angle of 116.9 (2)°. References on page 190 References on page 190 152 Table 2- 10. Selected Bond Distances (A) and Angles (') for complex 20j BondDistances Zr-N(l) 2.053 (2) Zr-C(14) 2.255 (3) Zr-N(2) 2.304 (2) C(14)-C(15) 1.523 (4) Zr-N(3) 2.059 (2) C(14)-C(16) 1.523 (4) Zr-Cl 2.445 (7) Zr«««C(15) 3.06 Bond Angles N(3)-Zr-N(l) 139.10(8) Zr-C(14)-C(15) 106.7(2) N(2)-Zr-Cl 137.00 (5) Zr-C(14)-C(16) 116.9(2) N(2)-Zr-C(14) 114.48(8) C(15)-C(14)-C(16) 111.5(3) C(14)-Zr-(C1) 108.48 (7) As noted for complex 19j, the thermolysis of complex 20j (C6H6, 80 °C, 48 hours) also yields a mixture of intractable complexes. No propylene was detected by 'H NMR spectroscopy. Complex 20j does not decompose when heated (110 °C, 12 hours) in the presence of excess PMe3. 2.4 Polymerization The polymerization of ethylene by selected pyridine diamide complexes was studied and the results are summarized in Table 2- 11. The polymerization reactions were initiated at approximately 60 °C resulting in a rapid 10-25 °C exotherm. After the desired time, a HC1 -MeOH mixture was added to terminate the polymerization reaction. Catalysts 3a, 5a and 6a yield polyethylene with a number averaged molecular weight around 1000 g/mol (this correspond to approximately 35 repeating units)135. Assuming that all the catalyst is active, each metal centre initiates about 800 polymer chains. As a result, most of the polymer chains are formed by a cationic hydride species generated by chain termination via 0-hydrogen elimination. This indicates that the active catalytic centres are similar for all three References on page 190 153 complexthat chain-end effects are negligible. Thus, the difference in acdvides likely arise from the difference in cadon-anion interactions. Table 2- 11. Ethylene polymerization results* 1 Catalyst Precursor Cat. T time (xl03mmol) (°C) (sec) Yield P.E. (S) Activityb (x 10"3) Nc 1 Cp2ZrCl2 8.21 58 180 30.70 74.8 (5) 1.00 (1 2 (BDPP)Zr(CH2Ph)2 (6a) 13.71 57 150 11.13 19.5 (5) 0.26 (1 3 (BDPP)Zr(CH2Ph)2 (6a) 13.71 60 120 9.85 21.6 (5) 0.29 (1 4 (BMBP)Zr(CH2Ph)2 (6h) 11.89 60 90 7.85 26.4 (5) 0.35 (1 5 (BMBP)Zr(CH2Ph)2 (6h) 19.31 60 120 16.71 26.0 (5) 0.35 (1 6 (tBAP)Zr(CH2Ph)2 (6m) 15.36 60 120 0 0 0 7 (BDPP)ZrMe2 (5a) 12.13 60 105 5.91 16.7 (5) 0.22 (1 8 (BDPP)ZrMe2 (5a) 20.80 60 120 11.88 17.1 (5) 0.23 (1 9 (BDPP)ZrCl2 (3a) 12.95 60 120 6.40 14.8 (5) 0.20 (1 10 (BDPP)ZrCl2 (3a) 9.71 60 120 5.07 15.7 (5) 0.21 (1 11 (BDPP)Zr(CH2Ph)2 (6a)a 6.86 60 90 6.30 36.8 (5) 0.49 (1 12 (BDPP)Zr(CH2Ph)2 (6a)a 9.60 60 120 11.90 37.2 (5) 0.50 (1 14 (BDPP)Zr(CH,Ph)1 (6a)d 8.23 60 120 3.45 12.6 (5) 0.17 (1 Reaction conditions: solvent = heptane (200 mL); Cocatalyst = MAO, 5000 equivalents; P = 100 Psi of ethylene; a, polymerization done in the presence of 30 g of 1-hexene; b, g polyethylene mmol cat.'1 h'1; c, activity vs Cp2ZrCl2; d, solvent = toluene (200 mL). ¥: selected molecular weights less than 1000 g/mol 2.4.1 Counterion effect When toluene solutions of Cp2ZrCl2 are treated with MAO, a fast, initial ligand exchange reaction generates primarily the monomethyl complex Cp2ZrMeCl; with time, the dimethyl References on page 190 154 complex Cp2ZrMe2is formed I36'!37. A methyl or chloride fragment is then abstracted by an Al centre to generate a cationic zirconium species stabilized by the weakly coordinating CH3/C1-MAO" anion. The low coordinating capability of the anion in this ion pair is crucial for catalytic activity ^3^. The interaction must be weak enough to allow an olefin to displace the anion from the coordination sphere of the zirconium. Interestingly, the addition of AlMe3 and AlEt3 has been shown to stabilize cationic catalysts by formation of A1R3 adducts54,139 The activity of the dichloride complex (3a) is slightly less than that of the dimethyl derivative (5a) (Table 2- 12). Higher coordinating ability of the aluminate anion bearing a chloride group instead of a methyl group may explain the difference in activity. The activity of the dibenzyl complex (6a) is much higher than that of the dimethyl or dichloride complexes. It was noted earlier that the reaction of complex 6a with B(C6F5)3 affords a cationic benzyl derivative with what appears to be rf-coordination of the benzylborate anion (23a, eq. 9). A similar interaction between the PhCH2-MAO' anion and the cationic zirconium complex is proposed. The weakly coordinating anion stabilizes the catalytic centre and is displaced easily by the ethylene monomer. However, it is important to keep in mind that the activation of the dichloride complex requires extra steps to obtain the active species (Scheme 2- 7). As a result, complex 3a may take longer to form the cationic complex and appear to ba a less active catalysts. On the other hand, the activity of the dibenzyl derivative 6a is much greated than that of complex 5a. The bulky benzyl groups should slow down the activation of complex 6a relative to that of complex 5a. Again, this is consistent with cation-anion interactions being the key factor determining the activity of this class of catalysts. References on page 190 155 Me Me ^ K\ L"M\ / / Me Me LnMv • LnM \ \ \^ \ \ Cl Me Scheme 2- 7. Reaction of MAO with dichloride complex Table 2- 12. Counter-ion effect Catalyst Solvent Activity (g mmol cat"1 h"')a (BDPP)ZrCl2 (3a) Heptane 15.2 x 103 (BDPP)ZrMe2 (5a) Heptane 16.9 x 103 (BDPP)Zr(CH2Ph)2 (6a) Heptane 20.5 x 103 (BDPP)Zr(CH2Ph)2 (6a) Toluene 12.6 x 103 Cp^ZrCU Toluene 74.8 x 103 a : average of two experiments It is noteworthy that a large excess of toluene inhibits the polymerization and a lower activity is obtained. In this case, the toluene may compete with ethylene for the available coordination site. However, the lower activity may also be a result of better charge separation between the cadon and anion when toluene is used as the solvent140-142 2.4.2 Ligand effect The activity of the me^o-(BMBP)Zr(CH2Ph)2 (6h) is about 25% higher than that of complex 6a (Table 2- 13). The 2,6-diisopropylphenyl substituents in complex 6a protects the metal on both sides of the N3Zr plane (Figure 2- 43, I). On the other hand, the tert-butyl substituents in complex 6h are both located on the same side of the N3Zr plane in a meso structure (Figure 2- 43, II). Assuming that the meso structure persists throughout the References on page 190 156 polymerization, the metal centre is well protected on one side and the other face is left open. Consequently, olefin coordination is facilitated and a higher activity is observed. The rac isomer is also more open than complex 6a (Figure 2- 43, III) and it is not possible to confirm that the meso structure is retained under polymerization conditions. Interestingly, complex 6m does not catalyze the polymerization of ethylene (Table 2- 13). It would appear that this alkyl ligand does not efficiendy stabilize the metal centre and decomposition of the active complex occurs. Table 2- 13. Ligand effect Catalyst Activity (g mmol cat"1 h"')a (BMBP)Zr(CH2Ph)2 (6h) 26.2 x 103 (BDPP)Zr(CH2Ph)2 (6a) 20.5 xlO3 (fBAP)Zr(CfTPh), (6m) 0 average of two experiments Figure 2- 43. Steric protection 2.4.3 Co'polymerization The polyethylene obtained with complex 6a contains a small number of butyl chain (Table 2- 14). This branching is a result of insertion of oc-olefin formed by (3-hydrogen elimination of the growing polymer chain. Interestingly, no increase in the branching is observed when the References on page 190 157 polymerization is carried out in the presence of 1-hexene. This indicates that 1-hexene is not incorporated in the polymer chain. However, the activity nearly doubles. This is interpreted as a result of stabilization of the active catalytic species by coordinated 1-hexene. The dibenzyl derivative does not efficientiy polymerize neat 1-hexene and a mixture of oligomers (n = 3 to 5) is obtained after 24 hours at 60 °C. Table 2- 14. Ethylene/1-hexene co-polymerization Catalyst Monomers Activity (g mmol cat'1 h"1)3 Branching (/1000 CH,) (BDPP)Zr(CH2Ph)2 (6a) Ethylene 20.5 x 103 21 (BDPP)Zr(CH2Ph)2 (6a) Ethylene/1 -hexeneb 37.0 x 103 22 (BDPP)Zr(CH,Ph), (6a) 1-hexene 0 n.a. a : average of two experiments; b : 30 g of 1-hexene were added to the reaction mixture References on page 190 158 3 Conclusions A high yield route to pyridine-diamide complexes of zirconium has been demonstrated. The availability of substituted anilines and alkylamines provides an opportunity to vary the sterics with litde change to the electronic environment about the metal. The coordination geometry of the pyridine-diamide ligand system is very similar to a metallocene (Cp2ZrX2). The frontier orbitals of this fragment resemble those of a metallocene (la,, b2 and 2a,). A ligand centered non-bonding pair of electrons gives rise to an unusually low electron count at zirconium. As a result, pyridine-diamide complexes of zirconium are expected to be more electrophilic than metallocene complexes. A series of ortho-substituted aryl diamide complexes of zirconium have been prepared in high yield. Depending on the size of the ortho substituent on the aryl group, rotameric isomers, derived from restricted rotation about the N-Cipso bond, can be observed spectroscopically and the barriers to isomerization measured. In the case of the 2-phenylaryl moiety, rapid isomerization is observed at all temperatures regardless of the substituents bound to zirconium in the equatorial plane. The 2-isopropylaryl substituted complexes exhibit fluxional behavior with the low temperature limiting 'H NMR spectra showing resonances for species consistent with meso and rac rotamers. In contrast, the 2-terf-butylaryl derivatives are 'locked' as five coordinate species but can isomerize during metathesis reactions at the metal center. The 2-isopropyl-6-methyl complexes are also locked, however, the rotameric ratios remain the same in all derivatives of this ligand system. Pyridine-diamide complexes of zirconium bearing the 2,6-diisopropyl substituents are active catalysts for the polymerization of ethylene. The dibenzyl derivative is the most active species. This is interpreted to be a result of T)6-coordination of the benzyl-MAO' anion which stabilizes the catalytic complex or prevents p-hydride elimination which leads to catalyst deactivation. The more open coordination sphere with complexes bearing the ortho-'e"butyl substituents results in a higher activity. References on page 190 159 4 Experimental Details General Details. See chapter one for general details. (BDPP)H2 (la), (BDMP)H2 (lc), (iPAP)H2 (lj), (CyAP)H2 (lk) and (tBAP)H2 (lm) were prepared as described in chapter one. The zirconium(IV) chloride was purchased from Alfa and used as received. The 2-isopropyl-6-methylaniline, 2-fer?-butylaniline, 2-phenylaniline, 2-isopropylaniline, 2,4,6-trichloroaniline, 2,4,6-tribromoaniline were purchased from Aldrich and distilled under reduced pressure before use. The 2,4-dimethyl-3-aminopentane, 2-dimethylamino-ethylamine, ethylmagnesium bromide, propylmagnesium chloride, isopropylmagnesium chloride and butylmagnesium chloride were purchased from Aldrich and used as received. The (SiMe3)3SiLi(thf)3134, ZrCl2[N(SiMe3)2]280 and Zr(NMe2)4]-4 were synthesised using previously reported syntheses. 2,6-(RHNCH2)2-NC5H3, (R = 2,6-diethyIphenyI), (BDEP)H2 (lb). A THF (150 mL) solution of LiNHR (10.40 g, 67.02 mmol) was added slowly to a stirring THF (100 mL) solution of 2,6-bis(bromomethyl)pyridine (8.876 g, 33.50 mmol) at -78°C. The mixture was warmed to room temperature and stirred for 12 h. The solution was quenched with a saturated NaHC03 solution (lOOmL) and extracted with dichloromethane. The solvent was removed in vacuo to give a yellow oil (lb) which was used as isolated (9.753 g, 24.29 mmol, 73 %). 'H NMR 5 7.10-6.90 (m, 6H, Ar and py), 6.80 (d, 2H, py), 4.35 (br s, 2H, NH), 4.19 (s, 4H, NC//2), 2.72 (q, 8H, C#2CH3), 1.21 (t, 12H, CH2C//3). 13C{'H} NMR 5 148.93, 145.77, 136.86, 136.36, 127.17, 123.20, 120.27, 56.44, 25.10, 15.17. MS (EI) m/z 401.284 (M+). Calcd for C27H35N3: 401.283. 2,6-(RHNCH2)2NC5H„ (R = 2,4,6-trichIorophenyI), (TCPP)H2 (Id). The preparation of compound Id is identical to that of lb. LiNHR (1.030 g, 5.089 mmol) and 2,6-bis(bromomethyl)pyridine (0.674 g, 2.544 mmol) gave white crystalline Id (0.580 g, 1.169 mmol, 46 %). 'H NMR 8 6.95 (s, 4H, Ar), 6.93 (t, IH, py), 6.57 (d, 2H, py), 5.53 (br t, 2H, References on page 190 160 NH), 4.42 (d, 4H, NCH2). 13C{'H} NMR 8 153.38, 142.18, 136.87, 128.69, 125.72, 125.11, 120.21, 52.00. MS (EI) m/z 498.915 (M+). Calcd for C19H13N335C1337C13: 498.915. 2,6-(RHNCH2)2NCsH3, (R = 2,4,6-tribromophenyl), (TBPP)H2 (le). The preparation of compound le is identical to that of lb. LiNHR (2.540 g, 7.565 mmol) and 2,6-bis(bromomethyl)pyridine (1.004 g, 3.789 mmol) gave white crystalline le (1.875 g, 2.458 mmol, 65 %). Compound le is thermally unstable and decompose to a dark brown oil within days at room temperature. 'H NMR 8 7.34 (s, 4H, Ar), 6.95 (t, IH, py), 6.65 (d, 2H, py), 5.44 (br t, 2H, NH), 4.41 (d, 4H, NCH2). UC{XH} NMR 8 165.25, 144.86, 136.87, 135.14, 120.32, 116.50, 113.41, 52.65. MS (EI) m/z 762.614 (M+). Calcd for C19H13N379Br381Br3: 762.615. 2,6-(RHNCH2)2NC5H„ (R = 2-phenylphenyI), (BPhP)H2 (If). The preparation of compound If is identical to that of lb. LiNHR (5.144 g, 29.4 mmol) and 2,6-bis(bromomethyl)pyridine (3.890 g, 14.7 mmol) gave a yellow oily liquid lb (6.000 g, 13.6 mmol, 93 %). 'H NMR 8 7.50 (d, 4H, m Ar/Ph), 7.40-7.09 (m, 10H, Ar/Ph), 6.97 (t, IH, py), 6.80 (t, 2H, Ar/Ph), 6.73 (d, 2H, Ar/Ph), 6.60 (d, 2H, Ar), 5.15 (t, 2H, NH), 4.08 (d, 4H, NCH2). 13C{'H) NMR 8 158.28, 145.17, 140.31, 136.79, 130.61, 129.84, 129.16, 128.17, 127.39, 119.27, 117.64, 111.26, 49.25. MS (EI) m/z 441.220 (M+). Calcd. for C31H27N3: 441.220. 2,6-(RHNCH2)2NCsH3, (R = 2-isopropylphenyl), (BMPP)H2 (lg). The preparation of compound lg is identical to lb except for the work up. LiNHR (5.335 g, 37.4 mmol)) and 2,6-bis(bromomethyl)pyridine (5.000 g, 18.9 mmol) yield a white solid. The solid was dissolved in a minimal amount of ether, hexanes added until the solution was cloudy, and cooled to -30 °C. A white crystalline solid (lg) was isolated by filtration and dried under vacuum (4.500 g, 12.0 mmol, 63 %). 'H NMR 8 7.18 (dd, 2H, Ar), 7.11 (dd, 2H, Ar), 6.97 (m, IH, py), 6.84 (td, 2H, Ar), 6.77 (d, 2H, py), 6.62 (dd, 2H, Ar), 4.77 (br s, 2H, NH), 4.29 (s, 4H, NCH2), 2.87 (sept, 4H, CHMe2), 1.23 (d, 12H, CHMe2). ,3C{'H} NMR 8 158.68, 144.98, References on page 190 161 136.94, 132.43, 127.21, 125.31, 119.77, 118.09, 111.33, 49.61, 27.70, 22.49. MS (EI) m/z 373.252 (M+). Calcd. for C25H31N3: 373.252. 2,6-(RHNCH2)2NCsH3, (R = 2-*-butyIphenyl), (BMBP)Hj (lh). The preparation of compound lh is identical to that of lg. LiNHR (5.865 g, 37.8 mmol) and 2,6-bis(bromomethyl)pyridine (5.000 g, 18.9 mmol) gave a white crystalline solid lh (5.820 g, 14.4 mmol, 76 %). 'H NMR 8 7.35 (d, 2H, Ar), 7.16 (dd, 2H, Ar), 7.02 (td, 1H, py), 6.84 (d 2H, Ar), 6.82 (t, 2H, py), 6.628 (d, 2H, Ar), 4.24 (br s, 2H, NH), 4.32 (s, 4H, NCtf2), 1.49 (s, 18H, r-Bu). 13C{'H} NMR 8 158.39, 146.24, 137.04, 133.55, 54.52, 55.33, 54.48, 56.22, 49.82, 34.41, 30.08. MS (EI) m/z 401.283 (M+). Calcd. for C27H35N3: 401.283. 2,6-(RHNCH2)2NC5H3, (R = 2-methyl-6-isopropyIphenyl), (MPPP)H2 (li). The preparation of compound li is identical to that of lg. LiNHR (7.750 g, 49.9 mmol) and 2,6-bis(bromomethyl)pyridine (5.000 g, 18.9 mmol) gave a white crystalline solid li (4.910 g, 12.2 mmol, 65 %). 'H NMR 8 7.13 (d, 2H, Ar), 7.03-7.00 (m, 5H, py/Ar), 6.75 (d, 2H, py), 4.34 (s, 2H, NH), 4.18 (s, 4H, NCH2), 3.45 (sept, 2H, C//Me2), 2.31 (s, 6H, Me), 1.21 (d, 12H, CHMe2). 13C{'H} NMR 8 159.01, 145.46, 141.45, 136.75, 131.21, 128.88, 124.13, 123.39, 120.29, 55.33, 27.99, 24.16, 19.03. MS (EI) m/z 401.283 (M+). Calcd. for C27H35N3: 401.283. 2,6-(RHNCH2)2NC5H3, (R = diisopropylmethyl), (LiAP)H2 (11). Solid 2,6-bis(bromomethyl)pyridine (1.000 g, 3.774 mmol) was added to a solution 2,4-dimethyl-3-aminopentane (4.350 g, 37.75 mmol) in hexanes (50mL). The solution got warm and a white solid started to form within minutes. The solution was allowed to stir for 12 hours at 23 °C and was quenched with lOOmL of a saturated aqueous NaHC03 solution and extracted with CH2C12. The solvent was removed in vacuo to yield a light yellow liquid 11 (1.220 g, 3.657 mmol, 97 %). 'H NMR 8 7.16 (t, 1H, py), 6.99 (d, 2H, py), 3.97 (s, 4H, NCH2), 1.99 (t, 2H, NCtf'Pr2), 1.74 (d of sept, 4H, C//Me2), 0.98 (d, 12H, CUMe2), 0.95 (d, 12H, CHMe2). 13C{'H} NMR 8 References on page 190 162 160.21, 136.45, 120.24, 69.52, 57.58, 31.26, 21.15, 18.43. MS (EI) m/z 332.307 (M+). Calcd for C21H38N3: 332.307. 2,6-(RHNCH2)2NC5H3, (R = 2-dimethylaminoethyl), (DMEAP)H2 (In). The preparation of compound In is identical to that of 11. 2,6-bis(bromomethyl)pyridine (2.500 g, 9.436 mmol) and 2-dimethylamino-ethylamine (16.64 g, 188.8 mmol) gave a light yellow liquid In (2.192 g, 7.844 mmol, 83 %). 'H NMR 5 7.06 (t, 1H, py), 7.03 (d, 2H, py), 3.89 (s, 4H, NC#2), 2.85 (br s, 2H, NH), 2.61 (t, 4H, CH2), 2.31 (t, 4H, CH2), 2.02 (s, 6H, NMe2). I3C{'H} NMR 5 160.46, 136.58, 120.09, 59.48, 55.72, 47.28, 45.46. MS (EI) m/z 279.243 (M+). Calcd for C15H29N5: 279.242. (BDPP)Zr(NMe2)2 (2a). A toluene solution of Zr(NMe2)4 (1.748 g, 6.534 mmol) was added to a toluene solution (50 mL) of la (2.990 g, 6.532 mmol) at 23 °C. The solution was refluxed for 12 hours. The solvent was removed in vacuo and the resulting solid extracted with hexanes (3 x 50 mL) and filtered through Celite. The volume of the filtrate was reduced to 50 mL and cooled to -30 "C for 12 h. Yellow crystalline 2a was isolated by filtration and dried under vacuum (3.742 g, 5.892 mmol, 90 %). 'H NMR 8 7.20-7.05 (m, 6H, Ar), 6.87 (t, 1H, py), 6.47 (d, 2H, py), 4.81 (s, 4H, NC//2), 3.69 (sept, 4H, C//Me2), 2.53 (s, 12H, N(C//3)2), 1.31 (d, 12H, CHMe2), 1.29 (d, 12H, CHMe2). 13C{'H} NMR 8 163.26, 150.89, 146.28, 137.56, 124.59, 123.73, 117.18, 60.62, 41.51, 28.06, 26.44, 24.69. Calcd for C35H53N5Zr: C, 66.20; H, 8.41; N, 11.03. Found: C, 66.69; H, 8.39; N, 10.77. (BDEP)Zr(NMe2)2 (2b). The preparation of compound 2b is identical to that of 2a. Zr(NMe2)4 (1.000 g, 3.738 mmol) and compound lb (1.500 g, 3.735 mmol) gave yellow crystalline 2b (1.950 g, 3.368 mmol, 90 %). 'H NMR 8 7.21 (d, 6H, Ar), 7.05 (m, 2H, Ar), 6.88 (t, 1H, py), 6.47 (d, 2H, py), 4.69 (s, 4H, NC#2), 2.86 (m, 8H, C//2CH3), 2.58 (s, 12H, N(C//3)2), 1.29 (t, 12H, CH2C//3). 13C{'H}NMR 8 164.07, 152.54, 141.22, 138.63, 126.03, 123.83, 117.30, 62.27, 41.44, 24.39, 15.85. References on page 190 163 (BDMP)Zr(NMe2)2 (2c). The preparation of compound 2c is identical to that of 2a. Zr(NMe2)4 (1.000 g, 3.738 mmol) and compound lc (1.300 g, 3.763 mmol) gave yellow crystalline 2c (1.791 g, 3.425 mmol, 92 %). 'H NMR 8 7.16 (d, 4H, Ar), 6.97 (m, 2H, Ar), 6.90 (t, IH, py), 6.46 (d, 2H, py), 4.63 (s, 4H, NCH2\ 2.58 (s, 12H, N(C//3)2), 2.37 (s, 12H, Me). 13C{'H} NMR 8 164.45, 153.25, 137.54, 135.67, 128.58, 123.34, 117.34, 63.70, 41.32, 18.86. (TCPP)Zr(NMe2)2 (2d). The preparation of compound 2d is identical to that of 2a. Zr(NMe2)4 (1.500 g, 5.607 mmol) and compound Id (2.780 g, 5.544 mmol) gave yellow crystalline 2d (3.020 g, 4.485 mmol, 81 %). 'H NMR 8 7.19 (s, 4H, Ar), 6.88 (t, IH, py), 6.42 (d, 2H, py), 4.62 (s, 4H, NC/Y2), 2.76 (s, 12H, NMe2). 13C{'H} NMR 8 163.58, 151.03, 138.38, 134.44, 128.15, 126.69, 117.47, 62.05, 41.82. (TBPP)Zr(NMe2)2 (2e). The preparation of compound 2e is identical to that of 2a. Zr(NMe2)4 (0.585 g, 2.187 mmol) and compound le (1.668 g, 2.187 mmol) gave yellow crystalline 2e (1.568 g, 1.668 mmol, 76 %). 'H NMR 8 7.59 (s, 4H, Ar), 6.90 (t, IH, py), 6.44 (d, 2H, py), 4.61 (s, 4H, NC/72), 2.73 (s, 12H, NMe2). 13C{'H} NMR 8 163.28, 153.64, 138.29, 124.40, 125.77, 117.45, 114.59, 62.02, 42.01. (BPhP)Zr(NMe2)2 (2f). The preparation of compound 22f is identical to that of 2a. Zr(NMe2)4 (3.635 g, 13.6 mmol) and compound If (6.000 g, 13.6 mmol) gave yellow crystalline 2f (7.715 g, 12.5 mmol, 92%). 'H NMR 8 7.74 (d, 2H, Ar/Ph), 7.71 (d, 2H, Ar/Ph), 7.36-7.32 (m, 4H, Ar/Ph), 7.11-6.98 (m, 8H, Ar/Ph), 6.56 (t, IH, py), 6.00 (d, 2H, py), 4.66 (s, 4H, NCH2), 2.94 (s, 12H, NMe2). 13C{'H} 8 164.67, 153.33, 143.59, 137.46, 135.30, 131.95, 128.45, 128.32, 128.196, 127.76, 126.34, 122.55, 116.93, 63.29, 41.92. (BMPP)Zr(NMe2)2 (2g). The preparation of compound 2g is identical to 2a. Zr(NMe2)4 (2.150 g, 8.03 mmol) and lg (3.000 g, 8.03 mmol) gave 2g as a yellow crystalline solid (4.100 g, 7.44 mmol, 93%). 'H NMR 8 7.41 (dd, 2H, Ar), 7.32 (dd, 2H, Ar), 7.21 (td, 2H, Ar), 1.11 (td, 2H, Ar), 8.87 (t, IH, py), 6.42 (d, 2H, py), 4.93 (s, 4H, NO/2), 3.53 (sept, References on page 190 164 4H, C#Me2), 2.76 (s, 12H, NMe2), 1.29 (d, 12H, CUMe2). uC{lU) 6 164.64, 152.91, 145.71, 137.59, 129.27, 126.32, 126.14, 124.04, 117.34, 67.26, 42.03, 27.29, 25.23. (BMBP)Zr(NMe2)2 (2h). The preparation of compound 2h is identical to 2a. Zr(NMe2)4 (2.150 g, 8.04 mmol) and lh (3.000 g, 8.03 mmol) gave 2h a yellow crystalline solid (3.987 g, 7.24 mmol, 90%). The following data is for both rotamers (meso/rac, 2.6:1). ]H NMR 5 7.48 (t, Ar), 7.24 (t, Ar), 7,07 (t, Ar), 6.90 (t, py), 6.49 (d, py), 4.91 (s, meso NCH2), 4.90 (AB quartet, 2Jm = 20.0 Hz, rac NCtf2), 3.01 (s, meso NMe2), 2.65 (s, rac NMe2), 2.42 (s, meso NMe2), 1.57 (s, rac CMe,), 1.51 (s, meso CMeJ. I3C{'H} 5 163.88, 163.14, 156.07, 154.46, 146.67, 137.73, 132.32, 132.12, 128.90, 127.94, 126.95, 126.76, 124.30, 123.73, 117.25, 68.40, 43.25, 42.15, 41.05, 36.56, 32.64, 32.41. (MPPP)Zr(NMe2)2 (2i). The preparation of compound 2i is identical to 2a. Zr(NMe2)4 (2.671 g, 10.0 mmol) and li (4.010 g, 10.0 mmol) gave 2i as a yellow crystalline solid (3.090 g, 5.34 mmol, 54%). The following data is for both rotamers (meso/rac, 1:1.13). 'H NMR 5 7.27-7.23 (m, Ar/Ph), 7.16-7.05 (m, Ar/Ph), 6.93 (t, py), 6.48 (d, py), 4.68 (AB quartet, 2JHH = 20.3 Hz, rac NCH2), 4.65 (AB quartet, 2JHH = 20.3 Hz, meso NC//2), 4.00 (sept, meso C//Me2), 3.82 (sept, rac C//Me2), 2.88 (s, meso NMe2), 2.57 (s, rac NMe2), 2.32 (s, rac Me), 2.30 (s, meso NMe2), 2.19 (s, meso Me), 1.39 and 1.38 (d, meso CHMe2), 1.32 and 1.29 (d, rac CUMe2). ''Cf'H) 5 164.12, 163.81, 152.39, 152.12, 146.41, 146.38, 137.60, 137.54, 135.37, 135.10, 123.86, 123.77, 117.25, 65.06, 64.92, 42.59, 41.33, 40.08, 27.64, 26.92, 26.76, 24.28, 24.04, 19.16, 19.07. (iPAP)Zr(NMe2)2 (2j). The preparation of compound 2j is identical to that of 2a. Compound lj (0.500 g, 2.259 mmol) and Zr(NMe2)4 (0.604 g, 2.258 mmol) yielded yellow crystalline 2j (0.829 g, 2.079 mmol, 92 %). 'H NMR 5 6.91 (t, 1H, py), 6.54 (d, 2H, py), 4.52 (s, 4H, NC//2), 4.45 (sept, 2H, NC//Me2), 3.22 (s, 12H, NMe2), 4.34 (d, 12H, NCHMe2). 13C{JH} NMR 6 165.89, 136.39, 117.20, 56.32, 50.10 ('JCH = 130 Hz), 44.11, 23.58. References on page 190 165 (CyAP)Zr(NMe2)2 (2k). The preparation of compound 2k is identical to that of 2a. Compound lk (1.000 g, 3.317 mmol) and Zr(NMe2)4 (0.887 g, 3.316 mmol) yielded yellow crystalline 2k (1.428 g, 2.982 mmol, 90 %). 'H NMR 5 6.90 (t, IH, py), 6.55 (d, 2H, py), 4.57 (s, 4H, NC/72), 3.87 (tt, 2H, NC//), 3.22 (s, 12H, NMe2), 1.94 (m, 8H, Cy), 1.66 (m, 10H, Cy), 1.18 (m, 2H, Cy). I3C{'H} NMR 5 166.01, 136.35, 117.11,59.71 ('JCH = 131 Hz), 57.94, 44.30, 34.86, 27.24, 26.94. (LiAP)Zr(NMe2)2 (21). The preparation of compound 21 is identical to that of 2a. Compound 11 (1.000 g, 2.998 mmol) and Zr(NMe2)4 (0.957 g, 3.577 mmol) yielded yellow crystalline 21 (1.390 g, 2.721 mmol, 91 %). 'H NMR 5 6.94 (t, IH, py), 6.56 (d, 2H, py), 4.56 (s, 4H, NC#2), 3.25 (t, 2H, C/7'Pr2), 3.02 (s, 12H, NMe2), 2.14 (d of sept, 4H, CH(C/YMe2)2), 1.18 (d, 12H, CHMe2), 1.01 (d, 12H, CHMe2). 13C{'H} NMR 5 165.62, 136.52, 116.94, 70.81, 58.04, 43.56, 43.45, 30.72, 22.07, 21.49. (tBAP)Zr(NMe2)2 (2m). The preparation of compound 2m is identical to that of 2a. Compound lm (3.500 g, 14.04 mmol) and Zr(NMe2)4 (3.750 g, 14.02 mmol) yielded dark brown liquid 2m (5.925 g, 13.88 mmol, 99 %). Because of its high solubiliy, compound 2m was not isolated and was used in situ. 'H NMR 8 6.81 (t, IH, py), 6.55 (d, 2H, py), 4.70 (s, 4H, NC/Y2), 2.89 (s, 12H, NMe2), 1.47 (s, 18H, CMe3). 13C{'H} NMR 6 166.43, 136.45, 116.91, 59.72, 56.07, 42.53, 31.22. (DMEAP)Zr(NMe2)2 (2n). The preparation of compound 2n is identical to that of 2a. Compound In (0.600 g, 2.147 mmol) and Zr(NMe2)4 (0.575 g, 2.149 mmol) yielded dark brown liquid 2n (0.887 g, 1.942 mmol, 90 %). Because of its high solubiliy, compound 2n was not isolated and was used in situ. 'H NMR 5 6.92 (t, IH, py), 6.56 (t, 2H, py), 4.56 (s, 4H, NC//2), 3.75 (t, 4H, CH2), 3.19 (s, 12H, NAfe2), 2.55 (t, 4H, CH2), 2.23 (s, 12H, NMe2). 13C{'H} NMR 5 165.54, 138.68, 117.09, 64.44, 62.59, 52.33, 46.48, 43.97. References on page 190 166 (BDPP)ZrCl2 (3a). Neat Me3SiCl (5.200 g, 47.86 mmol) was added to a toluene solution (50 mL) of 2a (3.000 g, 4.724 mmol) at 23 °C. The solution was stirred for 12 hours allowing the precipitation of a white solid. The solution was cooled to -30 °C. White crystalline 3a was isolated by filtration and dried under vacuum (2.862 g, 4.632 mmol, 98 %). ]H NMR 8 7.20-7.10 (m, 6H, Ar), 6.76 (t, IH, py), 6.27 (d, 2H, py), 4.81 (s, 4H, NC//2), 3.74 (sept, 4H, C/YMe2), 1.54 (d, 12H, CHMe2), 1.20 (d, 12H, CHMe2). 13C{lH) NMR 8 162.94, 146.03, 138.86, 127.40, 124.72, 117.74, 68.19. 28.59. 27.03. 24.78. (BDEP)ZrCl2 (3b). The preparation of compound 3b is identical to that of 3a. Neat Me3SiCl (2.705 g, 24.90 mmol) and compound 2b (1.434 g, 2.477 mmol) gave white crystalline 3b (1.378 g, 2.453 mmol, 99 %). 'H NMR 8 7.20-7.10 (m, 6H, Ar), 6.86 (t, IH, py), 6.37 (d, 2H, py), 4.63 (s, 4H, NC//2), 2.98 (m, 8H, C//2CH3), 1.29 (t, 12H, CH2C//3). "Cl'H} NMR 8 163.93, 154.80, 141.74, 138.68, 127.12, 126.72, 117.81, 67.20, 24.60, 15.58. (BDMP)ZrCl2 (3c). The preparation of compound 3c is identical to that of 3a. Neat Me3SiCl (9.430 g, 86.80 mmol) and compound 2c (4.538 g, 8.679 mmol) gave white crystalhne 3c (4.021 g, 7.953 mmol, 92 %). 'H NMR 8 7.09 (m, 4H, Ar), 7.03 (m, 2H, Ar), 6.84 (t, IH, py), 6.36 (d, 2H, py), 4.44 (s, 4H, NC/72), 2.46 (s, 12H, Me). 13C{'H} NMR 8 163.01, 153.03, 138.46, 136.24, 129.31, 127.37, 117.70, 65.60, 19.30. (TCPP)ZrCl2 (3d). The preparation of compound 3d is identical to that of 3a. Neat Me3SiCl (5.000 g, 46.02 mmol) and compound 2d (3.025 g, 4.492 mmol) gave white crystalline 3d (2.628 g, 4.005 mmol, 89 %). lU NMR 8 7.12 (s, 4H, Ar), 6.88 (t, IH, py), 6.42 (d, 2H, py), 4.75 (s, 4H, NCtf2). 13C{'H} NMR 8 163.05, 148.76, 138.71, 134.59, 129.45, 117.48, 72.40. (TBPP)ZrCl2 (3e).The preparation of compound 3e is identical to that of 3a. Neat Me3SiCl (0.867 g, 7.980 mmol) and compound 2i (0.750 g, 0.798 mmol) gave white crystalline 3e (0.657 g, 0.712 mmol, 89 %). 'H NMR 8 7.48 (s, 4H, Ar), 6.74 (t, IH, py), 6.25 (d, 2H, References on page 190 167 py), 4.58 (s, 4H, NC//2). Compound 3e is poorly soluble in organic solvents which precludes its convenient characterization by ^Cf'H} NMR spectroscopy. (BPhP)ZrCl2 (3f). The preparation of compound 3f is identical to that of 3a. Neat Me3SiCl (4.000 g, 36.82 mmol) and compound 2f (2.315 g, 3.74 mmol) gave white crystalline 3f (2.152 g, 3.57 mmol, 96 %). 'H NMR 5 8.44 (d, 2H, Ph), 7.90-7.80 (m, 4H, Ph), 7.40-6.90 (m, 12H, Ar/Ph), 6.39 (t, 1H, py), 5.84 (d, 2H, py), 4.54 (s, 4H, NC//2). Compound 3a is poorly soluble in organic solvents which precludes its convenient characterization by 13C{'H} NMR spectroscopy. (BMPP)ZrCl2 (3g). The preparation of compound 3g is identical to 3a. Excess Me3SiCl (3.000 g, 27.61 mmol) and 2g (1.500 g, 2.72 mmol) affords 3g as a beige solid (1.190 g, 2.23 mmol, 82 %). 'H NMR 5 7.98 (br d, 2H, Ar), 7.29 (m, 2H, Ar), 7.15 (m, 4H, Ar), 6.89 (t, 1H, py), 6.34 (d, 2H, py), 4.73 (br s, 4H, NCH2), 3.48 (br sept, 4H, C//Me2), 1.33 (br s, 12H, CHMe2). 13C{'H} (J8-toluene, 80 °C) 8 164.31, 147.20, 146.33, 138.63, 130.34, 127.41, 127.33, 126.74, 117.71, 69.32, 27.60, 25.01. (BMBP)ZrCl2 (3h). The preparation of compound 3h is identical to 3a. Excess Me3SiCl (1.500 g, 13.81 mmol) and 2h (1.000 g, 1.73 mmol) affords 3h as a beige solid (0.860 g,1.54 mmol, 89 %). lH NMR 5 7.95 (d, 2H, Ar), 7.47 (d, 2H, Ar), 7.18 (m, 4H, Ar), 6.81 (t, 1H, py), 6.34 (d, 2H, py), 4.78 (AB quartet, 2Jm = 20.1 Hz, 4H, NC#2), 1.47 (s, 18H, f-Bu). 13C{'H} 5 162.66, 147.23, 146.05, 138.79, 131.46, 131.01, 127.46, 127.16, 117.76, 70.21, 37.09, 33.31. (MPPP)ZrCl2 (3i). The preparation of compound 3i is identical to 3a. Excess Me3SiCl (3.000 g, 27.61 mmol) and 2i (1.700 g, 2.94 mmol) affords 3i as a beige solid (1.327 g, 2.36 mmol, 80 %). The following data is for both rotamers (meso/rac, 1:1.15). 'H NMR (CD2C12) 5 8.04 (t, py), 7.52 (d, py), 7.25-7.09 (m, Ar), 5.06 (AB quartet ^ = 21.3 Hz, NCH2), 5.05 (AB quartet'J^ = 21.3 Hz, NCH2), 3.56 (sept, C//Me2), 3.48 (sept, CtfMe2), 2.35 (s, Me), 2.31 (s, Me), 1.35 (d, CUMe2), 1.32 (d, CHMe2), 1.18 (d, CHMe2), 1.16 (d, References on page 190 168 CHMe2). !3C{'H} NMR (CDC12) 5 164.16, 164.12, 147.52, 147.38, 145.22, 145.19, 141.53, 139.92, 136.18, 136.05, 129.33, 128.74, 128.70, 128.51, 127.41, 126.87, 125.59, 125.21, 124.77, 118.74, 67.20, 67.16, 28.03, 27.91, 27.73, 27.54, 23.81, 23.42, 19.50, 19.46. (iPAP)ZrCl2 (3j). The preparation of complex 3j is identical to that of 3a. Compound 2j (0.750 g, 1.881 mmol) and Me3SiCl (1.000 g, 9.204 mmol) yielded white crystalline 3j (0.558 g, 1.463 mmol, 78 %). 'H NMR 8 6.90 (t, 1H, py), 6.46 (d, 2H, py), 5.04 (sept, 2H, C//Me2), 4.22 (s, 4H, NC//2), 1.26 (d, 12H, CHMe2). 13C{'H} NMR 8 164.76, 137.31, 117.54, 56.55, 47.49, 20.60. (CyAP)ZrCl2 (3k). The preparation of complex 3k is identical to that of 3a. Compound 2k (1.100 g, 2.297 mmol) and Me3SiCl (2.500 g, 10.44 mmol) yielded white crystalline 2k (0.986 g, 2.136 mmol, 93 %). 'H NMR 5 6.89 (t, 1H, py), 6.45 (d, 2H, py), 4.47 (brt, 2H, NC//), 4.25 (s, 4H, NC//2), 2.18 (m, 4H, Cy), 1.83 (m, 4H, Cy), 1.40 (m, 10H, Cy), 1.05 (m, 2H, Cy). 13C{'H} NMR 8 165.02, 137.34, 117.50, 58.16, 56.24, 31.66, 26.83, 26.36. (LiAP)ZrCl2 (31). The preparation of complex 31 is identical to that of 3a. Compound 21 (1.390 g, 2.721 mmol) and Me3SiCl (5.000 g, 46.02 mmol) yielded grey crystalline 31 (1.166 g, 2.282 mmol, 84 %). 'H NMR 8 6.88 (t, 1H, py), 6.42 (d, 2H, py), 4.23 (s, 4H, NC//2), 4.21 (t, 2H, C//Pr2), 2.08 (d of sept, 4H, C//Me2), 1.22 (d, 12H, CWMe2), 1.11 (d, 12H, CHMe2). 'H NMR (CDC13) 8 7.89 (t, 1H, py), 7.42 (d, 2H, py), 4.86 (s, 4H, NC//2), 3.91 (t, 2H, C//'Pr2), 2.11 (d of sept, 4H, C//Me2), 1.13 (d, 12H, CHMe,), 1.08 (d, 12H, CHMe2). 13C{'H} NMR (CDC13) 8 165.15, 138.34, 117.88, 66.00, 59.16, 32.29, 22.9, 21.17. (tBAP)ZrCI2 (3m). The preparation of complex 3m is identical to that of 3a. Compound 2m (5.925 g, 13.88 mmol) and Me3SiCl (10.00 g, 41.75 mmol) yielded grey crystalline 3m (5.120 g, 12.50 mmol, 90 %). 'H NMR 8 6.80 (t, 1H, py), 6.32 (7, 2H, py), References on page 190 169 4.40 (s, 4H, NC/72), 1.68 (s, 18H, CMe3). 13C{'H} NMR 8 166.43, 136.45, 116.91, 59.72, 56.07, 42.53, 31.22. (DMEAP)ZrCl2 (3n). The preparation of complex 3n is identical to that of 3a. Compound 2n (0.887 g, 1.842 mmol) and Me3SiCl (2.500 g, 23.01 mmol) yielded dark brown solid 3n (0.756 g, 1.720 mmol, 94 %). ]H NMR 5 6.90 (t, IH, py), 6.49 (d, 2H, py), 4.51 (s, 4H, NC//2), 3.31 (t, 4H, CH2), 2.93 (br s, 4H, CH2), 2.49 (s, 12H, NMe2). '^{'H} NMR 8 164.10, 136.82, 116.36, 67.95, 64.32, 54.82, 49.42. (BDPP)ZrCl2{HN(SiMe3)2) (4a). To a toluene solution of ZrCl2{N(SiMe3)2}2 (0.100 g, 0.207 mmol) was added a toluene solution (50 mL) of la (0.096 g, 0.210 mmol) at 23 °C. The solution was refluxed for 12 hours. The solvent was removed in vacuo to give a yellow oily solid 4a (0.106 g, 0.136 mmol, 66 %). 'H NMR 8 7.30-7.10 (m, 6H, Ar), 6.98 (t, IH, py), 6.48 (d, 2H, py), 5.20 (AB quartet, 2Jm = 20.0 Hz, 4H, NC#2), 4.06 (sept, 2H, C//Me2), 3.16 (sept, 2H, C/YMe2), 1.57 (d, 6H, CHMe2), 1.46 (d, 6H, CHMe2), 1.38 (d, 6H, CHMe2), 1.07 (d, 6H, CUMe2), 0.27 and 0.16 {s, 18H each, ZrNH(SiM«3)2 and free HN(SiAf>3)2}. (BDPP)ZrMe2 (5a). To a diethylether (25 mL) suspension of compound 3a (0.250 g, 0.405 mmol) was added 2.2 equiv of MeMgBr (0.49 mL, 1.80 M, 0.88 mmol) at 23 "C. The suspension was stirred for 12h. The solvent was remover in vacuo. The resulting solid was extractred with toluene (3 x 10 mL) and filtered through Celite to give a light-yellow solution. The solvent was removed in vacuo, the solid dissolved in a minimum amount of diethylether and cooled to -30 °C for 12 h. White crystalline 5a was isolated by filtration and dried under vaccum (0.207 g, 0.359 mmol, 89 %). 'H NMR 8 7.30-7.20 (m, 6H, Ar), 6.88 (t, IH, py), 6.40 (d, 2H, py), 4.95 (s, 4H, NC/72), 3.84 (sept, 4H, CHMc2), 1.41 (d, 12H, CHMe2), 1.21 (d, 12H, CHMe2), 0.45 (s, 6H, ZrCtf3). ,3C{'H} NMR 8 163.94, 147.12, 137.98, 126.38, 124.44, 117.36, 67.48, 44.71, 28.32, 28.17, 24.18. Anal. Calcd for C33H47N3Zr: C, 68.70; H, 8.21; N, 7.28. Found: C, 69.50; H, 8.57; N, 7.49. References on page 190 170 (BDEP)ZrMe2 (5b). The preparation of compound 5b is identical to that of 5a. Compound 3b (0.400 g, 0.712 mmol) and MeMgBr (0.87 mL, 1.80 M, 1.57 mmol) gave white crystalline 5b (0.307 g, 0.589 mmol, 83 %). 'H NMR 8 7.30-7.20 (m, 6H, Ar), 6.87 (t, 1H, py), 6.45 (d, 2H, py), 4.77 (s, 4H, NCH2), 2.94 (q, 8H, C//2CH3), 1.27 (t, 12H, CH2C//3), 0.29 (s, 6H, ZrC//3). 13C{'H} NMR 8 164.34, 146.73, 142.63, 137.83, 126.60, 126.08, 117.60, 66.41, 42.83, 24.14, 16.17. Anal. Calcd for C29H39N3Zr: C, 66.87; H, 7.55; N, 8.07. Found: C, 66.37; H, 7.71; N, 7.83. (BDMP)ZrMe2 (5c). The preparation of compound 5c is identical to that of 5a. Compound 3c (0.100 g, 0.198 mmol) and MeMgBr (0.24 mL, 1.80 M, 0.432 mmol) gave white crystalline 5c (0.074 g, 0.159 mmol, 80 %). 'H NMR 8 7.16 (m, 4H, Ar), 7.06 (m, 2H, Ar), 6.88 (t, 1H, py), 6.44 (d, 2H, py), 4.58 (s, 4H, NC//2), 2.40 (s, 12H, Me), 0.34 (s, 6H, ZrC//3). nC{lH} NMR 8 164.34. 142.83. 137.56. 136.81. 128.87. 125.47, 117.42, 64.60, 47.88, 18.54. (TCPP)ZrMe2 (5d). The preparation of compound 5f is identical to that of 5a. Compound 3d (0.700 g, 1.067 mmol) and MeMgBr (1.99 mL, 1.34 M, 2.67 mmol) gave white crystalline 5d (0.377 g, 0.613 mmol, 57 %). 'H NMR 8 7.21 (s, 4H, Ar), 6.79 (t, 1H, py), 6.34 (d, 2H, py), 4.62 (s, 4H, NC//2), 0.68 (s, 6H, ZrM<?2). 13C{'H} NMR 8 163.48, 144.86, 138.30, 137.10, 131.11, 117.82, 62.91, 47.38. (TBPP)ZrMe2 (5e). The preparation of compound 5e is identical to that of 5a. Compound 3e (0.150 g, 0.163 mmol) and MeMgBr (0.30 mL, 1.34 M, 0.40 mmol) gave white crystalline 5e (0.112 g, 0.127 mmol, 69 %). 'H NMR 8 7.60 (s, 4H, Ar), 6.81 (t, 1H, py), 6.34 (d, 2H, py), 4.68 (s, 4H, NC//2), 0.77 (s, 6H, ZrMe). nC{lU) NMR 8 163.36, 147.68, 138.41, 135.25, 119.10, 117.86, 62.86, 49.68. (BPhP)ZrMe2 (5f). The preparation of compound 5f is identical to that of 5a. Compound 3f (1.000 g, 1.66 mmol) and MeMgBr (3.70 mL, 0.99 M, 3.67 mmol) gave white References on page 190 171 crystalline 5f (0.625 g, 1.11 mmol, 67 %). 'H NMR 5 8.10 (d, 2H, Ph), 7.73 (d, 4H, Ph), 7.38 (d, 2H, Ar/Ph), 7.31-7.28 (m, 2H, Ar/Ph), 7.15-7.08 (m, 6H, Ar/Ph), 6.99 (m, 2H, Ar/Ph), 6.49 (t, 1H, py), 5.93 (d, 2H, py), 4.62 (s, 4H, NC//2), 0.73 (s, 6H, Zr-Me). 13C{'H} NMR 8 164.02, 148.94, 142.66, 137.59, 136.82, 133.01, 129.06, 128.68, 128.49, 128.17, 126.84, 125.21, 116.97, 64.51, 42.38. Anal. Calcd. for C33H31N3Zr: C, 70.67; H, 5.57; N, 7.49. Found: C, 70.60; H, 5.55; N.7.19. (BMPP)ZrMe2 (5g). The preparation of compound 5g is identical to that of 5a. Compound 3g (0.500 g, 0.94 mmol) and MeMgBr (0.78 mL, 3.0 M, 2.34 mmol) gave white crystalline 5g (0.445 g, 0.90 mmol, 85 %). 'H NMR 8 7.69 (m, 2H, Ar), 7.36 (m, 2H, Ar), 7.20 (m, 4H, Ar), 6.87 (t, 1H, py), 6.38 (d, 2H, py), 4.84 (s, 4H, NCH2), 3.57 (sept, 4H, C//Me2), 1.31, (d, 12H, CHMe2), 0.46 (br s, 6H, Zr-Me). 13C{'H} NMR 8 164.02, 148.50, 147.54, 131.08, 129.27, 127.21, 126.67, 126.29, 117.35, 58.31, 41.23 (Zr-C//3), 27.25, 25.39. Anal. Calcd. for C27H35N3Zr: C, 65.81; H, 7.16; N, 8.53. Found: C, 66.03; H, 7.18; N, 8.68. (BMBP)ZrMe2 (5h). The preparation of compound 5h is identical to 5a. MeMgCl (0.52 mL, 3.0 M, 1.55 mmol) and 3h (0.350 g, 0.62 mmol) gave 5h as a white crystalline solid (0.234 g, 0.45 mmol, 73%). The following data is for both rotamers (meso/rac, 3:1). 'H NMR 5 7.78 (d, Ar), 7.54 (d, Ar), 7.20 (m, Ar), 6.87 (t, py), 6.43 (d, py), 4.91 (AB quartet, 2Jm = 20.7 Hz, meso NC#2), 4.83 (AB quartet, 2Jm = 20.7 Hz, rac NCH2), 1.55 (s, rac r-Bu), 1.49 (s, meso t-Bu), 0.82 (s, meso Zr-Me), 0.62 (s, rac Zr-Me), 0.26 (s, meso Zr-Me). 13C{'H} NMR 8 163.66, 163.21, 149.43, 147.18, 137.90, 133.98, 132.75, 130.93, 127.06, 126.92, 126.02, 125.88, 117.47, 70.03, 69.71, 45.71 (Zr-CH3), 44.73 (Zr-CH3), 39.57, 37.18, 33.34. Anal. Calcd. for C29H39N3Zr: C, 66.87; H, 7.55; N, 8.07. Found: C, 66.64; H, 7.77; N, 7.91. (MPPP)ZrMe2 (5i). The preparation of compound 5i is identical to 5a. MeMgCl (0.75 mL, 3.0 M, 2.23 mmol) and 3i (0.500 g, 0.89 mmol) gave 5i as a white crystalline solid (0.316 g, 0.61 mmol, 69%). The following data is for both rotamers (meso/rac, 1:1.14). 'H References on page 190 172 NMR 5 7.23-7.00 (m, Ar), 6.91 (t, py), 6.45 (d, py), 4.75 (AB quartets 2JHH = 20.8 Hz, NC//2), 4.74 (AB quartets 2JHH = 20.8 Hz, NC/72), 3.90 (sept, CHMe2), 2.38 (s, Me), 2.11 (s, Me), 1.45 (d, CHMe2), 1.43 (d, CHMe2), 1.25 (d, CHMe2), 1.23 (d, CHMe2), 0.45 (s, meso Zr-Me), 0.39 (s, rac Zr-Me), 0.32 (s, meso Zx-Me). "Cf'H} NMR 8 164.23, 164.17, 147.78, 147.75, 147.28, 137.79, 136.43, 129.28, 128.67, 128.51, 125.97, 125.64, 124.54, 117.42, 65.96, 44.35, 43.71, 42.67, 28.63, 28.51, 27.71, 23.75, 23.63, 21.40, 19.09. Anal. Calcd. for C29H39N3Zr: C, 66.87; H, 7.55; N, 8.07. Found: C, 66.79; H, 7.51; N, 8.24. (iPAP)ZrMe2 (5j). The preparation of complex 5j is identical to that of 5a. Compound 3j (0.500 g, 1.311 mmol) and MeMgBr (1.09 mL, 3.00 M, 3.27 mmol) gave white crystalline 5j (0.358 g, 1.051 mmol, 80 %). 'H NMR 8 6.90 (t, IH, py), 6.50 (d, 2H, py), 4.97 (sept, 2H, C//Me2), 4.43 (s, 4H, NCH2), 1.40 (d, 12H, CHMe2), 0.34 (s, 6H, ZrMe). 13C{'H} NMR 8 165.00, 136.56, 117.25, 56.14, 46.34 ('J^ = 129 Hz), 31.26, 21.99. Anal, calcd. for C15H27N3Zr: C, 52.89; H, 7.99; N, 12.34. Found: C, 52.66; H, 7.82; N, 12.55. (CyAP)ZrMe2 (5k). The preparation of complex 5k is identical to that of 5a. Compound 3k (0.500 g, 1.083 mmol) and MeMgBr (2.02 mL, 1.34 M, 2.71 mmol) gave white crystalline 5k (0.395 g, 0.939 mmol, 87 %). 'H NMR 8 6.91 (t, IH, py), 6.51 (t, 2H, py), 4.50 (s, 4H, NC/Y2), 4.45 (buried, 2H, NC/Y), 2.11 (m, 4H, Cy), 1.90 (m, 4H, Cy), 1.60 (m, 10H, Cy), 1.15 (m, 2H, Cy), 0.39 (s, 6H, ZrMe). 13C{'H} NMR 8 165.21, 136.52, 117.15, 57.71, 55.61, 33.31, 31.05, 27.35, 26.66. Anal, calcd. for C21H35N3Zr: C, 59.95; H, 8.38; N, 9.99. Found: C, 59.99; H, 8.46; N, 9.87. (LiAP)ZrMe2 (51). The preparation of complex 51 is identical to that of 5a. Compound 31 (0.700 g, 1.148 mmol) and MeMgBr (1.33 mL, 3.00 M, 3.99 mmol) gave white crystalline 51 (0.468 g, 1.033 mmol, 90 %). 'H NMR 8 6.92 (t, IH, py), 6.50 (d, 2H, py), 4.55 (s, 4H, NC/72), 4.19 (t, 2H, C/Y'Pr2), 2.20 (d of sept, 4H, C/7Me2), 1.21 (d, 12H, CHMe2), 1.16 (d, 12H, CHMe2), 0.57 (s, 6H, ZrMe). I3C{'H} NMR 8 165.16, 136.72, References on page 190 173 129.28, 125.50, 117.06, 65.74, 58.54, 37.68, 32.60, 22.80, 21.91. Anal, calcd. for C23H43N3Zr: C, 61.01; H, 9.57; N, 9.28. Found: C, 60.86; H, 9.48; N, 9.35. (tBAP)ZrMe2 (5m). The preparation of complex 5m is identical to that of 5a. Compound 3m (0.500 g, 1.221 mmol) and MeMgBr (4.10 mL, 1.34 M, 5.49 mmol) gave white crystalline 5m (0.328 g, 0.890 mmol, 73 %). 'H NMR 8 6.88 (t, 1H, py), 6.46 (t, 2H, py), 4.56 (s, 4H, NCH2), 1.66 (s, 18H, CMe3), 0.42 (s, 6H, ZrMe). 13C{'H} NMR 8 165.03, 136.60, 116.83, 59.19, 55.00, 35.33, 29.25. Anal, calcd. for C17H31N3Zr: C, 55.38; H, 8.47; N, 11.40. Found: C, 55.70; H, 8.35; N, 11.34. (BDPP)Zr(CH2Ph)2 (6a). To a diethylether (25 mL) suspension of compound 3a (0.100 g, 0.162 mmol) was added 2.2 equiv of PhCH2MgBr (0.32 mL, 1.13 M, 0.36 mmol) at 23 °C. The suspension was stirred for 12h. The solvent was removed in vacuo. The resulting solid was extracted with toluene (3 x 10 mL) and filtered through Celite to give a bright-yellow solution. The solvent was removed in vacuo, the solid dissolved in a minimum amount of dichloromethane and cooled to -30 °C for 12 h. Yellow crystalline 6a was isolated by filtration and dried under vacuum (0.093 g, 0.128 mmol, 79 %). 'H NMR (d8-toluene, 23 °C) 8 7.30-6.90 (m, Ar and CH2Ph), 6.82 (t, 1H, py), 6.35 (d, 2H, py), 4.82 (br s, 4H, NCff2), 3.85 (br s, 4H, C//Me2), 1.92 (br s, 4H, C#2Ph), 1.45 (br s, 12H, CUMe2), 1.21 (d, 12H, CHMe2). 'H NMR (d8-toluene, -40 °C) 8 7.30-6.90 (m, 6H, Ar and CH2Ph), 6.82 (m, 4H, m -Ph), 6.75 (t, 1H, py), 6.51 (m, 2H, p -Ph), 6.23 (d, 2H, py), 5.90 (d, 4H, o -Ph), 4.81 (AB quartet, 2Jm = 20.2 Hz, 4H, NCtf2), 4.03 (sept, 2H, C//Me2), 3.71 (sept, 2H, C//Me2), 2.10 (s, 2H, Ctf2Ph), 1.64 (s, 2H, C//2Ph), 1.51 (d, 6H, CHMe2), 1.40 (d, 6H, CHMe2), 1.38 (d, 6H, CHMe2),1.08 (d, 6H, CHMe2). Partial "Cf'H} NMR (d8-toluene, 23 °C) 8 68.87 (NC//2). Anal. Calcd for C45H55N3Zr» 1/4 CH2C12 : C, 72.43; H, 7.45; N, 5.60. Found: C, 72.65; H, 7.62; N, 5.59. (BDEP)Zr(CH2Ph)2 (6b). The preparation of compound 6b is identical to that of 6a. Compound 3b (0.300 g, 0.534 mmol) and PhCH2MgBr (1.42 mL, 1.13 M, 1.60 mmol) gave a yellow oily solid 6b. The high solubility of the product made its isolation from the crude oil References on page 190 174 impossible. 'H NMR 8 7.40-6.50 (m, 15H, py, Ar and Ph), 6.35 (d, 4H, Ph), 4.55 (s, 4H, NC//2), 2.89 (q, 8H, C/72Me), 1.61 (s, 4H, ZrC/72Ph), 1.26 (t, 12H, CH2Me). 13C{'H} NMR 8 162.74, 149.81, 141.59, 137.76, 129.59, 126.83, 126.18, 125.79, 122.01, 117.17, 65.69, 60.95, 24.66, 15.15. (BDMP)Zr(CH2Ph)2 (6c). The preparation of compound 6c is identical to that of 6a. Compound 3c (0.075 g, 0.148 mmol) and PhCH2MgBr (0.29 mL, 1.13 M, 0.33 mmol) gave a yellow solid 6c (0.089 g, 0.144 mmol, 97 %). 'H NMR 8 7.08 (m, 4H, Ar), 6.98 (m, 2H, Ar), 6.87 (m, 4H, Ph), 6.84 (t, IH, py), 6.67 (m, 2H, Ph), 6.36 (m, 4H, Ph), 6.34 (d, 2H, py), 4.42 (s, 4H, NCtf2), 2.37 (s, 12H, Me), 1.663 (s, 4H, ZrC//2Ph). 13C{'H} NMR 8 162.85, 150.76, 137.59, 136.25, 129.64, 126.69, 125.40, 121.94, 117.13, 64.12, 60.62, 60.57, 19.62. Anal. Calcd for C37H39N3Zr: C, 72.03; H, 6.37; N, 6.81. Found: C, 71.89; H, 6.65; N, 6.82. (BMPP)Zr(CH2Ph)2 (6g). The preparation of compound 6g is identical to that of 6a. Compound 3g (0.500 g, 0.937 mmol) and PhCH2MgBr (2.63 mL, 0.89 M, 2.34 mmol) gave a yellow solid 6g (0.512 g, 0.794 mmol, 85 %). 'H NMR 8 7.55 (br m, 2H, Ar/Ph), 7.30 (m, 2H, Ar/Ph), 7.15 (m, 4H, Ar/Ph), 6.80 (br s, 6H, Ar/Ph), 6.48 (t, IH, py), 6.48 (br s, 2H, Ar/Ph), 6.29 (d, 2H, py), 5.68 (br s, 2H, Ph), 4.65 (br s, 4H, NC/72), 3.50 (br s, 2H, C#Me2), 2.15 (br s, 4H, C//2Ph), 1.18 (br s, 12H, CHMe2). 13C{'H} NMR 8 162.91, 148.83, 147.10, 137.40, 130.47, 130.07, 126.56, 126.41, 117.07, 67.94, 26.92, 22.51. (BMBP)Zr(CH2Ph)2 (6h). The preparation of compound 6h is identical to that of 6a. Compound 3h (0.500 g, 0.890 mmol) and PhCH2MgBr (2.50 mL, 0.89 M, 2.22 mmol) gave a yellow solid 6h (0.438 g, 0.651 mmol, 73 %). 'H NMR 8 7.50 (m, IH, Ar), 7.42 (m, IH, Ar), 7.18 (m, 4H, Ar and Ph), 7.04 (m, 2H, Ar and Ph), 6.81 (t, 2H, Ar and Ph), 6.73 (t, IH, py), 6.35 (d, 2H, py), 5.71 (m, 2H, Ph), 4.66 (AB quartet, 2JHH = 20.5 Hz, 4H, NC/72), 2.34 (s, 2H, C//2Ph), 1.80 (s, 2H, Ctf2Ph), 1.46 (s, 18H, CMe3). 13C{'H} 8 161.91, 149.65, 148.98, 146.61, 137.36, 137.07, 132.96, 131.10, 130.31, 130.12, 127.36, 126.56, 126.32, 124.95, References on page 190 175 124.14, 119.58, 117.07, 69.41, 65.16, 56.69, 37.17, 33.47. Anal. Calcd. for C41H47N3Zr: C, 73.17; H, 7.04; N, 6.24. Found: C, 73.10; H, 7.15; N, 6.39. (tBAP)Zr(CH2Ph)2 (6m). The preparation of compound 6m is identical to that of 6a. Compound 3m (0.500 g, 1.221 mmol) and PhCH2MgBr (2.75 mL, 0.89 M, 2.45 mmol) gave a yellow solid 6m (0.497 g, 0.954 mmol, 78 %). 'H NMR 5 6.86 (m, 6H, Ph), 6.72 (m, 4H, Ph), 6.60 (t, IH, py), 6.41 (d, 2H, py), 4.24 (s, 4H, NC/72), 2.50 (s, 4H, C//2Ph), 1.48 (s, 18H, CMe3). nCCH) NMR 5 164.37, 148.09, 136.64, 127.81, 127.63, 127.59, 120.43, 116.70, 61.69, 58.58, 55.48, 28.33. Anal, calcd. for C29H39N3Zr: C, 66.87; H, 7.55; N, 8.07. Found: C, 67.05; H, 7.57; N, 7.78. (BDPP)Zr(CH2SiMe3)2 (7a). To a diethylether (25 mL) suspension of compound 3a (0.100 g, 0.178 mmol) was added 2.2 equiv of Me3SiCH2Li (0.037 g, 0.393 mmol) at -20 °C. The suspension was stirred for 12h. The solvent was removed in vacuo. The resulting solid was extracted with toluene (3 x 10 mL) and filtered through Celite to give a bright-yellow solution. The solvent was removed in vacuo, the solid dissolved in a minimum amount of hexanes and cooled to -30 °C for 12 h. Yellow crystalline 7a was isolated by filtration and dried under vacuum (0.109 g, 0.156 mmol, 88 %). 'H NMR 5 7.24 (b, 6H, Ar), 6.86 (t, IH, py), 6.40 (d, 2H, py), 5.0 (brs, 4H, NC/72), 1.52 and 1.28 (br s, 12H each, CHMe2), -0.13 (br s, 18H, SiMeJ. 'H NMR (d8-toluene, T = 70 °C) 6 7.20-7.25 (m, 6H, Ar), 6.98 (t, IH, py), 6.54 (d, 2H, py), 4.96 (s, 4H, NC/Y2), 3.91 (br s, 4H, C//Me2), 1.49 and 1.26 (d, 12H each, CHMe2), 0.65 (s, 4H, ZrC/72Si), -0.18 (s, 18H, SiMe,). 13C{'H} NMR 8 146.13, 127.38, 124.68, 117.32, 67.78, 28.18, 27.46, 24.25, 2.82. Anal. Calcd for C39H63N3Si2Zr: C, 64.94; H, 8.80; N, 5.83. Found: C, 64.94; H, 8.77; N, 5.95. (BDEP)Zr(CH2SiMe3)2 (7b). The preparation of compound 7b is identical to that of 7a. Compound 3b (0.100 g, 0.178 mmol) and Me3SiCH2Li (0.037 g, 0.393 mmol) gave yellow crystalline 7b (0.109 g, 0.156 mmol, 88 %). 'H NMR 5 7.25-7.15 (m, 6H, Ar), 6.88 (t, IH, py), 6.43 (d, 2H, py), 4.77 (s, 4H, NCH2), 3.05 (m, 8H, C//2Me), 1.33 (t, 12H, CH2Me), 0.54 References on page 190 176 (s, 4H, ZrC#2Si), -0.13 (s, 18H, SiMeJ. 13C{'H} NMR 5 163.33, 149.42, 141.39, 138.43, 126.75, 125.84, 117.58, 66.60, 58.79, 24.57, 15.75, 2.99. (BDMP)Zr(CH2SiMe3)2 (7c). The preparation of compound 7c is identical to that of 7a. Compound 3c (0.100 g, 0.198 mmol) and Me3SiCH2Li (0.041 g, 0.435 mmol) gave yellow crystalline 7c (0.103 g, 0.169 mmol, 85 %). 'H NMR 8 7.15 (d, 4H, Ar), 7.03 (m, 2H, Ar), 6.91 (t, 1H, py), 6.47 (d, 2H, py), 4.64 (s, 4H, NCH2), 2.48 (s, 12H, Me), 0.61 (s, 4H, ZrC//2Si),-0.13 (s, 18H, SiMe3). I3C{'H} NMR 8 163.49, 150.53, 138.32, 135.85, 129.34, 125.39, 117.53, 64.94, 58.43, 19.54, 3.00. (BDPP)ZrPh2 (8a). To a diethylether suspension (10 mL) of complex 3a (0.250 g, 0.405 mmol) was added 2.2 equiv of PhMgBr (0.80 mL, 1.12 M, 0.90 mmol) at -30 °C. The solution was stired at roomt temperature for 12 hours. The solvent was removed in vacuo. The solid was extracted with toluene. The solvent was removed under vaccum. The solid dissolved in a minimum amount of a 50:50 toluene:hexanes mixture and the solution was cooled to -30 °C. White crystalline 8a was isolated hy filtration and dried under vaccum (0.197 g, 0.281 mmol, 69 %). 'H NMR 8 7.30-7.10 (m, 12H, Ar and Ph), 7.05 (m, 4H, Ar and Ph), 6.92 (t, 1H, py), 6.45 (d, 2H, py), 4.94 (s, 4H, NCH2), 3.54 (sept, 4H, C//Me2), 1.14 (d, 12H, CHM<?2), 0.91 (d, 12H, CHMe2). 13C{'H} NMR 8 190.41, 163.10, 149.06, 145.97, 138.40, 133.84, 126.71, 125.95, 124.29, 117.61, 68.21, 28.38, 26.41, 23.97. (BMBP)Zr(CH2CMe2Ph)2 (9h). To a diethylether (25 mL) suspension of compound 3h (0.100 g, 0.178 mmol) was added 2.2 equiv of PhCMe2CH2MgCl (0.56 mL, 0.69 M, 0.39 mmol) at -20 °C. The suspension was stirred for 12h. The solvent was removed in vacuo. The resulting solid was extracted with toluene (3 x 10 mL) and filtered through Celite to give a colorless solution. The solvent was removed in vacuo, the solid dissolved in a minimum amount of diethylether and cooled to -30 °C for 12h. White crystalline 9h was isolated by filtration and dried under vacuum (0.107 g, 0.162 mmol, 94 %). 'H NMR 8 7.66 (d, 2H, Ar), 7.55 (d, 2H, Ar), 7.30-6.95 (m, 14H, Ar/Ph), 6.89 (t, 1H, py), 6.43 (d, 2H, py), 4.75 (AB quartet, 2Jm = References on page 190 177 20.8 Hz, 4H, NC/72), 1.61 (s, 2H, C/72CMe2Ph), 1.39 (s, 18H, CMeJ, 1.36 (s, 6H, CH2CMe2Ph), 1.04 (s, 2H, C/Y2CMe2Ph), 1.01 (s, 6H, CH2CM<?2Ph). 13C{'H} NMR 8 162.54, 155.94, 154.22, 150.42, 146.25, 137.90, 132.23, 131.66, 127.45, 127.30, 126.88, 126.04, 125.41, 125.30, 125.03, 124.43, 117.47, 86.50, 82.53, 69.54, 43.81, 40.58, 37.11, 34.51, 33.44, 32.63. (BDPP)Zr(CH2CMe2Ph)CI (10a). To a diethylether (25 mL) suspension of compound 3a (0.100 g, 0.162 mmol) was added 1.2 equiv of PhCMe2CH2MgCl (0.22 mL, 0.88 M, 0.19 mmol) at -20 °C. The suspension was stirred for 12h. The solvent was removed in vacuo. The resulting solid was extracted with toluene (3 x 10 mL) and filtered through Celite to give a colorless solution. The solvent was removed in vacuo, the solid dissolved in a minimum amount of diethylether and cooled to -30 °C for 12h. White crystalline 10a was isolated by filtration and dried under vacuum (0.109 g, 0.152 mmol, 94 %). 'H NMR 8 7.25-7.00 (m, 1 IH, Ar and Ph), 6.86 (t, IH, py), 6.38 (d, 2H, py), 4.76 (AB quartet, 2Jm = 20.9 Hz, 4H, NCtf2), 4.31 and 3.27 (sept, 2H each, C/7Me2), 2.05 (s, 2H, C/Y2CMe2Ph), 1.44, 1.37 and 1.35 (d, 6H each, CHMe2), 1.29 (s, 6H, CH2CMe2Ph), 1.12 (d, 6H, CHMe2). 13C{'H} NMR 8 163.38, 154.39, 148.81, 145.81, 144.84, 138.81, 126.51, 125.26, 125.12, 124.75, 124.58, 117.82, 80.17, 68.06, 44.04, 33.37, 29.14, 27.60, 26.51, 26.41, 25.24, 25.08. Anal. Calcd for C41H54ClN3Zr: C, 68.82; H, 7.61; N, 5.87. Found: C, 69.16; H, 7.72; N, 5.84. (BMBP)Zr(CH2CMe2Ph)Cl (lOh). To a dichloromethane (50 mL) solution of compound 3h (0.500 g, 0.890 mmol) was added 1 equiv of PhCMe2CH2MgCl (1.01 mL, 0.88 M, 0.89 mmol) at -78 °C. The solution was allowed to warm up to room temperature slowly and stirre for 12 hours. The solvent was removed in vacuo. The resulting solid was extracted with toluene (3 x 10 mL) and filtered through Celite to give a colorless solution. The solvent was removed in vacuo, the solid dissolved in a minimum amount of diethylether and cooled to -30 °C for 12h. White crystalline lOh was isolated by filtration and dried under vacuum (0.357 g, 0.541 mmol, 61 %). 'H NMR 8 7.55 (d, 2H, Ar), 7.52 (d, 2H, Ar), 7.25-7.00 (m, 9H, Ar/Ph), 6.93 References on page 190 178 (t, IH, py), 6.47 (d, 2H, py), 4.71 (AB quartet, 2Jm = 20.8 Hz, 4H, NC/Y2), 2.14 (s, 2H, C//2CMe2Ph), 1.46 (s, 18H, CMe3), 1.38 (s, CH2CMe2Ph). 13C{'H} NMR 5 163.09, 153.77, 149.71, 145.88, 138.48, 131.59, 130.90, 129.32, 126.94, 126.35, 125.46, 125.19, 117.76, 82.08, 69.82, 43.70, 37.10, 34.38, 33.59. (BMBP)Zr(Si(SiMe3),)Cl (llh). To an hexanes (15 mL) solution of compound 3h (0.500 g, 0.890 mmol) was added 1 equiv of (Me3Si)3SiLi«3THF (0.460 g, 0.977 mmol) at -78 °C. The solution was allowed to warm up to room temperature slowly and stirre for 12 hours. The solvent was removed in vacuo. The resulting solid was extracted with hexanes (3 x 10 mL) and filtered through Celite to give a colorless solution. The solvent was removed in vacuo to give white solid llh (0.650 g, 0.840 mmol, 94 %). 'H NMR 5 8.12 (d, 2H, Ar), 7.47 (d, 2H, Ar), 7.34 (t, 2H, Ar), 7.16 (t, 2H, Ar), 6.91 (t, IH, py), 6.41 (t, 2H, py), 5.12 (AB quartet, 2Jm = 21.4 Hz, 4H, NC/72), 1.35 (s, 18H, CMe3), 0.45 (s, 27H, SiM<?3). 13C{'H} NMR 5 161.99, 149.10, 143.57, 139.11, 132.79, 131.11, 127.09, 126.81, 117.88, 69.49, 36.87, 33.32, 33.14, 6.16. (BDPP)ZrCpCl (12a). To a diethylether (25 mL) suspension of compound 3a (0.100 g, 0.162 mmol) was added 1.3 equiv of NaCp-DME (0.038 g, 0.213 mmol) at -20 °C. The suspension was stirred for 12h. The solvent was removed in vacuo. The resulting solid was extracted with toluene (3 x 10 mL) and filtered through Celite to give a colorless solution. The solvent was removed in vacuo, the solid dissolved in a minimum amount of diethylether and cooled to -30 °C for 12 h. White crystalline 12a was isolated by filtration and dried under vacuum (0.093 g, 0.144 mmol, 89 %). 'H NMR 5 7.25-7.10 (m, 6H, Ar), 6.75 (t, IH, py), 6.33 (d, 2H, py), 6.04 (s, 5H, Cp), 4.78 (AB quartet, 2Jm = 20.2 Hz, 4H, NC#2), 3.90 and 3.23 (sept, 2H each, C/7Me2), 1.53, 1.35, 1.32 and 0.92 (d, 6H each, CHMe2). 13C{'H} NMR 5 161.50, 157.38, 145.12, 142.52, 137.61, 125.24, 124.77, 123.81, 116.56, 116.26 (Cp), 68.30, 28.70, 27.82, 27.67, 26.68, 24.04, 23.54. Anal. Calcd for C36H46ClN3Zr: C, 66.78; H, 7.16; N, 6.49. Found: C, 66.98; H, 7.24; N, 6.35. References on page 190 179 (BDEP)ZrCpCl (12b). The preparation of compound 12b is identical to that of 12a. Compound 3b (0.100 g, 0.178 mmol) and NaCp'DME (0.040 g, 0.224 mmol) gave white crystalline 12b (0.091 g, 0.154 mmol, 87 %). 'H NMR 5 7.25-7.00 (m, 6H, Ar), 6.79 (t, 1H, py), 6.37 (d, 2H, py), 5.89 (s, 5H, Cp), 4.51 (AB quartet, 2Jm = 20.6 Hz, 4H, NCtf2), 3.05 and 2.49 (m, 4H each, CH2Uc), 1.39 and 1.08 (t, 6H each, CU2Me). i3C{lR} NMR 8 161.48, 159.444, 140.21, 137.62, 137.50, 126.88, 126.11, 124.74, 116.85, 116.38 (Cp), 67.14, 24.59, 24.05, 15.88, 14.84. (BDMP)ZrCpCl (12c). The preparation of compound 12c is identical to that of 12a. Compound 3c (0.100 g, 0.198 mmol) and NaCp'DME (0.045 g, 0.253 mmol) gave white crystalline 12c (0.093 g, 0.174 mmol, 88 %). 'H NMR 8 7.15-6.98 (m, 6H, Ar), 6.83 (t, 1H, py), 6.38 (d, 2H, py), 5.88 (s, 5H, Cp), 4.45 (AB quartet, 2JHH = 20.9 Hz, 4H, NC//2), 2.55 and 1.98 (s, 6H each, Me). 13C{'H} NMR 8 161.75, 159.36, 137.38, 134.89, 132.19, 129.33, 128.76, 124.35, 116.90, 116.43 (Cp), 65.39, 19.00, 18.75. ' (BDPP)Zr(C4H6) (13a). To a diethylether (25 mL) suspension of compound 3a (0.100 g, 0.162 mmol) was added 1.3 equiv of C4H6Mg»2THF (0.044 g, 0.198 mmol) at -20 °C. The suspension was stirred for 12h. The solvent was removed in vacuo. The resulting solid was extracted with toluene (3 x 10 mL) and filtered through Celite to give a bright-yellow solution. The solvent was removed in vacuo, the solid dissolved in a minimum amount of diethylether and cooled to -30 °C for 12 h. Yellow crystalline 13a was isolated by filtration and dried under vacuum (0.093 g, 0.155 mmol, 96 %). 'H NMR 8 7.15-7.00 (m, 2H, Ar), 6.98 (t, 1H, py), 6.57 (d, 1H, py), 6.49 (d, 1H, py), 5.07 (s, 2H, NCH2), 5.03 (m, 2H, ZrCHCtf2), 4.72 (s, 2H, NCH2), 4.00 (sept, 2H, C//Me2), 3.56 (m, 2H, ZrCHC//2), 3.08 (sept, 2H, CtfMe2), 2.38 (sept, 6H each, C#Me2), 1.33, 1.23, 1.16 and 1.01 (d, 6H each, CHM<?2), 0.28 (m, 2H, ZrC//CH2). 13C{'H} NMR 8 165.52, 164.58, 150.75, 149.92, 146.10, 143.78, 137.69, 125.21, 124.89, 124.31, 123.46, 119.35, 117.65, 117.20, 67.99, 67.73, 58.20, 28.48, 27.98, 27.78, 27.48, 24.33, 23.27. References on page 190 180 (BDEP)Zr(C4H6) (13b). The preparation of compound 13b is identical to that of 13a. Compound 3b (0.100 g, 0.178 mmol) and C4H6Mg»2THF (0.044 g, 0.198 mmol) gave yellow crystalline 13b (0.083 g, 0.152 mmol, 85 %). 'H NMR 5 7.15-7.00 (m, 2H, Ar), 6.97 (t, 1H, py), 6.59 (d, 1H, py), 6.51 (d, 1H, py), 4.92 (m, 2H, ZrCHC//2), 4.83 (s, 2H, NCH2), 4.47 (s, 2H, NC//2), 3.41 (m, 2H, ZrCHCtf2), 2.97 (m, 4H, C//2Me), 2.38 (m, 4H, CH2Me), 1.24 and 1.11 (t, 6H each, CH2Me), 0.16 (m, 2H, ZrC//CH2). 13C{'H} NMR 8 165.64, 164.75, 140.95, 138.82, 137.58, 129.35, 126.39, 125.46, 124.72, 124.36, 119.64, 117.79, 117.34, 67.06, 66.57, 58.50, 23.66, 23.36, 15.73, 15.29. (BDMP)Zr(C4H6) (13c). The preparation of compound 13c is identical to that of 13a. Compound 3c (0.100 g, 0.198 mmol) and C4H6Mg»2THF (0.049 g, 0.249 mmol) gave yellow crystalline 13c (0.093 g, 0.190 mmol, 96 %). 'H NMR 8 7.15-6.80 (m, 2H, Ar), 6.91 (t, 1H, py), 6.62 (d, 1H, py), 6.52 (d, 1H, py), 4.98 (m, 2H, ZrCHC//2), 4.47 (s, 2H, NC//2), 4.36 (s, 2H, NCH2), 3.42 (m, 2H, ZrCHC#2), 2.39 and 1.95 (s, 6H each, Me), 0.17 (m, 2H, ZrC//CH2). 13C{'H} NMR 8 165.69, 164.80, 153.40, 151.57, 137.47, 135.49, 133.38, 129.23, 128.24, 124.28, 123.94, 119.59, 117.76, 117.31, 65.31, 64.73, 58.54, 18.36. (BDPP)Zr(C6H6Pr2) (14a). A benzene (10 mL) solution of compound 13a (0.100 g, 0.17 mmol) and an excess of 4-octyne (0.050 g, 0.45 mmol) was heated to 90 °C for 12 hours. The solution changed from yellow to orange. The solvent was removed in vacuo and the resulting solid was recrystalize at -30 °C from a toluene/pentane mixture (10/50). White crystalline 14a was isolated by filtration and dried under vaccum (0.098 g, 0.014 mmol, 84 %). 'H NMR 8 7.25-7.10 (m, 6H, Ar), 7.00 (t, 1H, py), 6.55 (d, 2H, py), 5.35 (m, 1H, ZrCH2C//=CHCH2), 5.01 (AB quartet, 2Jm = 20.6 Hz, 2H NC//2), 4.94 (AB quartet, 2Jm = 20.6 Hz, 2H, NC//2), 4.42 (m, 1H, ZrCH2CH=C#CH2), 4.05 (sept, 1H, C//Me2), 3.66 (m, 3H, C//Me2), 3.12 (d, 2H, ZrCH2CH=CHC//2), 2.45 (dd, 1H, ZrC//2CH=CHCH2), 2.25 (m, 2H, C//2CH2CH3), 2.1 (m, 2H, C//2CH2CH3), 1.60 (m, 1H, ZrC//2CH=CHCH2), 1.60 (m, 2H, CH2C//2CH3), 1.10-1.50 (8 doublets, 3H each, CHMe2), 1.10-1.50 (buried, 2H, CH2Ctf2CH3), 0.88 (t, 3H, References on page 190 181 CH2CH2C//3), 0.60 (t, 3H, CH2CH2C//3). 13C{'H} NMR 8 187.97, 168.97, 163.87, 163.51, 148.38, 147.04, 146.43, 145.84, 145.72, 138.82, 137.91, 129.29, 126.28, 125.45, 124.62, 124.52, 124.38, 123.27, 119.23, 117.38, 117.31, 68.06, 67.66, 67.27, 42.23, 38.91, 34.83, 28.52, 28.44, 28.27, 28.20, 28.07, 27.87, 27.64, 27.35, 24.92, 24.27, 24.07, 23.96, 23.45, 23.25, 15.52, 15.40. (BDPP)Zr(C6H7SiMe,) (15a). The preparation of compound 15a is identical to that of complex 14a. Compound 13a (0.050 g, 0.09 mmol) and trimethylsilylacetylene (0.020 g, 0.20 mmol) gave white crystalline 15a (0.046 g, 0.07 mmol, 79 %). 'H NMR 8 8.02 (t, IH, C(SiMe3)=C//), 7.25-7.10 (m, 6H, Ar), 6.98 (d, IH, py), 6.58 (d, IH, py), 6.55 (d, IH, py), 5.38 (m, IH, ZrCH2C//=CHCH2), 5.03 (AB quartet, 2]m = 20.6 Hz, 2H, NCH2), 4.99 (AB quartet, 2JHH = 20.3 Hz, 2H, NC#2), 4.78 (m, IH, ZrCH2CH=C//CH2), 3.98 (sept, IH, CHMe2), 3.59 (sept, IH, C//Me2), 3.48 (m, 2H, C//Me2), 3.02 (m, 2H, ZrCH2CH=CHC//2), 2.43 (dd, IH, ZrC/72CH=CHCH2), 1.70 (dd, IH, ZrC/72CH=CHCH2), 1.20-1.40 (6 doublets, 18H, CHMe2), 1.09 (d, 3H, CHMe2), 1.07 (d, 3H, CHMe2), -0.03 (s, 9H, SiMe3). 13C{'H} NMR 8 193.83, 172.22, 164.53, 164.04, 147.97, 147.35, 147.06, 146.67, 145.75, 145.55, 141.35, 138.22, 126.52, 125.73, 124.72, 124.58, 124.48, 123.94, 123.34, 117.61, 68.11, 67.52, 67.27, 42.84, 28.74, 28.61, 28.31, 28.25, 28.07, 27.22, 27.09, 23.88, 23.80, 23.21, 22.73, 1.42. (BDPP)Zr(C6H,P-Bu) (16a). The preparation of compound 16a is identical to that of complex 14a. Compound 13a (0.250 g, 0.43 mmol) and 1-hexene (0.100 g, 1.19 mmol) gave white crystalline 16a (0.213 g, 0.31 mmol, 73 %). 'H NMR 8 7.20-7.05 (m, 6H, Ar), 6.87 (t, IH, py), 6.45 (d, IH, py), 6.44 (d, IH, py), 5.41 (m, IH, ZrCH2C//=CHCH2), 4.80 (AB quartet, 2Jm = 19.8 Hz, 2H, NCtf2), 4.69 (AB quartet, 2JHH = 19.8 Hz, 2H, NC//2), 3.80 (m, 3H, C//Me2), 3.80 (m, IH, ZrCH2CH=C//CH2), 3.38 (sept, IH, C//Me2), 3.17 (m, IH, ZrCH2C//Bu), 2.93 (br d, IH, ZrCH2CH=CHC/72), 2.51 (dd, IH, ZrC//2CH=CHCH2) 2.17 (m, IH, ZrCH2CH=CHC/72), 1.72 (m, IH, ZrC/Y2CHBu), 1.46 (m, IH, ZrC//2CH=CHCH2), References on page 190 182 1.28-1.43 (5 doublets, 15H, CHMe2), 1.28-1.43 (buried, 6H, CH2CH2CH2), 1.22 (d, 3H, CHMe2), 1.08 (d, 3H, CHMe2), 1.05 (d, 3H, CUMe2), 0.92 (t, 3H, CH2C//3), 0.12 (t, 1H, ZrC//2CHBu). 13C{'H} NMR 8 163.03, 162.82, 149.55, 148.22, 146.27, 145.90, 145.51, 137.76, 135.93, 125.79, 125.08, 124.45, 124.23, 123.86, 123.63, 120.48, 117.18, 67.19, 67.01, 66.51, 56.95, 54.10, 42.49, 41.37, 31.11, 29.50, 29.39, 28.03, 27.67, 27.54, 27.46, 26.96, 26.53, 24.80, 24.47, 24.04, 23.47, 14.51. Anal. Calcd for C41H59N3Zr: C, 71.87; H, 8.68; N, 6.13. Found: C, 72.00; H, 8.80; N, 6.12. (BDPP)ZrPr2 (17a). To an hexanes (15 mL) suspension of complex 3a (0.500 g, 0.809 mmol) was added 2.5 equiv of PrMgCl (1.01 mL, 2.00 M, 2.02 mmol) at -30 °C. The reaction was stired at room temperature for 12 hours. The solvent was removed under vaccum and the solid extracted with hexanes. The volume of the solution was reduce to 5 mL. The solution was cooled to -30 °C for 12 hours. White crystalline 17a was isolated by filtration and dried under vaccum (0.369 g, 0.445 mmol, 55 %). 'H NMR 5 7.25-7.10 (m, 6H, Ar), 6.87 (t, 1H, py), 6.41 (d, 2H, py), 4.95 (s, 4H, NC//2), 3.90 (sept, 4H, CHMeJ, 1.46 (d, 12H, CHMe2), 1.40 (m, 8H, C//2C//2Me), 1.28 (d, 12H, CUMe2), 0.82 (t, 6H, CH2CH2Me). 13C{'H} NMR 5 163.09, 148.17, 146.50, 138.05, 129.29, 125.87, 124.19, 117.40, 67.43, 64.02, 28.13, 27.82, 27.43, 24.57, 20.26, 19.86. Anal. Calcd for C37H55N3Zr: C, 70.20; H, 8.76; N, 6.64. Found: C, 70.46; H, 8.55; N, 6.47. (BDPP)ZrBu2 (18a). The preparation of complex 18a is identical to that of 17a. Complex 3a (0.500 g, 0.809 mmol) and BuMgCl (1.01 mL, 2.00 M, 2.02 mmol) gave white crystalline 18a (0.434 g, 0.656 mmol, 81 %). 'H NMR 8 7.25-7.10 (m, 6H, Ar), 6.82(t, 1H, py), 6.36 (d, 2H, py), 4.90 (s, 4H, NCH2), 3.83 (sept, 4H, C//Me2), 1.40 (d, 12H, CHMe2), 1.36 (buried, 4H, Bu), 1.22 (d, 12H, CHMe2), 1.09 (m, 4H, Bu), 0.81 (m, 4H, Bu), 0.70 (t, 6H, Bu). I3C{'H} NMR 8 163.11, 148.29, 146.52, 138.11, 125.83, 124.20, 117.44, 67.42, 60.38, 28.61, 28.15, 27.48, 24.60, 14.14. References on page 190 183 (iPAP)ZrEt2 (19j). The preparation of complex 19j is identical to that of 17a. Complex 3j (0.500 g, 1.670 mmol) and EtMgCl (1.69 mL, 2.00 M, 3.38 mmol) gave white crystalline 19j (0.418 g, 1.134 mmol, 68 %). !H NMR 5 6.92 (t, IH, py), 6.54 (d, 2H, py), 4.94 (sept, 2H, NC/7Me2), 4.47 (s, 4H, NC//2), 1.61 (t, 4H, C/Y2Me), 1.40 (d, 12H, NCHMe2), 0.82 (q, 6H, CH2Me). 13C{'H} NMR 8 165.11, 136.57, 117.28, 55.90, 46.89, 44.59, 22.26, 12.13. (iPAP)ZrCl(Pr) (20j). To a dichloromethane solution of complex 3j (1.000 g, 2.622 mmol) was added 1 equiv of 'PrMgCl (1.31 mL, 2.00 M, 2.62 mmol) at -78 °C. The solution was allowed to warm up to room temperature and stired for 12 hours. The solvent was removed in vacuo . The resulting brown solid was extracted with toluene (3x15 mL) and filtered through Celite. The solvent was removed in vacuo. The solid was dissolved in a minimum ammount of diethylether and cooled to -30 °C for 12 hours. White crystalline 20j was isolated by filtration and dried under vaccum (0.813 g, 1.670 mmol, 64 %). 'H NMR 8 6.93 (t, IH, py), 6.48 (d, 2H, py), 5.07 (sept, 2H, NC/YMe2), 4.32 (AB quartet, 2JHH = 20.4 Hz, 4H, NC//2), 1.44(m, 6H, CHMe2), 1.44 (m, IH, C/YMe2), 1.35 (d, 6H, NCHMe2), 1.27 (d, 6H, NCHMe2). l3C{'H} NMR 8 165.01, 136.89, 117.40, 55.97, 55.64, 47.41, 21.83, 21.74, 21.29. Anal. Calcd for C16H28N3ZrCl: C, 49.39; H, 7.25; N, 10.80. Found: C, 48.99; H, 7.35; N, 10.74. (BDPP')ZrPr (21a). A benzene solution (15 mL) of complex 17a (0.500 g, 0.790 mmol) was heated to 65 °C for 12 hours. The solvent was removed in vacuo. The resulting tight yellow solid was extracted with pentane (3 x 50 mL) and filtered through Celite. The solvent was removed in vacuo. The solid was dissolved in a minium ammount of a 50:50 hexanes:diethylether solution and cooled to -30 °C for 24 hours. White crystalline 21a was isolated by filtration and dried under vaccum (0.352 g, 0.598 mmol, 76 %). 'H NMR 8 7.45-7.15 (m, 6H, Ar), 7.00 (t, IH, py), 6.52 (d, 2H, py), 4.92 (AB quartet, 2Jm = 20.5 Hz, 2H, NC//2), 4.90 (AB quartet, 2]m = 20.6 Hz, 2H, NC/72), 4.15 (sept, IH, C/7Me2), 3.62 (sept, IH, C//Me2), 3.43 (br m, IH, C/Y(Me)CH2), 3.34 (sept, IH, C/7Me2), 1.47 (d, 3H, CHMe2), 1.35-1.45 (m, 11H, CHMe2 References on page 190 184 and CH(Me)CH2), 1.30 (d, 3H, CHMe2\ 1.20 (d, 3H, CHMe2), 1.17 (d, 3H, CHMe2), 0.89 (m, 2H, CH2 Pr), 0.68 (t, 3H, CH2CU2Me), 0.44 (m, 2H, CH2 Pr). 13C{'H} NMR 8 165.40, 164.15, 148.97, 148.08, 147.08, 146.12, 145.28, 138.01, 126.11, 125.84, 124.54, 124.17, 123.05, 117.77, 117.41, 67.70, 65.23, 63.88, 59.87, 37.90, 28.05, 27.88, 26.60, 26.42, 25.07, 24.30, 23.96, 20.03, 18.21. Anal. Calcd for C34H47N3Zr: C, 69.34; H, 8.04; N, 7.13. Found: C, 69.52; H, 8.19; N, 6.99. (BDPP')ZrBu (22a). The preparation of complex 22a is identical to that of 21a. Compound 18a (0.500 g, 0.756 mmol) gave white crystalline 22a (0.328 g, 0.544 mmol, 72 %). 'H NMR 8 7.45-7.15 (m, 6H, Ar), 6.92 (t, 1H, py), 6.47 (d, 2H, py), 4.91 (AB quartet, 2JHH = 20.7 Hz, 2H, NCH2), 4.89 (AB quartet, 2Jm = 20.6 Hz, 2H, NCH2), 4.17 (sept, 1H, C//Me2), 3.63 (sept, 1H, C//Me2), 3.41 (br m, 1H, C//(Me)CH2), 3.33 (sept, 1H, C//Me2), 1.50 (d, 3H, CHMe2), 1.43 (d, 3H, CUMe2), 1.41 (d, 3H, CHMe2), 1.39 (d, 3H, CHMe2), 1.32 (d, 3H, CHMe2), 1.21 (d, 3H, CHMe2), 1.16 (d, 3H, CUMe2), 1.00 (m, 2H, CH(Me)C//2), 1.00 (m, 2H, CH2 Bu), 0.66 (m, 2H, CH2 Bu), 0.66 (t, 3H, CH2CH2CH2Me), 0.38 (m, 2H, CH2 Bu). 13C{'H} 8 165.50, 164.21, 149.13, 148.07, 147.06, 146.31, 145.27, 137.91, 126.06, 125.85, 124.52, 124.15, 123.03, 117.74, 117.37, 67.69, 65.22, 62.92, 56.14, 38.00, 28.34, 28.05, 27.92, 27.88, 27.81, 26.62, 26.54, 26.43, 25.00, 24.26, 23.91, 14.32. [(BDPP)Zr(CH2Ph)]+[PhCH2B(C6Fs)3] (23a). A C6D6 solution of complex 6a (0.050 g, 0.069 mmol) was added to solid B(C6F5)3 (0.035 g, 0.068 mmol) at 23 °C. The solution was allowed to react for 30 minutes. 'H NMR 8 7.20-6.90 (m, 6H, ph), 6.75 (t, 2H, meta ZrCH2P/i), 6.70 (t, 1H, py), 6.25 (d, 2H, ortho BCH2P/i), 6.58 (t, 1H, para ZrCH2P/i), 6.38 (d, 2H, ortho ZrCU2Ph), 6.27 (t, 1H, para BCH2P/i), 6.13 (d, 2H, py), 6.04 (t, 2H, meta BCH2Ph), 4.33 (AB quartet, 4H, NC//2), 3.57 (br m, 2H, BC//2Ph), 3.20 (sept, 2H, C//Me2), 2.59 (sept, 2H, C#Me2), 2.40 (s, 2H, ZrC//2Ph), 1.43 (d, 6H, CUMe2), 1.14 (d, 6H, CUMe2), 1.04 (d, 6H, CHMe2), 0.61 (d, 6H, CHMe2). References on page 190 185 (BDPP)Zr(HN*-Bu)Me (24a). An hexane solution of ?-BuNH2 (1.73 mL, 1.00 M, 1.73 mmol) was added to an hexanes suspension (10 mL) of complex 5a (1.000 g, 1.733 mmol). The reaction mixture was stired at room temperature for 12 hours. The solution was filtered to remove any insoluble impurities. The solvent was removed under vaccum to afford white crystalline 24a (0.987 g, 1.557 mmol, 90 %). 'H NMR 8 7.25-7.10 (m, 6H, Ar), 6.85 (t, IH, py), 6.42 (d, 2H, py), 4.92 (AB quartet, 'J^ = 20.4 Hz, 4H, NCH2), 4.21 (sept, 2H, CHMe2), 3.98 (br s, 2H, NH), 3.48 (sept, 2H, CHMe2), 1.57 (d, 6H, CHMe2), 1.42 (d, 6H, CHMe2), 1.37 (d, 6H, CHMe2), 1.13 (d, 6H, CHMe2), 0.77 (s, 9H, CMe,), 0.63 (s, 3H, ZrMe). l3C{lU} NMR 8 163.02, 150.26, 146.93, 144.78, 125.45, 124.24, 124.20, 117.37, 66.92, 54.45, 28.50, 27.70, 27.37, 26.91, 24.70, 24.60, 14.60. Anal. Calcd for C36H54N4Zr • C6H14: C, 70.04; H, 9.52; N, 7.78. Found: C, 69.73; H, 9.04; N, 7.63. (BDPP')Zr(HNf-Bu) (25a). A benzene solution (25 mL) of complex 24a (0.500 g, 0.789 mmol) was heated to 80 "C in a glass bomb for 12 hours. The solvent was removed in vacuo. The resulting white solid was dissolved in a minimum ammount of pentane and cooled to -30 °C for 24 hours. White crystalline 25a was isolated by filtration and dried under vaccum (0.315 g, 0.510 mmol, 65 %) (quantitative by 'H NMR spectrsocopy). 'H NMR 8 7.40-7.10 (m, 6H, Ar), 6.92 (t, IH, py), 6.47 (d, IH, py), 6.43 (d, IH, py), 4.92 (AB quartet, 2Jra = 20.5 Hz, 2H, NCH2), 4.79 (AB quartet, 2JHH = 20.5 Hz, 2H, NCH2), 4.15 (sept, IH, C/7Me2), 4.02 (s, IH, NH), 3.57 (sept, IH, C//Me2), 3.42 (m, IH, C/7(Me)CH2), 3.17 (sept, IH, C/7Me2), 1.52 (d, 3H, CHMe2), 1.47 (d, 3H, CHMe2), 1.40 (buried, 2H, CH(Me)C/72), 1.37 (d, 3H, CHMe2), 1.34 (d, 3H, CHMe2), 1.26 (d, 3H, CHMe2), 1.24 (d, 3H, CHMe2), 1.16 (d, 3H, CHMe2), 0.81 (s, 9H, N'Bu). 13C{'H} NMR 8 165.89, 163.82, 149.73, 148.83, 147.61, 146.83, 146.41, 144.56, 137.81, 125.60, 124.79, 124.33, 124.06, 12.56, 117.52, 117.23, 67.96, 65.40, 57.55, 54.21, 38.18, 33.99, 27.95, 27.86, 27.57, 27.09, 26.87, 26.75, 26.57, 25.02, 24.75, 24.42, 24.12. Anal. Calcd for C36H54N4Zr • C5H12: C, 69.61; H, 9.05; N, 8.12. Found: C, 69.39; H, 8.89; N, 7.66. References on page 190 186 Molecular Orbital Calculations. All molecular orbital calculations were performed on a CAChe Worksystem, a product developed by Tektronix. The parameters used for the Extended Hiickel calculations of the pyridine diamide model (restricted to C2v symmetry) were taken from the literature x43and are listed in the Appendix. The bond lengths and angles were taken from the X-ray crystal structure analysis of (BDEP)ZrMe2 (5b) (vide infra). The Cartesian coordinates, a full list of the eigenvalues and symmetry labels for the model can be found in the Appendix. Ethylene polymerization. The solvents (heptane, toluene) and 1-hexene were freshly distilled from Na/K before use. In a glovebox, a 500 mL stirred reactor was charged with the desired amounts of solvent, cocatalyst and comonomer. The metal complex was suspended in heptane (0.5 mL). The suspension was then transferred to a catalyst addition device and the reactor sealed. The reactor was purged with ethylene and heated to 60 °C. The catalyst was injected and the reactor pressurized to 100 psi with ethylene. The polymerization was allowed to proceed for the desired time and the solution was quenched with 15 mL of a 1.0 M HCl/MeOH solution. The polymer was filtered off, washed with water and acetone, and dried to constant weight at 100 °C. X-ray Crystallographic Analysis of complex 5b. A suitable crystal of 5b was grown from a saturated ether solution at -30 °C. Crystal data may be found in the appendix. Data were collected on a Siemens P4 diffractometer with the XSCANS software package 144. The Laue symmetry 2/m was determined by merging symmetry equivalent positions. A total of 5706 data were collected in the range of 9 = 1.77-25.0° (-l<h<14, -l<k<18, -18<1<17). Three standard reflections monitored at the end of every 297 reflection collected showed no decay of the crystal. The data processing, solution and refinement were done using SHELXTL-PC programs!45_ The faces of the crystal were indexed and the distance between them measured for a Gaussian absorption correction on the data. During the least-squares cycles, the isotropic temperature factor for methyl groups C(19) and C(29) were relatively high, 0.15 and 0.13, References on page 190 187 respectively. Attempts to model the disorder did not yield satisfactory results. Anisotropic thermal parameters were refined for all non-hydrogen atoms except the carbons in the two phenyl rings. The phenyl and pyridine were restrained to have two-fold symmetry. The C-Me distances were restrained to be equal using the option SADI. Some hydrogen atoms were observed in the least-squares cycles, however, no attempt was made to locate them. All hydrogen atoms were placed in calculated positions. In the final difference Fourier synthesis the electron density fluctuates in the range 0.891 to -0.421 e A3. X-ray Crystallographic Analysis of complex 5k. Unit-cell parameters were calculated from reflections obtained from 60 data frames collected at different secdons of the Ewald sphere. The systematic absences in the diffraction data and the determined unit-cell parameters were uniquely consistent for the reported space group. Semi-empirical absorption correction, based on redundant data at varying effective azimuthal angles, was applied to the data. All non-hydrogen atoms were refined with anisotropic displacement coefficients. All hydrogen atoms were treated as idealized contributions. The structure was solved by direct methods, completed by subsequent Fourier syntheses and refined with full-matrix least-squares methods. All scattering factors and anomalous dispersion coefficients are contained in the SHELCTL 5.03 program library146 X-ray Crystallographic Analysis of complex 6a. Air-sensitive, yellow needle like crystals were grown from a mixture of dichloromethane an cyclohexane. A preliminary examination of several crystals indicated that they were poorly diffracting and twinned. A cut-crystal with the dimension 0.35 x 0.30 x 0.15 mm, mounted inside a Lindemann capillary tube and flame sealed, was found suitable and used for the data collection. The X-ray diffraction experiments were carried out on a Siemens P4 diffractometer with XSCANS software package*44 using graphite monobromated Mo Koc radiation at 25 °C. The cell constants were obtained by centering 21 reflections (9.2 < 20 < 24.9°). The Laue symmetry 2/m was determined References on page 190 188 by merging symmetry equivalent reflections. A total of 3654 data ware collected in the 8 range 1.880 - 21.0 ° (-12<h<0, 0<k<20, -13<1<14) in u scab mode at variable scan speed (2-30 deg.min). Background measurements were made at the ends of the scan range each for 0.5% of total scan time. Three standard reflections monitored at the end of every 297 reflection collection indicated that the crystal was decaying. At the end of 28 = 42°, the crystal decay was 26.3 % and therefore data collection was stopped. The data processing, solution and refinements were done using SHELXTL PC programs145. No absorption was applied to the data (u. = 0.311 mm'1). Due to low data-to-parameter ration (6.3:1), only Zr(l) was refined anisotropically. Individual isotropic thermal parameters were refined for the rest of the non-hydrogen atoms. The four phenyl groups were treated as regular hexagons and ideal geometry was imposed on all the 2-propyl groups using DFIX (C-C = 1.542 A and C...C = 1.633 x d(C-Q). No attempt was made to locate the hydrogen atoms. However all the hydrogen atoms were placed in the calculated position. In the final least-squares refinement cycle on F, the model converged to R= 0.0972, wR = 0.1077 and Goof = 1.62 for 989 observations with Fo>4a (Fo) and 156 parameters. In the final difference Fourier synthesis the electron density fluctuates in the range 0.46 to -0.48 e A3. There were no shifts in the final cycles. X-ray Crystallographic Analysis of complex 13a. Unit-cell parameters were calculated from reflections obtained from 60 data frames collected at different sections of the Ewald sphere. The systematic absences in the diffraction data and the determined unit-cell parameters are consistent for space groups I42d and F^md. Although both space groups were explored, only the solution in I42d yielded chemically reasonable and computationally stable results. No absorption corrections were required (u = 3.36 cm"1). The compound molecule is located on a two-fold axis with the conjugated diene disordered with a 50/50 site occupation distribution. The diene ligand was refined as a flat, rigid body with chemically equivalent bonds restrained to be equal. A cocrystallized, partially occupied, ether solvent molecule was located severely disordered at a four-fold rotoinversion axis with a net References on page 190 189 compound to solvent occupancy ratio of 1:0.35. The flack parameter refined to 0.0(2) indicating that the true hand of the data was correcdy determined. The distorted conjugated diene and solvent molecule were refined isotropically without hydrogen atoms. All non-hydrogen undistorted atoms were refined with anisotropic displacement coefficients. All hydrogen groups were treated as idealized contributions except those on the disordered groups which were ignored. The largest remaining features in the final electron density map are located 0.8 A near the zirconium atom and were considered as artifacts arising from less than ideal absorption corrections. The structure was solved by direct methods, completed by subsequent Fourier syntheses and refined with full-matrix least-squares methods. All scattering factors and anomalous dispersion coefficients are contained in the SHELXTL5.03 program library146. References on page 190 190 5 References (1) Bradley, D. C; Thomas, I. M. Chemical Society London. Proceedings 1959, 225. (2) Bradley, D. C; Thomas, I. M. J. Chem. Soc. 1960, 3857. (3) Bradley, D. C; Gitlitz, M. H. J. Chem. Soc. (A) 1969, 980. (4) Gibbins, S. G.; Lappert, M. F.; Pedley, J. B.; Sharp, G. J. J. Chem. Soc, Dalton Trans. 1975, 72. (5) Airoldi, G.; Bradley, D. C. Inorg. Nucl. Chem. Letters 1975, ii, 155. (6) Chandra, G.; Lappert, M. F. J. Chem. Soc. (A) 1968, 1940. (7) Chandra, G.; George, T. A.; Lappert, M. F. J. Chem. Soc, Chem, Commun. 1967, 687. (8) Airoldi, C; Bradley, D. C; Chudzynska, H.; Hursthouse, M. B.; Malik, K. M. A.; Raithby, P. R. J. Chem, Soc, Dalton Trans. 1980, 2010. (9) Andersen, R. A. Inorg. Chem. 1979,18, 1724. (10) Burger, H.; Wiegel, K. Z. Anorg. Allg. Chem, 1976, 426, 301. (11) Burger, H.; Schlingmann, M.; Pawelke, V. Z. Anorg. Chem. 1976,419, 116, 121. (12) Ziegler, K.; Holzkamp, E.; Breil, H.; Martin, H. Angew. Chem, 1955, 67, 541. (13) Ziegler, K. Angew. Chem, 1964, 76, 545. (14) Natta, G.; Corradini, P. Atti Accad. naz. Lincei Mem, CI. Sci. Fis. Mat. Nat. Sez. II 1955, 5, 73. (15) Natta, G. Angew. Chem. 1956, 68, 393. (16) Natta, G. Angew. Chem. 1964, 76, 553. (17) Natta, G.; Pino, P.; Massanti, G.; Giannini, U. J. Am. Chem. Soc. 1957, 79, 2975. (18) Natta, G.; Pino, P.; Mazzanti, G.; Giannini, U.; Mantica, E.; Peraldo, M. Chim. Ind. (Paris) 1957, 39, 19. (19) Breslow, D. S.; Newburg, N. R. J. Am. Chem. Soc. 1957, 79, 5072. (20) Breslow, D. S. US Pat. Appl. 537039; Breslow, D. S., Ed., 1955. (21) Jordan, R. F. Advances in Organometallic Chemistry 1991, 32, 325. References on page 190 191 (22) Jordan, R. F. J. Chem. Educ. 1988, 65, 285. (23) Jordan, R. F.; Dasher, W. E.; Echols, S. F. J. Am. Chem. Soc. 1986,108, 1718. (24) Jordan, R. F.; Bajgur, C. S.; Willet, R.; Scott, B. J. Am. Chem. Soc. 1986, 707, 7410. (25) Jordan, R. F.; Lapointe, R. E.; Bajgur, C. S.; Echols, S. F.; Willet, R. J. Am. Chem, Soc. 1987,109, 4111. (26) Jordan, R. F.; Bajgur, C. S.; Dasher, W. E.; Rheingold, A. L. Organometallics 1987, 6, 1041. (27) Jordan, R. F.; Lapointe, R. E.; Bradley, P. K.; Baenziger, N. Organometallics 1989, 8, 2892. (28) Jordan, R. F.; Bradley, P. K.; Lapointe, R. E.; Taylor, D. F. New J. Chem. 1990, 14, 505. (29) Jordan, R. F.; Bradley, P. K.; Baensiger, N. C; Lapointe, R. E. J. Am. Chem. Soc. 1990, 112, 1289. (30) Jordan, R. F.; Lapointe, R. E.; Baenziger, N.; Hinch, G. D. Organometallics 1990, 9, 1539. (31) Crowther, D. J.; Borkowsky, S. L.; Swenson, D.; Meyer, T. Y.; Jordan, R. F. Organometallics 1993,12, 2897. (32) Bochmann, M.; Wilson, L. M.; Hursthouse, M. B.; Short, R. L. J. Chem. Soc, Chem. Commun. 1986, 1610. (33) Bochmann, M.; Wilson, L. M.; Hursthouse, M. B.; Short, R. L. Organometallics 1987, 6, 2556. (34) Bochmann, M.; Wilson, L. M.; Hursthouse, M. B.; Motevalli, M. Organometallics 1988, 7, 1148. (35) Bochmann, M.; Jaggar, A. J.; Nicholls, J. C. Angew. Chem. 1990, 102, 830. (36) Bochmann, M.; Jaggar, A. J.; Nicholls, J. C. Angew. Chem., Int. Ed. Engl. 1990, 29, 780. References on page 190 192 (37) Bochmann, M.; Jaggar, A. J. J. Organomet. Chem, 1992, 424, C5. (38) Bochmann, M.; Lancaster, S. J. J. Organomet. Chem. 1992, 434, CL (39) Eshuis, J. J. W.; Tan, Y. Y.; Teuben, J. H. J. Mol. Catal. 1990, 62, 277. (40) Eshuis, J. J. W.; Tan, Y. Y.; Meetsma, A.; Teuben, J. H.; Renkema, J.; Evens, G. G. Organometallics 1992,11, 362. (41) Taube, R.; Krukowka, L. J. Organomet. Chem. 1988, 347, C9. (42) Hlatky, G. G.; Turner, H. W.; eckman, R. R. J. Am. Chem. Soc. 1989, 111, 2728. (43) Hlatky, G. G.; eckman, R. R.; Turner, H. W. Organometallics 1992,11, 1413. (44) Patat, F.; Sinn, H. Angew. Chem. 1958, 70, 496. (45) Collins, S.; Kuntz, B. A.; Taylor, N. J.; Ward, D. G. J. Organomet. Chem. 1988, 342, 21. (46) Ewen, J. A. J. Am, Chem, Soc. 1984, 106, 6355. (47) Wild, F. R. W. P.; Zsolnai, L.; Huttner, G.; Brintzinger, H. H. J. Organomet. Chem. 1982,232,233. (48) Wild, F. R. W. P.; Wasiucionek, M.; Huttner, G.; Brintzinger, H. H. J. Organomet. Chem. 1985, 288, 63. (49) Waymouth, R. M.; Bangerter, F.; Pino, P. Inorg. Chem, 1988, 27, 758. (50) Collins, S.; Gauthier, W. J.; Holden, D. A.; kuntz, B. A.; Taylor, N. J.; Ward, D. G. Organometallics 1991,10, 2061. (51) Grossman, R. B.; Doyle, R. A.; Buchwald, S. L. Organometallics 1991,10, 1501. (52) Piemontesi, F.; Camurati, I.; Resconi, L.; Balboni, D.; Sironi, A.; Moret, M.; Zeigle, R.; Piccolrovazzi, N. Organometallics 1995,14, 1256. (53) Diamond, G. M.; Rodewald, S.; Jordan, R. F. Organometallics 1995,14, 5. (54) Bochmann, A.; Lancaster, S. J. Angew. Chem., Int. Ed. Engl. 1994, 33, 1634. (55) Mengele, W.; Diebold, J.; Troll, C; Roll, W.; Brintzinger, H.-H. Organometallics 1993, 12, 1931-1935. References on page 190 193 (56) Brintzinger, H. H.; Fischer, D.; Miilhaupt, R.; Rieger, B.; Waymouth, R. M. Angew. Chem., Int. Ed. Engl. 1995,34, 1143. (57) Kaminsky, W.; Kiilper, K.; Brintzinger, H. H.; Wild, F. R. W. P. Angew. Chem. 1985, 95, 507. (58) Kaminsky, W.; Kulper, K.; Brintzinger, H. H.; Wild, F. R. W. P. Angew. Chem., Int. Ed. Engl. 1985, 24, 507. (59) Razavi, A.; Atwood, J. L. J. Am. Chem. Soc. 1993, 775, 7529. (60) Razavi, A.; Thewalt, U. J. Organomet. Chem. 1993, 445, 111. (61) Razavi, A.; Ferrara, J.jomv 1992, 435, 299. (62) Waymouth, R. M.; Coates, G. R. Science 1995, 267, 222. (63) Ewen, J. A.; Elder, M. J.; jones, R. L.; Haspeslagh, L.; Atwood, J. L.; Bott, S. G.; Robinson, K. Makromol. Chem. Macromol. Symp. 1991, 48/49, 253. (64) Ewen, J. A.; Elder, M. J.; Jones, R. L.; Curtis, S.; CHeng, H. N. Stud. Surf. Sci. Catal. 1990, 56, 439. (65) Ewen, J. A.; Jones, R. L.; Razavi, A. J. Am. Chem. Soc. 1988, 110, 6255. (66) Mislow, K.; Raban, M. Stereoisomeric Relationships of Groups in Molecultes; Mislow, K.; Raban, M., Ed., 1967, pp 1-38. (67) Ewen, J. A.; Elder, M. J.; Jones, R. L.; Haspeslagh, L.; Atwood, J. L.; Bott, S. G.; Robinson, K. Makromol. Chem, Macromol. Symp. 1991, 48/49, 253. (68) Ewen, J. A.; Elder, M. J. Eur. Pat, Apppl. EP-A - 537130; Ewen, J. A.; Elder, M. J., Ed., 1993. (69) Zambelli, A.; Grassi, A.; Galimberti, M.; Mazzocchi, R.; Piemontesi, F. Makromol. Chem. Rapid. Commun. 1991, 72, 253. (70) Busico, V.; Mevo, L.; Palumbo, G.; Zambelli, A. Makromol. Chem. 1983, 184, 2193. (71) Canich, J. A. ; Canich, J. A., Ed., European Patent Application EP-420-436-A1; Vol. April 4, 1991. References on page 190 194 (72) Canich, J. A.; Turner, H. W. ; Canich, J. A.; Turner, H. W., Ed., W. PCT Int. Appl. WO 92/12162; Vol. filing date December 26, 1991. (73) Stevens, J. C; Timmers, F. J.; Wilson, D. R.; Schmidt, G. F.; Nickias, P. N.; Rosen, R. K.; Knight, G. W.; Lai, S. Y. Constrained Geometry Addition Polymerization Catalysts; Stevens, J. C; Timmers, F. J.; Wilson, D. R.; Schmidt, G. F.; Nickias, P. N.; Rosen, R. K.; Knight, G. W.; Lai, S. Y., Ed.; (Dow) European Patent Applicadon EP-416-815-A2, March 13,1991. (74) Shapiro, P. J.; Bunel, E.; Schaefer, W. P.; Bercaw, J. E. Organometallics 1990, 9, 867. (75) Okuda, J.; Schattenmann, F. J.; Wocadlo, S.; Massa, W. Organometallics 1995, 14, 789. (76) van der Linden, A.; Schaverien, C. J.; Meijboom, N; Ganter, C; Orpen, A. G. J. Am. Chem. Soc. 1995, 117, 3008. (77) Haeg, M. E.; Whitlock, B. J.; Whitlock Jr., H. W. J. Am. Chem, Soc. 1989, 111, 692. (78) Calculations were performed using CAChe Scientific software by Tektronix. (79) Mu, Y.; Piers, W. E.; MacGillivray, L. R.; Zaworotko, M. J. Polyhedron 1995,14, 1. (80) Andersen, R. A. Inorganic Chemistry 1979, 18, 2928. (81) Warren, T. FL; Schrock, R. R.; Davis, W. M. Organometallics 1996,15, 562. (82) Anderson, H. H. J. Am, Chem. Soc. 1953, 75, 1576. (83) Cummins, C. C; Baxter, S. M.; Wolczanski, P. T. J. Am. Chem. Soc. 1988,110, 8731. (84) Hughes, A. K.; Meetsma, A.; Teuben, J. A. Organometallics 1993,12, 1936. (85) Alcock, N. M.; Pierce-Butler, M.; Willey, G. R. J. Chem. Soc, Chem. Commun. 1974, 627. (86) Bai, Y.; Roesky, H. W.; Noltemeyer, M.; Witt, M. Chem. Ber. 1992,125, 825. (87) Cummins, C. C; Duyne, G. D. V.; Schaller, C. P.; Wolczanski, P. T. Organometallics 1991, 10, 164. (88) Planalp, R. P.; Andersen, R. A.; Zalkin, A. Organometallics 1983, 2, 16. References on page 190 195 (89) Hunter, W. E.; Hrncir, D. C; Bynum, V.; Penttila, R. A.; Atwood, J. L. Organometallics 1983, 2, 750. (90) Lauher, J. W.; Hoffmann, R. J. Am. Chem. Soc. 1976, 98, 1729. (91) Nugent, W. A.; Haymore, B. L. Coord. Chem, Rev. 1980, 31, 123. (92) Cummins, C. C; Baxter, S. M.; Wolczanski, P. T. J.Am. Chem. Soc. 1988,110, 8733. (93) Rocklage, S. M.; Schrock, R. R.; Churchill, M. R.; Wasserman, J. H. Organometallics 1982, 7, 1332. (94) Edwards, D. S.; Schrock, R. R. J. Am, Chem. Soc. 1982, 104, 6806. (95) Scholz, J. Chem. Ber. 1987,120, 1369. (96) Jordan, R. F.; LaPointe, R. E.; Bajgur, C. S.; Echols, S. F.; Willett, R. J. Am. Chem, Soc. 1987,709,4111. (97) Bochmann, M.; Lancaster, S. J. Organometallics 1993, 72, 633. (98) Latesky, S. L.; McMullen, A. K.; Niccolai, G. P.; Rothwell, I. P.; Huffman, J. C. Organometallics 1985, 4, 902. (99) Fachinetti, G.; Floriani, C.jsccc 1972, 654. (100) Massey, A. G.; Park, A. J. J. Organomet. Chem. 1964, 2, 245. (101) Scholz, J.; Rehbaum,' F.; Thiele, K. H.; Goddard, R.; Betz, P.; Kruger, C. J. J. Organomet. Chem. 1993, 443, 93. (102) Jordan, R. F.; Lapointe, R. E.; Baenziger, N.; Hinch, G. D. Organometallics 1990, 9, 1539. (103) Bochmann, M.; Karger, G.; Jagger, A. J. J. Chem. Soc, Chem. Commun. 1990, 1038. (104) Pellecchia, C; Immirzi, A.; Grassi, A.; Zambelli, A. Organometallics 1993, 72, 4473. (105) Pellecchia, C; Grassi, A.; Immirzi, A. J. Am. Chem. Soc. 1993, 75, 1160. (106) Etievant, P.; Gautheron, B.; Tainturier, G. Bull. Soc, Chim. Fr. 1978, 77, 292. (107) Jeffery, J.; Lappert, M. F.; Luong-Thi, N. T.; Webb, M.; Atwood, J. L.; Hunter, W. E. J. Chem. Soc, Dalton Trans. 1981, 1593. References on page 190 196 (108) Schock, L. E.; Brock, C. P.; Marks, T. J. Organometallics 1987, 6, 232. (109) Samuel, E.; Rausch, M. D. J. Am. Chem. Soc. 1973, 95, 6263. (110) Chaudari, M.; Stone, F. G. A. J. Chem. Soc. (A) 1966, 838. (111) Erker, G. J. Organomet. Chem. 1977,134, 189. (112) Erker, G.; Kriiger, C.; Muller, G. Adv. Organomet. Chem. 1985, 24, 1. (113) Yasuda, H.; Tatsumi, K.; Nakamura, A. Acc. Chem Res. 1985,18, 120. (114) Yasuda, H.; Kajihara, Y.; Mashima, K.; Lee, K.; Nakamura, A. Chem. Lett. 1981, 519. (115) Erker, G.; Engel, K.; Kriiger, C.; Chiang, A.-P. Chem. Ber. 1982,115, 3311. (116) Lubke, B.; Edelmann, F.; Behrens, U. Chem. Ber. 1983,116. (117) Yasuda, FL; Kajihara, Y.; Mashima, K.; Nagasuma, K.; Lee, Y.; Nakamura, A. Organometallics 1982,1, 388. (118) Kriiger, C; Muller, G.; Erker, G. Organometallics 1985, 4, 215. (119) Dorf, U.; Engel, K.; Erker, G. Organometallics 1982, 2, 462. (120) Kai, Y.; Kanehisa, N.; Miki, K.; Kasai, N.; Akita, M.; Yasuda, FL; Nakamura, A. Bull. Chem. Soc. Jpn. 1983, 56, 3735. (121) Yasuda, FL; Kajihara, Y.; Nagasuna, K.; Mashima, K.; Nakamura, A. Chem. Lett. 1980, 719. (122) Erker, G.; Engle, K.; Dorf, U.; Atwood, J. L.; Hunter, W. E. Angew. Chem., Int. Ed. Engl. 1982, 21, 914. (123) Kai, Y.; Kanehiso, N.; Miki, K.; Kasai, N.; Mashima, K.; Nagasuma, K.; Yasuda, H.; Nakamura, A. Chem. Lett. 1982, 1979. (124) Erker, G.; Berg, K.; Kriiger, C; Muler, G.; Angermund, K.; Benn, R.; Schroth, G. Angew. Chem., Int. Ed. Engl. 1984, 23, 455. (125) Temme, B.; Karl, J.; Erker, G. Chem. Eur. J. 1996, 2, 919. (126) Dioumaev, V. K.; Harrod, J. F. Organometallics 1997,16, 1452. References on page 190 197 (127) Schrock, R. R.; Shih, K. Y.; Dobbs, D. A.; Davis, W. M. J. Am. Chem. Soc. 1995,777, 6609. (128) Wengrovius, J. H.; Schrock, R. R. J. Organomet. Chem. 1981, 205, 319. (129) Hartner, F. W. J.; Schwartz, J.; Clift, S. M. J. Am, Chem. Soc. 1983,105, 640. (130) Fryzuk, M; Mao, S. S. Ff.; Zaworotko, M. J.; MacGillivray, L. R. J. Am. Chem, Soc. 1993,775,5336. (131) McClure NMR Spectroscopy Techniques; 2nd ed.; Marcel Dekker In.: New York, 1996; Vol. 21. (132) Lambert, J. B.; Shurvell, H. F.; Lightner, D.; Cooks, R. G. Introduction to Organic Spectroscopy; Macmillan Publishing Company: New York, 1987. (133) Diamond, G. M.; Jordan, R. F.; Petersen, J. L. Organometallics 1996, 75, 4045. (134) Gutekunst, G.; Brook, A. G. J. Organomet. Chem. 1982, 225, 1. (135) Unpublished results. (136) Kaminsky, W.; Bark, A.; Steiger, R. J. Mol. Catal. 1992, 74, 109. (137) Kaminsky, W.; Steiger, R. Polyhedron 1988, 7, 2375. (138) Siedle, A. R.; Hanggi, B.; Newmark, R. A.; Mann, K. R.; Wilson, T. Synthetic, Structural and Industrial Aspects of Stereospecific Polymerization; Siedle, A. R.; Hanggi, B.; Newmark, R. A.; Mann, K. R.; Wilson, T., Ed., 1995, pp 89. (139) Ewen, J. A.; Elder, M. J. Stabilisation of cationic alkyl using A1R3; Ewen, J. A.; Elder, M. J., Ed.; Eur. Pat. Appl. 426637, 426638, 1991. (140) Vizzini, J. C; Chien, J. C. W.; Babu, G. N.; Newmark, R. A. J. Polym. Sci. A, Polym. Chem. 1994, 32, 2049. (141) Herfert, N.; Fink, G. Makromol. Chem. 1992,193, 773. (142) Longo, P.; Olivia, L.; Grassi, A.; Pellechia, C. Makromol, Chem. 1989, 790, 2357. (143) Hoffmann, R. J. Chem. Phys. 1963, 39, 1397. (144) XSCANS; Siemens Analytical X-Ray Instruments Inc.: Madison, 1990. References on page 190 198 (145) Sheldrick, G. M. SHELXTL-PC; V4.1 ed.; Sheldrick, G. M., Ed.; Siemens Analytical X-Ray Instruments Inc.: Madison, WI, U.S.A., 1990. (146) Sheldrick, G. M. SHELXL-93; Sheldrick, G. M., Ed.; Institute fuer Anorg. Chemie: Goettingen, Germany, 1993. References on page 190 199 "What differentiates man from other animals is perhaps feeling rather than reason. I have seen a cat reason more often than laugh or weep. Perhaps it laughs or weeps within itself - but then perhaps within itself a crab solves equations of the second degree." Miguel De Unamuno 200 Chapter Three. Tantalum Complexes 1 Introduction 1.1 Generalities There are many homoleptic Tav amide complexes known {Ta(NR2)5; R = Me1"3, Et4, Pr^, Bu^; Ta(NMeBu)52}. On the other hand, very few tetra-amide complexes of tantalum have been reported5 {e.g., Ta(NMeBu)42}. This is in contrast to the behavior of niobium(V) which upon addition of LiNR2 gives products which contain increasing proportions of Nb™ as the size of the dialkylamido group is increased. The dearth of Ta™ derivatives may be due to the relative instability of the +4 oxidation state for Ta. Thus Ta(NMe2)5 is readily obtained from TaCl5 and LiNMe2 but the sterically demanding Tav amide complexes, Ta(NR2)5 (R = Et, Pr, Bu), decompose rapidly to the Tav imide complexes Ta(NR2)3(=NR) upon heating^, it is believed that the first step in the decomposition of M(NR2)5 (M = Nb, Ta) derivatives is the same in both cases; reductive elimination of a dialkylamino radical and formation of a Nb™ or Ta™ species. In the case of niobium a relatively stable tetrakis(dialkylamido)niobium(IV) complex is produced. However, in the case of tantalum, the tetravalent Ta(NR2)4 is unstable and reacts with the R2N radical to produce RN=Ta(NR2)3, R2NH and olefin (Scheme 3- 1). M = Nb, Ta M = Ta M(NR2)5 • M(NR2)4 • RN=M(NR2)3 + R2N" + HNR2 + olefin Scheme 3- J. Nb(IV) vs Ta(FV) amide complexes Heteroleptic amide complexes of tantalum are also known. Base-free pentacoordinated complexes such as F^atNE^) or F3Ta(NR2)2 or the hexacoordinated solvate complexes F4Ta(NEt2),py or F3Ta(NEt2)2,py have been synthesized7. References start on page 238 201 1.2 Alkyne polymerization Certain group metal complexes are active catalysts for the polymerization and cyclization of alkynes. Two mechanisms have been proposed for the polymerization of alkynes. The first one appears to proceed by way of insertion, similar to ethylene polymerization12 (Scheme 3- 2), to give an alkenyl propagating species. HC LnM. CH R H * CN R CH LnM H C* CRH H C^ HC CRH CH Scheme 3- 2. Polymerization of alkynes, insertion mechanism The second mechanism proceeds via an alkylidene complex (Scheme 3- 3). M = CHR + * * 'RC=CR' M CHR 'R / \ •R FT M C 'R CHR Scheme 3- 3. Polymerization of alkynes, alkylidene mechanism A clear distinction can be drawn between these two mechanisms. Scheme 3- 2 predicts that the two carbons of a given monomer (C*) unit will end up doubly bonded to one another in the resulting polymer. According to the mechanism in Scheme 3- 3 these same carbons will be connected by a single bond. Through the use of 13C NMR spectroscopy, it was confirmed that the polymer formed with the MoCl5/Ph4Sn system contains labeled carbons joined by C-C single References start on page 238 202 bonds consistent with the alkylidene mechanism. In contrast, the titanium-based catalyst Ti(OBu)4/Et3Al gives a polymer in which labeled carbons are separated by C=C double bonds as expected for an insertion-type mechanism13"1^. Metal alkyl complexes with a formal d2 configuration are known to insert alkynes, however, the alkenyl complexes are typically reluctant to engage in further insertions. For example, the d2 r|2-alkyne complex Tp*NbCl(CH2CH3)(ri2-PhC=CCH2CH3) (Tp* = hydrotris(3,5-dimethyl-pyrazolyl)borate) readily inserts the coordinated alkyne PhC^CCH2CH3, but stops short of inserting additional alkyne.16 Precursor complexes of the type LnTa(r)2-RG=CR)X (A, X = alkyl, hydride, or halide),1^ where the metal is formally in the +3 oxidation state, are ideally suited for studying the insertion mechanism. The formation of metallacyclopentadiene complexes resulting from the coupling of alkynes impedes the coordination insertion process making the choice of ancillary ligand system (Ln) for complexes of type A critical. For instance, r)2-alkyne complexes are obtained with bis(cyclopentadienyl) templates (e.g., Cp2Ta(ri2-RC=CR)X) 18-26 and mono(pentamethylcyclopentadienyl) ligation (e.g., Cp*Ta(r|2-RC5CR)X2)27-29i while less coordinatively saturating alkoxide ligands yield metallacycles (e.g., (DIPP)3Ta(C4Et4), DIPP = 2,6-diisopropylphenoxide)30>3l. Interestingly, the reduction of (DIPP)2TaCl3 in the presence of bis(trimethylsilyl)acetylene affords the r|2-alkyne complex (DIPP)2ClTa(Tf-Me3SiC=CSiMe3)32. References start on page 238 203 2 Results and Discussion 2.1 Pyridine diamide complexes of tantalum The silylated diamines la-e react with TaCl5 to form the corresponding trichloride complexes (2a-e) (eq. 1). The eliminadon of ClSiMe3 provides the necessary driving force for the reaction and was detected by 'H NMR spectroscopy. / N r=^ SiMe. 80°c/c6H6 /=\ \ >CI (1) + TaCI5 SiMe3 -2CISiMe3 / N \ n a, R = 2,6-diisopropylphenyl 1a-e b, R = 2,6-dimethylphenyl 2a-e c, R = 2,4,6-trichlorophenyl d, R = cyclohexyl e, R = isopropyl The 'H NMR spectrum of complex 2a displays a singlet at 5.84 ppm for the methylene (C//2N) protons of the ligand, consistent with the C2v symmetry and meridional conformation of the ligand. A facial coordination of the ligand would yield a complex with Cs symmetry and the methylene (CH2N) protons would appear as an AB pattern. Compound 2a also displays diastereotopic isopropyl methyl groups. This inequivalence has been interpreted as a consequence of restricted rotation around the N-aryl C, bond. The proton NMR spectrum of compound 2a remains unchanged at 80"C. Similarly, the 'H NMR spectra of complexes 2b-e display a singlet for the ligand methylene protons (C//2N) at approximately 5.8 ppm. Compounds 2a-c can be alkylated with 3 equivalents of MeMgBr or MeLi to give the trimethyl derivatives 3a-c (eq. 2). References start on page 238 204 R -30 'Cl Et20 2a-c R a, R = 2,6-diisopropylphenyl b, R = 2,6-dimethylphenyl c, R = 2,4,6-trichlorophenyl 3a-c R The 'H NMR spectra of complexes 3a-c show two different Ta-Me groups, one trans to the pyridine ring of the ligand and two cis. The C2v symmetry and the restricted rotation of the N-aryl Cips„ bond observed with complex 2a are retained upon alkylation. Other metathetical reactions involving larger alkylating reagents (i.e., PhCH2MgCl and Me,SiCH2Li) yield intractable materials. Certain Ta(V) or Nb(V) complexes which contain at least two neopentyl groups are known to eliminate neopentane, affording neopentylidene complexes, by a process called a-hydrogen abstraction33-37 jn a similar way, Ta(V) and Nb(V) complexes that contain two or more Me3SiCH238,39 and PhCH236,37,40-42 gr0ups also yield alkylidene complexes. However, unlike neopentylidene complexes, benzylidene and trimethylsilylmethylidene compounds are often unstable and decompose under the reaction conditions. The monocyclopentadienyl complex Ta(r|5-C5H5)(CHCMe3)Cl234,37 w^ the dicyclopentadienyl derivative Ta(ri5-C5H5)2(CHCMe3)Cl37 are amongst the best studied examples. A similar type of reaction is proposed to account for the difficulties associated with the synthesis of the tris(benzyl) and tris(trimethylsilylmethyl) complexes (Scheme 3- 4). The a-hydrogen transfer can take place between two adjacent alkyl groups to give the alkylidene alkyl complex (Scheme 3- 4, i). Another possible pathway involves a-hydrogen transfer to one of the amide groups to give an alkylidene dialkyl complex with a partly protonated ligand moiety (Scheme 3- 4, ii). The same reaction can then take place a second time to completely protonate the ligand and to give a potentially unstable dialkylidene alkyl complex. References start on page 238 205 Scheme 3- 4. Alkylidene formation 2.2 Reduction chemistry of pyridine diamide complexes of tantalum The two-electron reduction of the trichloride complexes 2a,b,d,e with excess Na/Hg (1% or 2%) in the presence of alkynes affords the pseudo 5-coordinate Ta(III) derivatives (Scheme 3-5). A single low-field (8 ca. 238 ppm) acetylenic carbon resonance is observed in the 13C{'H} NMR spectra of complexes 4a,b, 7a,b and 8a, suggesting that the alkyne is acting as 4-electron donor43-45 jne three main orbital interactions involved in the overall bonding are described in Figure 3- 1. M M(a)-<-7ij M(dTr.)rtj * M(d7t) n2 Figure 3- 1. 4 e interaction of an alkyne with a metal References start on page 238 206 Scheme 3- 5. Reduction of the trichloride complexes 2o,b,d,e The methylene protons of the ligand (C//2N) appear as an AB quartet in the 'H NMR spectra of the rf-alkyne complexes. This indicates asymmetry about the N3-plane of the ligand. As a result of the Cs symmetry and the restricted rotation around the N-aryl Cipso bond two isopropyl methine and four isopropyl methyl resonances are observed in the proton and carbon NMR spectra of complexes 4a, 7a, 8a, 9a and 10a. Free rotation of the alkyne on the NMR timescale in complexes 4a,b, 7a,b and 8a is advanced since both ends of the coordinated alkynes are equivalent by 'H and 13C{'H} NMR References start on page 238 207 spectroscopy. This process equilibrates the diastereotopic ethyl methylene protons in (BDPP)TaCl(r)2-EtC^CEt) and causes them to appear as a quartet in the proton NMR spectrum. It is not possible to determine by spectroscopic means if the alkyne is freely rotadng in complexes 9a and 10a. Interestingly, the presence of two acetylenic resonances in the 13C{'H} spectra of complexes 4d and 5e indicates that the rotation of the alkyne is inhibited. This is attributed to the different steric requirements of the alkyl ligands compared to the 2,6-disubstituted aryl ligands. The 2,6-substituted phenyl rings in the BDPP and BDMP ligands block both faces of the N3 plane and create a protective "pocket" trans to the pyridine and rotation of the alkyne located, trans to the pyridine is not restricted (Figure 3- 2,1). On the other hand, rotation of the alkyne in complexes 4d and 5e results in strong steric interactions with the alky] groups of the ligand (Figure 3- 2, II). Consequently, rotation of the alkyne is restricted and two signals are observed for the acetylenic carbons in the 13C{'H} NMR spectra. (I) («) Figure 3- 2. Alkyl vs 2,6-substitutedphenyl ligands References start on page 238 208 2.3 Metallocene vs pyridine diamide tantalum alkyne complexes It is interesting to compare metallocene-based and pyridine diamide tantalum alkyne complexes. The similarides between the fronder orbitals of the Cp2M fragment and the PyN3M fragment have been discussed in detail in Chapter 2. Complexes of the type Cp2MX(r|2-alkyne) (M = Nb, Ta; Cp = "n5-C5H521-26, ri5-C5H4Me20, Ti^H/Pr1^ X = H, alkyl, halide) are known and display high-field rf-alkyne carbon resonances (C=C, 140 ppm) characteristic of an alkyne behaving as a two-electron donor43-45 jn contrast, the rf-alkyne (C=C) carbons are observed at ca. 240 ppm in complexes 4a,b, 7a,b and 8a. The difference in electron donating ability of the two ancillary ligand systems may explain the marked difference in 13C chemical shift. The pyridine diamide ligand can be viewed as an electron deficient cyclopentadienyl equivalent donating 8-electrons to the metal centre compare to 12-electrons for two Cp ligands. As a result, the formal electron count for the defragment PyN3TaCl is 12 while the d2-Cp2TaCl is formally a 16-electron fragment. The more electrophilic metal bearing the pyridine diamide ligand can therefore accept more electron density from the alkyne, hence a higher chemical shift is observed for the r|2-alkyne carbons (C=Q. Comparatively, the low-field 13Calkyne resonance (ca. 220 ppm) observed for the mono(cyclopentadienyl) complexes (r)5-C5Me5)MCl2(RC=CR)28,46 js consistent with the alkyne acting as a 4-electron ligand and the 12 electron count of the d2-CpTaCl2 fragment. The steric requirements of the pyridine alkyl-amide ligands are comparable to those observed with the metallocene ancillary ligands. For example, the 'H NMR spectrum of Cp2TaEt(MeC^CH)26 suggests the structure indicated in Figure 3- 3 in which the alkyne C=C bond lies in the same plane as the Ta atom and the ethyl group. Restricted rotation about the Ta-(rf-C^C) bond was confirmed by the presence two ri2-propyne methyl resonances (exo, 2.91 ppm; endo, 2.74). This is similar to the behavior observed with complexes 4d and 5e and two low-field acetylenic resonances are obtained in the 13C NMR spectrum. References start on page 238 209 exo endo Figure 3- 3. exo and endo conformation of Cp2TaEt(MeCsCH) 2.4 Crystal structure of (BDPP)Ta(r|2-PrC=CPr)CI Yellow single crystals of (BDPP)Ta(r|2-PrC=CPr)Cl (4a) suitable for an X-ray analysis were grown from a saturated ether solution at -30°C. The molecular structure of complex 4a is shown in Figure 3- 4, and selected bond distances and angles are given in Table 3- 1. The complete crystallographic data can be found in the Appendix. Table 3- L Selected Bond Distances (A) and Angles (deg) for 4a Bond Distances Ta(l) - N(l) 2.053 (6) Ta(l) -C(32) 2.062 (7) Ta(l) -N(3) 2.033 (6) Ta(l) -C(36) 2.085 (7) Ta(l) -N(2) 2.255 (6) C(32) - C(36) 1.287 (11) Ta(l) -Cl(l) 2.361 (2) Acet* -Ta 1.97 Bond Angl< es N(3)- Ta(l) - N(l) 137.2 (2) C(36) - C(32) - C(33) 132.6 (8) N(2)- Ta(l) - Cl(l) 93.7 (2) C(32) - C(36) - C(37) 137.2 (8) Acet* = midpoint of C(32) - C(36) The geometry around the Ta centre can be best described as a distorted square pyramid with the three nitrogen atoms of the ligand and the midpoint of the alkyne forming the base of the square pyramid and the chloride {Cl( 1)} occupying the apical position. References start on page 238 210 Figure 3- 4. Molecular structure of (BDPP)Ta(Ta(rf-PrC=CPr)Cl (4a) deduced from single crystal X-ray analysis References start on page 238 211 The 4-octyne unit is located trans to the pyridine of the BDPP ligand and is rotated by 50° with respect to the Cl(l)-Ta(l)-N(2) plane (Figure 3- 4). The bond distances in the Ta-alkyne moiety are comparable to those reported for other mononuclear Ta(IU) alkyne complexes29,31,47 Each amide nitrogen is sp2-hybridized as evidenced by the sum of the angles about each nitrogen {N(l) = 359.5° and N(3) = 359.9°}. The reduction of complex 2a in the presence of the terminal alkynes PhC=CH and Me3SiOCH affords the rp-alkyne complexes 9a and 10a, respectively. Complexes 9a and 10a necessarily display two low-field acetylenic resonances in the 13C{'H} NMR spectra. The 'H NMR spectra of complexes 9a (Figure 3- 5) and 10a display low-field resonances for the coordinated r\2-HC=CR. The AB quartet observed for the ligand methylene protons (NC//2) as well as the two isopropyl methine and for isopropyl methyl signals are consistent with Cs symmetry and restricted rotation about the 2,6-diisopropylphenyl-nitrogen bond. The 'H NMR spectrum of the hydrolysis (D20) products of compound 9a is consistent with a formal metallacyclopropene Tav species (eq. 3). References start on page 238 212 References start on page 238 213 Interestingly, the reduction of complex 2e in the presence of an excess of the terminal acetylene Me3SiC=CH affords the metallacyclopentadiene alkynyl complex (iPAP)Ta{C4oc-a'(Me3Si)2H2}(C=CSiMe3) (6e) (eq. 4). The a,a' substitution pattern for the metallacycle is proposed based on the two low-field doublets (©/®) observed in the 'H NMR spectrum of complex 6e (Figure 3- 6). Moreover, the presence of three distinct SiMe3 in the 'H and 13C{'H} NMR spectra in consistent with the proposed structure. The alkynyl fragment is formed via the metathesis of one of the chloride with NaC=CSiMe3. It has already been reported that Na and other alkali metals react with acetylene to give NaC^CH48. 2e R = isopropyl 6a In contrast, compounds 4a,b,d, 7a,b, 8-10a show no evidence of metallacycle formation even under forcing conditions (excess alkyne, 110 °C). Furthermore, the coordinated alkynes do not exchange with free alkyne. For example, no reaction occurs between compound 4a and 50 equivalents of phenylacetylene at 80 "C. References start on page 238 21 References start on page 238 215 2.5 Reactivity of the V-alkyne complexes Complex 4a can be alkylated with 1 equivalent of MeMgBr to give (BDPP)Ta(r|2-PrC=CPr)Me (5) (eq. 5). The 'H and I?C NMR spectra of compound 12a are similar to those obtained for compound 4a with additional resonances for the Ta-CH3 group at 0.44 and 37.94 ppm, respectively. The asymmetry about the N3-Ta plane as well as the restricted rotation around the N-aryl Cipsn bond are retained. The coordinated 4-octyne in complex 12a does not insert into the Ta-Me bond at elevated temperatures (110 °C), even in the presence of PMe3. The methyl complex 12a reacts with the Lewis acid B(C6F5)349 in the presence of excess alkyne to afford the cationic tantalacyclopentadiene complex 13a (eq. 6). Compound 13a is only slightly soluble in benzene and decomposes within hours in dichloromethane. 0 /R MeB(C6F5)3 (BDPP)Ta(n2-PrCCPr)Me Pentane/.30^ /=^)®,JwPr <6> B(CIF5)3 .PrCCPr* S^j'S^p, R 13a R = 2,6-diisopropylphenyl References start on page 238 216 The 'H NMR spectrum of complex 13a displays a singlet for the ligand methylene protons (NC//2) as expected for a complex with C2v symmetry. Restricted rotation of the phenyl rings is maintained as evidenced by the two isopropyl methyl resonances. Compound 13a does not react further with excess 4-octyne (25 °C). Decomposition to free ligand and insoluble products occurs upon heating (60 °C) of a benzene solution containing 13a and 50 equivalents of 4-octyne. Complex 12a reacts with excess phenylacetylene in toluene at 110 °C to give methane (confirmed by 'H NMR spectroscopy) and the metallacycle 18a in quantitative yield by 'H NMR spectroscopy (eq. 7). Two low-field acetylenic resonances (5 220.26 and 189.90 ppm) are observed in the 13C{'H} NMR spectrum of complex 18a. Moreover, the 'H NMR spectrum displays resonances for two inequivalent propyl chains and two distinct phenyl groups. The ligand resonances in the proton and carbon NMR spectra of complex 18a are consistent with Cs symmetry in solution. The solid state structure of complex 18a was determined by single crystal X-ray analysis. The molecular structure of complex 18a can be found in Figure 3- 7 and relevant bond distances and angles in Table 3- 2. The complete crystallographic data can be found in the Appendix. References start on page 238 217 References start on page 238 218 Table 3- 2. Selected Bond Distances (A) and Angles (deg) for 18a Bond Distances Ta-N(l) 2.006(11) Ta-N(2) 2.005(10) Ta-N(16) 2.225(6) Ta-C(l) 2.075(14) Ta-C(2) 2.030(12) Ta-C(6) 2.19(2) C(l)-C(2) 1.30(2) C(2)-C(3) 1.45(2) C(3)-C(4) 1.33(2) C(4)-C(5) 1.51(2) C(5)-C(6) 1.37(2) Bond Angles N(l)-Ta-N(2) 137.9(2) N(l)-Ta-N(16) 71.4(4) N(2)-Ta-N(16) 72.6(4) N(l)-Ta-C(6) 102.8(5) N(2)-Ta-C(6) 100.2(5) N(16)-Ta-C(6) 93.0(4) Ta-C(6)-C(5) 127.2(10) C(6)-C(5)-C(4) 129.9(13) C(5)-C(4)-C(3) 122.1(13) C(4)-C(3)-C(2) 116.4(12) C(3)-C(2)-C(l) 140.0(13) The coordination geometry of tantalum in compound 18a is very similar to that in complex 4a. The acetylide group {C(l)-C(2)} resides in the basal plane of a distorted square pyramid (the octyne unit is in this position in compound 4a), while the alkenyl carbon (C(6)} occupies the apical position {Cl(l) occupies the apical position in 4a}. As a result of the metallacycle restraints, the acetylenic unit in compound 18a is only rotated about 12° relative to the C(6)-Ta-N(16) plane. Comparatively, the 4-octyne in complex 4a is rotated by 50° relative to the same plane. The alternating short and long bonds observed in the metallacyclic unit (Figure 3- 7, bottom) are consistent with the coupling of two alkyne molecules and an acetylide. References start on page 238 219 Compound 18a appears to result from the insertion of coordinated alkyne into a Ta-C^CPh unit (B, Scheme 3- 6), followed by a 2,1-insertion of phenylacetylene into the newly formed alkenyl moiety (C, Scheme 3- 6). Ph Ar = 2,6-'Pr2C6H3 Scheme 3- 6. Coordination/insertion mechanism The 2,1-insertion of phenylacetylene likely minimizes the interaction between the phenyl group and the propyl chains of the octyne. The Ta-C^CPh unit is likely formed by the protonolysis of the methyl group in complex 12a by PhC=CH. A series of acetylide complexes were prepared in order to demonstrate that these compounds are intermediates in this reacdon. Compound 4a reacts cleanly with LiC^CR in ether at -30 °C to give the acetylide derivatives 14-17a (eq. 8). References start on page 238 220 ^NAr Pr ^NAr ROCLi /= \ Et20 / -30 "C Pr Ar = 2,6-'Pr2C6H3 (8) 14a, R = Ph 15a, R = o-SiMe3C6H4 16a, R = Bu 17a, R = SiMe3 The 'H NMR spectra of compounds 14-17a display an AB quartet at approximately 5.1 ppm for the ligand methylene protons (NC//2), again indicating asymmetry about the Ta-N3 plane of the ligand. The low-field acetylenic carbon resonances observed in the 13C{'H} NMR spectra of complexes 14-17a are consistent with the octyne acting as a 4-electron donor^^. The reaction of the phenylacetylide derivative 14a with excess phenylacetylene in toluene (110°C) affords the metallacycle 18a in quantitative yield by proton NMR spectroscopy. In a similar way, the acetylide complexes 16a and 17a react with 1-hexyne and trimethylsilylacetylene, respectively, to give the metallacyclic compounds 19a and 21a (eq. 9). However, compound 14a does not react with internal alkynes (3-hexyne, 4-octyne) under similar conditions. Pr R r-NArjf Pr ^-NAr Pr /—NAr/ x_ R'C=CH /=( \ / Pr —• W^/H^ ^—NAr R 18a,R = R' = Ph 19a, R = R' = Bu Ar = 2,6-'Pr2C6H3 20a, R = Bu, R' = Ph 21a, R = R'= SiMe3 22a, R = SiMe3, R' = Ph (9) References start on page 238 221 The 'H NMR resonances attributable to the BDPP ligand in complex 19a are very similar to those observed for complex 18a which might indicate that the two complexes are isostructural. In contrast, the 'H NMR spectrum of compound 21a displays resonances characteristic for a complex with Cj symmetry (Cs symmetry is observed in solution for complexes 18a and 19a). The observed C, symmetry may be explained by the steric demand of the acetylene-trimethylsilyl group. This causes the adjacent ligand aryl groups to twist about the N-C; bond to avoid steric interactions. The formation of only one of the two possible regioisomers of the metallacycle (1,2-and 2,1-insertion) is indicated by the presence of only two trimethylsilyl in the 'H and 13C{'H} NMR spectra of compound 21a. Compounds 16a and 17a react with excess phenylacetylene to give the corresponding mixed metallacycle complexes 20a and 22a, respectively. There is no evidence for the formation of complex 18a which suggests that the starting acetylide unit is not protonated by the incoming PhCnCH and is retained in the final product. Similarly to complex 21a, complex 22a which bears the bulky trimethylsilyl group on the r|2-alkyne displays C, symmetry in solution. In both cases, the 'H NMR spectrum remains unchanged at 80 °C. Surprisingly, compound 15a which bears the bulky C=C(o-SiMe3)Ph group does not react with HC^CPh, HC=CSiMe3 or HC^CBu, even at elevated temperatures (110 °C). Modeling studies^ suggest that rotation about the Ta-C=C bond is inhibited by the Me3Si group. Moreover, these studies also suggest that the endo isomer is more stable than the exo conformer. The exo conformation results in strong steric interactions between the Me3Si group and the isopropyl groups of the ligand. On the other hand, the Me3Si group in the endo conformer is directed toward the alkyne and may prevent approach of the two units. References start on page 238 222 // Pr' Pr SiMe3 endo Ar = 2,6-'Pr2C6H3 exo Figure 3- 8. endo and exo conformation Attempts to trap the proposed intermediate alkenyl species (I, Scheme 3- 6) were unsuccessful. No reaction occurs between compound 14a and a variety of Lewis bases (PMe3, NEt3, py) at 110 °C. It appears that the relatively strong interaction between the alkyne unit of the metallacycle and tantalum prevents this system from undergoing multiple insertions of alkyne. Attempts to metathesize the chloride in complex 4a,b with a phenyl, vinyl or -C=N group were unsuccessful. Another possible mechanism for the formation of complexes 18-22a involves a metallacyclopentadiene acetylide intermediate (Scheme 3- 7) as observed with the smaller (iPAP) ligand (compound 6e, vide supra). We see no evidence of metallacyclopentadiene formation between compounds 4a,b and HC^CPh at elevated temperatures (110 °C). Although there are numerous reports of alkyne insertions into transition metal-hydrogen bonds23-26i the are few examples of alkyne insertion into a transition metal-alkyl bond. Neutral References start on page 238 'R Scheme 3- 7. Metallacyclopentadiene acetylide mechanism 223 scandocene51, cationic titanocene52, and cationic zirconocene53,54 complexes readily insert alkyne to give T]1-vinyl species. However, the intermediate alkyl alkyne complexes are not detected. It has recendy been reported that Tp*Nb(Cl)(CH2R)(PhC=CR') (eq. 10, I) (Tp* = hydrotris(3,5-dimethylpyrazolyl)borate) reacts with excess alkyne to yield the rj'-alkenyl complex (eq. 10, II)16. (10) (I) (II) The pyridine diamide system goes one step further and inserts two equivalents of alkyne into a metal-carbon bond. References start on page 238 224 3 Conclusions The elimination of Me3SiCl provides a suitable driving force for the synthesis of pyridine diamide complexes of Tav (2a-e). The reduction of the trichloride complexes 2a,b in the presence of excess alkyne affords the corresponding rf-alkyne complexes. X-ray analysis of the r|2-octyne complex 4a revealed a square pyramid geometry with the alkyne located in the basal plane. The reduction of the pyridine (alkyl)amide complexes 2c,d in the presence of the bulky alkynes Me3SiCsCSiMe3 and PrC=CPr affords the expected rf-alkyne tantalum complexes. Interestingly, the reduction of complex 2c in the presence of excess Me3SiC=CH affords the a,a'-tantalacyclopentadiene(acetylide) complex 6e. The high temperature reaction of complex 4a with excess PhC=CH affords the doubly inserted products 18a. The structure of complex 18a was determined by X-ray analysis and is very similar to the structure of complex 4a. The reaction appears to proceed via insertion of coordinated alkyne into a Ta-C=CR bond. In a similar way, the acetylide complexes 14-17a also insert various terminal alkynes to give the doubly inserted complexes 18-22a. Attempts to induce further alkyne insertion were unsuccessful. References start on page 238 225 4 Experimental Details General Details. See chapter one for general details. (BDPP)(SiMe3)2 (la), (BDMP)(SiMe3)2 (lb), (CyAP)(SiMe3)2 (Id) and (iPAP)(SiMe3)2 (le) were prepared as described in chapter one. Tantalum(V) chloride was purchased from Alfa and used as received. Diphenylacetylene, phenylacetylene, 3-hexyne, 4-octyne and methylmagnesium bromide were purchased from Aldrich and used as received. The ortho-trimethylsilylphenylacetylene was prepared using a previously reported synthesis55. The lithium actetylides were prepared from the corresponding acetylene and n-BuLi in hexanes. 2,6-[R(Me3Si)NCH2]2-NC5H3, (R = 2,4,6-trichIorophenyl) (TCPP)(SiMe3)2 (lc). A THF (150 mL) solution of Li(Me3Si)NR (10.20 g, 37.15 mmol) was added slowly to a THF (100 mL) solution of 2,6-bis(bromomethyl)pyridine (4.650 g, 17.55 mmol) at -78 °C. The mixture was allowed to warm to room temperature and stirred for 12 h. The solution was quenched with a saturated NaHC03 solution (100 ml) and extracted with ether (3 x 150 mL). The solvent was removed in vacuo to yield a yellow-brown viscous liquid. The oil was then dissolved in hot hexanes and cool to -30 °C. White crystalline lc was isolated by filtration and dried under vaccum (8.650 g, 13.51 mmol, 77 %). 'H NMR 6 7.01 (s, 4H, Ar), 7.01 (t, 1H, py), 6.76 (d, 2H, py), 4.24 (s, 4H, NC//,), 0.16 (s, 18H, SiMe,). 13C{'H} NMR 5 158.71, 143.35, 138.11, 136.09, 130.55, 128.59, 55.39, 0.25. MS (EI) m/z 639.000 (M+). Calcd for C24H29N3Si235Cl537Cl : 639.000. /n£?r-(BDPP)TaCl3 (2a). Solid TaCl5 (2.670 g, 7.454 mmol) was added in small portions to a benzene (150 mL) solution of la (4.087 g, 6.768 mmol) at 23°C. The turbid solution immediately turned bright yellow and was heated to 80°C for 12h. The volatile components were removed under vacuum and the resulting solid dissolved in THF (50 mL). The solution was filtered through Celite and the solvent removed in vacuo. The resulting solid was washed with hexanes (3 x 50 mL) to yield a bright yellow crystalline solid 2a (4.204 g, 5.658 References start on page 238 226 mmol, 84%). IH NMR 8 7.14 (m, 6H, Ar), 6.84 (t, IH, py), 6.38 (d, 2H, py), 5.84 (s, 4H, NC/72), 3.80 (sept, 4H, C#Me2), 1.52 (d, 12H, CHM<?2), 1.12 (d, 12H, CHMe2). BCpH} NMR 8 161.64, 148.84, 146.56, 139.66, 125.35, 122.28, 117.51, 71.78, 28.89, 27.57, 23.64. Anal. Calcd for C31H41N3TaCl3: C, 50.11; H, 5.56; N, 5.66. Found: C, 50.25; H, 5.68; N, 5.11. mer-(BDMP)TaCl3 (2b). The preparation of compound 2b is identical to that of 2a. Solid TaCl5 (1.000 g, 2.792 mmol) and compound lb (1.370 g, 2.797 mmol) yielded a bright yellow powder (2b) (1.321 g, 2.094 mmol, 75%). 'H NMR (CD2C12) 8 6.16 (t, IH, py), 6.64 (d, 2H, py), 7.14 (m, 6H, Ar), 5.98 (s, 4H, NC//2), 2.38 (sept, 4H, C//3). 13C{'H} (CD2C12) NMR 8 158.31, 145.04, 138.10, 133.66, 126.74, 125.27, 116.14, 66.81, 17.15. mer-(TCPP)TaCI3 (2c). The preparation of compound 2c is identical to that of 2a. Solid TaCl5 (1.298 g, 3.624 mmol) and compound lc (2.300 g, 3.591 mmol) gave a bright yellow powder (2c) (2.750 g, 3.520 mmol, 98 %). The high insolubility of complex 2c limited its characterisation by NMR spectroscopy. Anal. Calcd for C13H21Cl3N3Ta: C, 30.82; H, 3.18; N, 8.29. Found: C, 30.42; H, 4.20; N, 8.57. mer-(CyAP)TaCl3 (2d). The preparation of compound 2d is identical to that of 2a. Solid TaCl5 (0.602 g, 1.681 mmol) and compound Id (0.750 g, 1.682 mmol) gave a bright yellow powder (2d) (0.521 g, 0.888 mmol, 53 %). 'H NMR 8 6.94 (t, IH, py), 6.45 (d, 2H, py), 5.63 (tt, 2H, NC//), 5.29 (s, 4H, NC/72), 2.44 (d, 4H, Cy), 1.75 (d, 4H, Cy), 1.45 (m, 6H, Cy), 1.00 (m, 6H, Cy). nC{lH} NMR 8 162.06, 138.63, 117.73, 61.08, 60.55, 30.61, 26.71, 26.11. /ner-(iPAP)TaCl3 (2e). The preparation of compound 2e is identical to that of 2a. Solid TaCl5 (1.077 g, 3.007 mmol) and compound le (1.000 g, 2.734 mmol) gave a bright yellow powder (2a) (0.698 g, 1.378 mmol, 50 %). 'H NMR 8 6.82 (t, IH, py), 6.32 (d, 2H, References start on page 238 227 py), 5.97 (sept, 2H, NC#Me2), 5.14 (s, 4H, NC//2), 1.17 (d, 12H, NCHMe2). 13C{'H} NMR 8 166.23, 138.41, 117.65, 59.54, 51.84, 19.60 mer-(BDPP)TaMe3 (3a). To a diethylether (25 mL) solution of compound 2a (0.401 g, 0.538 mmol) was added 3.3 equiv. of MeMgBr (0.54 mL, 3.0 M, 1.6 mmol) at -78 °C. The solution was stirred for 12 h. The solvent was removed in vacuo. The resulting solid was extracted with toluene (3 x 10 mL) and filtered through Celite to give a bright yellow solution. The solvent was removed in vacuo, the solid dissolved in a minimum amount of diethylether, and cooled to -30°C for 12 h. Yellow crystalline 3a was isolated by filtration and dried under vacuum (0.310 g, 0.455 mmol, 83%). 'H NMR 8 7.14 (m, 6H, Ar), 6.84 (t, 1H, py), 6.63 (d, 2H, py), 5.04 (s, 4H, NC//2), 3.56 (sept, 4H, C//Me2), 1.42 (d, 12H, CUMe2), 1.39 (s, 3H, TaAfe), 1.16 (d, 12H, CHMe2), 0.86 (s, 6H, TaMe). 13C{'H} NMR 8 161.27, 151.30, 145.28, 138.38, 126.36, 124.49, 116.78, 71.14, 69.09 (TaCH,), 65.80 (TaCH3), 28.44, 27.46, 23.95. Anal. Calcd for C34H50N3Ta: C, 59.90; H, 7.39; N, 6.16. Found: C, 59.43; H, 7.35; N, 5.73. mer-(BDMP)TaMe3 (3b). The preparation of compound 3b is identical to that of 3a. Compound 2b (0.100 g, 0.159 mmol) and MeMgBr (0.29 mL, 1.8 M, 0.522 mmol) yielded orange crystalline 3b (0.074 g, 0.130 mmol, 82%). 'H NMR (CD2C12) 8 7.98 (t, 1H, py), 7.45 (d, 2H, py), 7.04 (d, 4H, Ar), 6.96 (m, 2H, Ar), 5.15 (s, 4H, NO/2), 2.24 (s, 12H, Me), 0.57 (s, 3H, TaAte), 0.19 (s, 6H, TaMe). 13C{'H} NMR (CD2C12) 8 162.03, 151.98, 139.47, 135.43, 128.98, 125.38, 118.10, 68.81, 66.54 CTaMe), 61.78 CTdMe), 18.94. mer-(TCPP)TaMe3 (3c). The preparation of compound 3c is identical to that of 3a. Compound 2c (0.300 g, 0.384 mmol) and MeMgBr (1.0 mL, 1.34 M, 1.3 mmol) gave orange crystalline 3c (0.180 g, 0.250 mmol, 65 %), 'H NMR 8 7.09 (s, 4H, Ar), 6.81 (t, 1H, py), 6.32 (d, 2H, py), 4.70 (s, 4H, NC//2), 1.50 (s, 3H, TaMe), 1.03 (s, 6H, TaMe). 13C{'H} NMR 8 161.33, 149.34, 138.84, 135.12, 129.30, 128.85, 117.25, 74.30, 69.76, 66.84. (BDPP)Ta(r)2-PrCHCPr)Cl (4a). A toluene (30 mL) solution of compound 2a References start on page 238 228 (0.500 g, 0.673 mmol) and 4-octyne (0.297 g, 2.70 mmol) was added to an excess of Na/Hg amalgam (0.460 g Na, 20.0 mmol; 46.0 g Hg). The mixture was stirred for 12h. The solution was decanted from the amalgam and filtered through Celite. The solvent was removed in vacuo to yield an orange-brown solid. The solid was dissolved in a minimum amount of diethylether and cooled to -30°C for 12h. Yellow crystalline 4a was isolated by filtration and dried under vacuum (0.401 g, 0.513 mmol, 75%). IH NMR 5 7.19 (t, 2H, Ar), 7.13 (d, 4H, Ar), 6.85 (t, IH, py), 6.39 (d, 2H, py), 5.12 (AB quartet, 2jm = 20.1 Hz, 4H, NC/72), 3.79 (sept, 2H, C/7Me2), 3.15 (sept, 2H, C//Me2), 2.51 (m, 4H, =CCH2), 1.46 (d, 6H, CHMe2), 1.34 (m, 4H, C//2CH3), 1.32 (d, 6H, CHMe2), 1.24 (d, 6H, CHMe2), 1.01 (d, 6H, CHMe2), 0.84 (t, 6H, CH2C//3). 13C{1H} NMR 8 237.01 (C=C), 160.77, 154.41, 145.19, 142.96, 138.41, 125.49, 124.32, 123.57, 116.99, 70.95, 40.02, 28.60, 27.95, 26.66, 25.76, 24.61, 23.80, 21.94, 15.45. Anal. Calcd for C39H55N3TaCl: C, 59.88; H, 7.09; N, 5.37. Found: C, 59.62; H, 7.19; N, 5.16. (BDMP)Ta(r|2-PrC=CPr)Cl (4b). The preparation of compound 4b is identical to that of 4a. Compound 2b (0.250 g, 0.396 mmol), 4-octyne (0.153g, 0.500 mmol) and excess Na/Hg amalgam (0.090 g Na, 3.960 mmol; 9.0 g Hg) gave yellow crystalline 4b (0.190 g, 0.219 mmol, 55 %). 'H NMR 8 7.03 (d, 4H, Ar), 6.91 (t, IH, py), 6.90 (t, 2H, Ar), 6.42 (d, 2H, py), 4.76 (AB quartet, 2JHH = 20.1 Hz), 2.65 (t, 4H, C//2CH2Me), 2.58 (s, 6H, Me), 2.12 (s, 6H, Me), 1.48 (q, 4H, CH,C/72Me), 0.83 (t, 6H, CH2CH,Me). I3C{'H} NMR 8 237.60, 160.70, 155.395, 138.13, 135.03, 133.11, 128.67, 124.76, 117.25, 67.34, 39.43, 22.45, 19.57, 19.05, 15.19. (CyAP)Ta(r|2-PrC=CPr)Cl (4d). The preparation of compound 4d is identical to that of 4a. Compound 2d (0.250 g, 0.426 mmol), 4-octyne (0.150 g, 0.490 mmol) and excess Na/Hg amalgam (0.098 g Na, 4.260 mmol; 9.80 g Hg) gave yellow crystalline 4d (0.187 g, 0.228 mmol, 53 %). ;H NMR 8 6.99 (t, IH, py), 6.46 (d, 2H, py), 4.66 (AB quartet, 2]m = 20.1 Hz, 4H, NC//2), 3.50 (m, 2H, NC//), 3.48 (m, 2H, C/72CH2Me), 2.86 (t, 2H, C//2CH2Me), 2.19 (m, 2H, CH2C/72Me), 2.05 (d, 2H, Cy), 0.80-1.80 (m, 23H, Pr and Cy), References start on page 238 229 0.68 (t, 3H, CH2CH2Me). 13C{'H} NMR 8 201.95, 195.10, 165.31, 137.34, 128.93, 116.75, 59.85, 52.93, 50.26, 37.80, 30.94. 30.12, 27.17, 26.83, 26.57, 24.60, 23.99, 15.46, 14.60. (iPAP)Ta(Me3SiOCSiMe3)Cl (5e). The preparation of complex 5e is identical to that of 4a. Complex 2e (0.250 g, 0.493 mmol), Me3SiC=CSiMe3 (0.222 g, 1.303 mmol) and excess Na/Hg amalgam (0.120 g Na, 5.22 mmol; 12.0 g Hg) gave red crystalline 5e (0.197 g, 0.327 mmol, 66 %). 'H NMR 8 6.96 (t, 1H, py), 6.44 (d, 2H, py), 4.49 (s, 4H, NC//2), 3.86 (sept, 2H, NC//Me2), 1.09 (d, 6H, NCHM<?2), 0.70 (s, 9H, SiMe3), 0.66 (d, 6H, NCHMe2), -0.096 (s, 9H, SiMe3). 13C{'H} NMR 8 221.73, 215.06, 165.13, 137.53, 116.90, 58.28, 42.47, 19.64, 17.50, 1.69, 1.16. (iPAP)Ta{C4a-ot'(SiMe3)2H2}(CCSiMe3) (6e). To a diethylether solution (50 mL) of complex 2e (0.250 g, 0.493 mmol) was added 3 equivalents of HC=CSiMe3 (0.150 g, 1.527 mmol) and an excess of Na/Hg amalgam (0.113 g Na, 4.93 mmol; 11.3 g Hg). The solution was sdred for 12 hours. The black solution was filtered and the solvent removed in vacuo. The resulting solid was dissolved in a minimum amount of hexanes and cooled to -30° for 12 hours. Bright red crystalline 6e was isolated by filtration and dried under vaccum (0.217 g, 0.325 mmol, 66 %). 'H NMR 8 8.60 (d, 1H, p-C#), 7.49 (d, 1H, p-C//), 7.08 (t, 1H, py), 6.65 (d, 2H, py), 4.60 (AB quartet, 2JHH = 20.1 Hz, 4H, NC//2), 2.52 (sept, 2H, NC//Me2), 0.75 (d, 6H, NCHMe2), 0.58 (d, 6H, NCHMe2), 0.55 (s, 9H, SiMe,), 0.28 (s, 9H, SiMe3), 0.21 (s, 9H, SiMe3). 13C{'H} NMR 8 218.49, 204.50, 199.63, 167.27, 148.87, 145.63, 137.39, 128.87, 116.98, 59.46, 44.89, 21.42, 19.38, 2.54, 1.13, -0.09. (BDPP)Ta(r)2-EtC=CEt)Cl (7a). The preparation of compound 7a is identical to that for 4a. Compound 2a (0.500 g, 0.673 mmol), 3-hexyne (0.200 g, 2.43 mmol) and excess Na/Hg amalgam (0.186 g Na, 8.09 mmol; 18.6 g Hg) gave yellow crystalline 7a (0.417 g, 0.553 mmol, 82%). 1H NMR 8 7.19, (t, 2H, Ar), 7.11 (d, 4H, Ar), 6.84 (t, 1H, py), 6.39 (d, 2H, py), 5.11 (AB quartet, 2Jm = 20.1 Hz, 4H, NC//2), 3.79 (sept, 2H, C#Me2), 3.13 (sept, 2H, C#Me2), 2.59 (q, 4H, =CCH2), 1.46 (d, 6H, CHMe2), 1.32 (d, 6H, CUMe2), 1.21 (d, 6H, References start on page 238 230 CUMe2), 1.02 (d, 6H, CHMe2), 0.94 (t, 6H, CH2C/73). 13C{1H} NMR 8 237.81 (C=C), 160.76, 154.34, 145.17, 142.88, 138.41, 125.57, 124.35, 123.59, 117.01, 70.94, 30.56, 28.53, 27.94, 26.69, 25.76, 24.61, 23.77, 13.03. Anal. Calcd for C37H51N3TaCl: C, 58.92; H, 6.82; N, 5.57. Found: C, 58.97; H, 6.70; N, 5.38. (BDMP)Ta(r|2-EtC=CEt)Cl (7b). The preparation of compound 7b is identical to that of 4a. Compound 2b (0.250 g, .396 mmol), 3-hexyne (0.081 g, 0.991 mmol) and excess Na/Hg amalgam (0.137 g Na, 5.95 mmol; 13.7g Hg) gave yellow crystalline 7b (0.187 g, .276 mmol, 70%). 'H NMR 8 7.00 (d, 4H, Ar), 6.88 (t, 2H, Ar), 6.78 (t, IH, py), 6.41 (d, 2H, py), 4.67 (AB quartet, ^ = 20.2, 4H, NC/72), 2.70 (q, 4H, =CCH2), 2.56 (s, 6H, CH3), 2.11 (s, 6H, C//3), 0.95 (t, 6H, CH2C/Y3). 13C{'H} NMR 8 238.20 (C=C), 160.70, 155.86, 138.14, 135.03, 133.08, 128.64, 124.78, 117.28, 67.22, 30.79, 19.65, 18.97, 13.52. (BDPP)Ta(r)2-PhC=CPh)Cl (8a). The preparation of compound 8a is identical to that for 4a. Compound 2a (1.001 g, 1.346 mmol), diphenylacetylene (0.288 g, 1.62 mmol) and excess Na/Hg amalgam (0.619 g Na, 26.9 mmol; 61.9 g Hg) gave yellow crystalline 8a (0.567 g, 0.667 mmol, 51%). IH NMR 8 7.15-6.95 (m, 17H, Ar and Ph), 6.48 (d, 2H, py), 5.14 (AB quartet, 2JHH = 19.5 Hz, 4H, NC/72), 4.02 (sept, 2H, C/7Me2), 3.30 (sept, 2H, C//Me2), 1.30 (d, 6H, CHMe2), 1.08 (d, 12H, CHMe2), 1.04 (d, 6H, CUMe2). 13C{lH} NMR 8 228.20 (C=C), 159.94, 152.52, 147.23, 145.25, 144.13, 138.67, 126.96, 126.17, 124.55, 124.03, 117.37, 70.90, 28.85, 28.59, 27.56, 25.93, 24.33, 23.95. Anal. Calcd for C45H51N3TaCl: C, 63.56; H, 6.05; N, 4.94. Found: C, 63.21; H, 6.07; N, 4.42. (BDPP)Ta(r}2-PhC=CH)CI (9a). The preparation of compound 9a is identical to that for 4a. Compound 2a (0.250 g, 0.336 mmol), phenylacetylene (0.103 g, 1.01 mmol) and excess Na/Hg amalgam (0.230 g Na, 10.0 mmol; 23.0 g Hg) gave ivory crystalline 9a (0.207 g, 0.267 mmol, 79%). IH NMR 8 11.91 (s, IH, C=CH) 7.20-6.90 (m, Ar and Ph), 6.83 (t, IH, py), 6.36 (d, 2H, py), 5.08 (AB quartet, 21^ = 20.3 Hz, 4H, NC/Y2), 3.82 (sept, 2H, C/YMe2), 3.43 (sept, 2H, C/7Me2), 1.31 (d, 6H, CHMe2), 1.26 (d, 6H, CHMe2), 1.20 (d, 6H, CHMe2), References start on page 238 231 1.08 (d, 6H, CHMe2). 13C{1H} NMR 5 236.45 (PhC=C), 225.81(CsCH), 160.65, 152.78, 146.77, 145.38, 142.25, 138.68, 126.86, 125.94, 124.35, 123.69, 117.30, 70.60, 28.54, 27.96, 26.47, 26.27, 24.70, 23.99. (BDPP)Ta(r)2-SiMe3C=CH)Cl (10a). The preparation of compound 10a is identical to that of 4a. Compound 2a (0.250 g, 0.336 mmol), phenylacetylene (0.103 g, 1.01 mmol) and excess Na/Hg amalgam (0.230 g Na, 10.0 mmol; 23.0 g Hg) gave yellow crystalline 10a (0.207 g, 0.267 mmol, 79%). 'H NMR 5 13.15 (s, 1H, //C=C), 7.25-7.15 (m, 6H, Ar), 6.86 (t, 1H, py), 6.38 (d, 2H, py), 5.06 (AB quartet, 2JHH = 20.2 Hz, 4H, NC//2), 3.74 (sept, 2H, C//Me2), 3.33 (sept, 2H, C//Me2), 1.51 (d, 6H, CHMe2), 1.33 (d, 6H, CUMe2), 1.26 (d, 6H, CHMe2), 1.07 (d, 6H, CUMe2), 0.09 (s, 9H, SiMe}). 13C{'H} 8 245.60 (C^CPh), 242.27 (C^CH), 52.80, 145.19, 138.59, 126.06, 124.41, 123.95, 117.17, 70.87, 28.46, 27.94, 26.26, 25.86, 25.17, 23.44, -0.02. (BDPP)Ta(r|2-PrC=CPr)Me (12a). To a diethylether (25 mL) solution of compound 4a (0.600 g, 0.767 mmol) was added 1.2 equivalents of MeMgBr (0.38 mL, 2.4 M, 0.91 mmol) at -78°C. The yellow solution was warmed to 25°C and stirred for 12h. The solvent was removed in vacuo. The resulting solid was extracted with toluene (3 x 10 mL) and filtered through Celite to give a bright yellow solution. The solvent was removed in vacuo, the solid dissolved in a minimum amount of diethylether and cooled to -30°C for 12h. Yellow crystalline 12a was isolated by filtration and dried under vacuum (0.531 g, 0.697 mmol, 91%). 'H NMR 8 7.22-7.10 (m, 6H, Ar), 6.88 (t, 1H, py), 6.45 (d, 2H, py), 5.05 (AB quartet, 2jm = 20.5 Hz, 4H, NCff2), 3.60 (sept, 2H, C//Me2), 3.15 (sept, 2H, C//Me2), 2.46 (m, 4H, =CCH2), 1.42 (d, 6H, CHMe2), 1.34 (m, 4H, C//2CH3), 1.33 (d, 6H, CHMe2), 1.21 (d, 6H, CHMe2), 1.05 (d, 6H, CUMe2), 0.86 (t, 6H, CH2C//3), 0.44 (s, 3H, Me). 13C{1H} NMR 8 237.45 (C=C), 161.93, 155.12, 144.61, 143.12, 138.05, 124.84, 124.02, 123.61, 116.98, 70.69, 39.06 (Ta-CH3), 37.94, 28.78, 27.75, 26.49, 25.80, 24.56, 23.84, 22.10, 16.63. Anal. Calcd for C40H58N3Ta: C, 63.06; H, 7.67; N, 5.52. Found: C, 63.02; H, 7.79; N, 6.38. References start on page 238 232 [(BDPP)Ta(C4Pr4)]+[MeB(C6F5)3] (13a). To a toluene (5 mL) solution of compound 12a (0.050 g, 0.066 mmol) was added 1 equivalent of B(C6F5)3 (0.034 g, 0.066 mmol) and excess of 4-octyne (0.050 g, 0.580 mmol). The yellow solution was stirred for 12 hours during which a dark orange oil separated from the solution. The mother liquor was decanted off and the oil washed with 3x5 mL of cold pentane. Residual solvent was removed in vacuo to afford compound 13a as a dark orange oily liquid (0.073 g, 0.053 mmol, 80 %). 'H NMR (CD2C12) 8 8.25 (t, IH, py), 7.62 (d, 2H, py), 7.40-7.30 (m, 6H, Ar), 5.74 (s, 4H, NC/72), 3.11 (s, 4H, C/7Me2), 3.03 (m, 4H, =CH2), 2.69 (m, 4H, =CH2), 1.40 (d, 12H, CHMe2), 1.30 (d, 12H, CHMe2), 1.07 (br m, 8H, C/72CH3), 0.87 (t, 12H, CH2C//3), 0.58 (q, 3H, BC/73). (BDPP)Ta(r|2-PrOCPr)(C=CPh) (14a). To a diethylether (25 mL) solution of compound 4a (0.500 g, 0.634 mmol) was added 1.1 equivalents of PhCE=CLi (0.076 g, 0.703 mmol) at -78°C. The yellow solution was warmed to 25°C and stirred for 12h. The solvent was removed in vacuo. The resulting solid was extracted with toluene (3 x 10 mL) and filtered through Celite to give a bright yellow solution. The solvent was removed in vacuo, the solid dissolved in a minimum amount of pentane and cooled to -30°C for 12h. Yellow crystalline 14a was isolated by filtration and dried under vacuum (0.406 g, 0.479 mmol, 76%). IH NMR 8 7.59 (m, 2H, Ph), 7.22-7.10 (m, 7H, Ar and Ph), 7.01 (m, 2H, Ph), 6.80 (t, IH, py), 6.38 (d, 2H, py), 5.08 (AB quartet, 2Jm = 20.2 Hz, 4H, NC/Y2), 4.10 (sept, 2H, C/YMe2), 3.39 (sept, 2H, C//Me2), 2.81 (m, 4H, =CCH2), 1.53 (d, 6H, CHMe2), 1.39 (d, 6H, CHA/e2), 1.36 (d, 6H, CHMe2), 1.22 (m, 4H, C//2CH3), 1.10 (d, 6H, CHMe2), 0.87 (t, 6H, CH2C/Y3). 13C{lH} NMR 8 233.64 (PrC^CPr), 161.41, 153.22, 149.40, 145.21, 143.08, 138.16, 130.97, 127.12, 126.48, 126.23, 125.33, 124.32, 123.35, 117.05, 70.99, 40.96, 28.86, 27.84, 27.09, 25.93, 24.94, 24.10, 21.95, 15.52. (BDPP)Ta(Ti2-PrCHCPr)(C=C-o-Me3SiC6H4) (15a). The preparation of complex 15a is identical to that of complex 14a. Complex 4a (0.100 g, 0.128 mmol) and LK>C-o-References start on page 238 233 Me3SiC6H4 (0.023 g, 0.128 mmol) yielded orange crystalline 15a (0.087 g, 0.095 mmol, 74 %). 1H NMR 8 7.83 (d, 1H, Ph), 7.40 (d, 1H, Ph), 7.20-6.90 (m, 9H, Ar, py and Ph), 6.54 (d, 2H, py), 5.12 (AB quartet, 2Jm = 20.4 Hz, 4H, NC//2), 3.99 (sept, 2H, C#Me2), 3.43 (sept, 2H, C//Me2), 2.87 (m, 4H, C//2CH2Me), 1.43 (d, 6H, CHMe2), 1.37 (d, 6H, CUMe2), 1.35 (m, 4H, CH2Ctf2Me), 1.30 (d, 6H, CHMe2), 1.10 (d, 6H, CHMe2), 0.91 (t, 6H, CH2CH2Me), 0.21 (s, 9H, SiMe3). 13C pH} NMR 8 233.304 (PrC=CPr), 161.67, 153.07, 152.80, 145.27, 142.98, 138.25, 133.99, 133.54, 132.40, 129.22, 128.88, 126.26, 125.30, 124.29, 123.29, 117.20, 70.89, 40.83, 28.85, 27.78, 26.95, 25.96, 24.77, 24.06, 21.95, 15.50, -1.00. Anal. Calcd for C50H6gN3SiTa: C, 65.27; H, 7.45; N, 4.57. Found: C, 65.48; H, 7.59; N, 4.80. (BDPP)Ta(r]2-PrC=CPr)(C=CBu) (16a). The preparation of compound 16a is identical to that of complex 14a. Complex 4a (0.100 g, 0.128 mmol) and LiC=CBu (0.012 g, 0.128 mmol) yielded orange crystalline 16a (0.077 g, 0.093 mmol, 73 %). 1H NMR 8 7.24 (t, 2H, Ar), 7.14 (d, 4H, Ar), 6.85 (t, 1H, py), 6.41 (d, 2H, py), 5.09 (AB quartet, 2^ = 20.1 Hz, 4H, NC//2), 4.05 (sept, 2H, C//Me2), 3.32 (sept, 2H, C//Me2), 2.67 (m, 4H, C//2CH2Me), 2.22 (t, 2H, TaC=CCH2), 1.52 (d, 6H, CHM*2), 1.44 (d, 6H, CWMe2\ 1.40 (m, 8H, CH2 of octyne and butylacetylide), 1.31 (d, 6H, CHM<?2), 1.08 (d, 6H, CHM<?2), 0.88 (t, 6H, CH2CH2M«?), 0.87 (t, 3H, CH2CH2CH2Me). 13C{1H} NMR 8 235.46 (PrC=CPr), 161.46, 153.90, 145.11, 143.04, 139.10, 137.98, 125.50, 125.08, 124.16, 123.33, 116.88, 70.78, 40.50, 32.09, 28.70, 27.64, 27.02, 25.79, 24.88, 23.95, 22.19, 22.04, 21.36, 15.53, 13.91. (BDPP)Ta(T)2-PrC=CPr)(C=CSiMe3) (17a). The preparation of compound 17a is identical to that of 14a. Complex 4a (0.100 g, 0.128 mmol) and LiC^CSiMe3 (0.013 g, 0.128 mmol) yielded yellow crystalline 17a (0.102 g, 0.121 mmol, 95 %). 1H NMR 6 7.19 (t, 2H, Ar), 7.15 (d, 4H, Ar), 6.77 (t, 1H, py), 6.34 (d, 2H, py), 5.00 (AB quartet, 2JHH = 20.2 Hz, 4H, NCH2), 4.01 (sept, 2H, C//Me2), 3.35 (sept, 2H, C//Me2), 2.77 (m, 4H, C//2CH2Me), 1.51 (d, 6H, CHMe2), I A3 (d, 6H, CHMe2), 1.32 (d, 6H, CHMe2), 1.19 (m, 4H, CH2C//2Me), 1.06 (d, 6H, CHMe2), 0.85 (t, 6H, CH2CH2Me), 0.26 (s, 9H, SiMe3). 13C {1H} References start on page 238 234 NMR 8 232.68 (PrC=CPr), 169.14, 161.22, 153.05, 145.02, 143.08, 138.15, 130.89, 125.32, 124.33, 123.31, 117.04, 70.91, 40.89, 28.85, 27.52, 27.10, 25.88, 25.07, 24.11, 21.86, 15.47, 1.21. (BDPP)Ta{PhC=CHCPr=CPr(ri2-C=CPh)} (18a). To a toluene solution (5 mL) of compound 14a (0.100 g, 0.118 mmol) in a glass pressure vessel was added 1.5 equivalents of phenylacetylene (0.018 g, 0.177 mmol) at 25°C. The yellow solution was stirred at 110°C for 12 hours. The solvent was removed in vacuo. The resulting orange solid was dissolved in a minimum amount of diethyl ether and cooled to -30°C for 12 hours. Orange crystalline 18a was isolated by filtration and dried under vacuum (0.108 g, 0.114 mmol, 97%). IH NMR 8 7.19-7.10 (m, 6H, Ar), 7.05 (s, IH, PhC=C#), 7.04-6.98 (m, 4H, Ph), 6.90 (t, 2H, Ph), 6.82 (tt, IH, Ph), 6.76 (t, IH, py), 6.74 (tt, IH, Ph), 6.25 (d, 2H, py), 5.60 (dd, 2H, Ph), 4.87 (AB quartet, 2Jm = 20.1 Hz, 4H, NC//2), 4.10 (sept, 2H, C/7Me2), 3.36 (sept, 2H, C//Me2), 2.24 (m, 4H, =C/72), 1.62 (m, 2H, =CH2), 1.43 (d, 6H, CHMe2), 1.35 (d, 6H, CHMe2), 1.22 (m, 2H, C//2CH3), 1.08 (d, 6H, CHMe2), 1.01 (d, 6H, CHMe2), 0.93 (t, 3H, CH2C//3), 0.51 (t, 3H, CH2C//3). 13C{1H} NMR 8 220.26 (PhOCH), 189.90 (PhCsCH), 160.83, 158.63, 154.09, 151.86, 147.39, 145.14, 144.72, 142.08, 137.95, 128.89, 127.16, 126.73, 125.69, 125.47, 124.08, 123.98, 123.87, 123.34, 116.85, 71.21, 37.31, 34.30, 29.03, 27.95, 27.83, 25.92, 24.88, 24.58, 23.52, 23.30, 15.24, 14.68. Anal. Calcd for C55H66N3Ta: C, 69.53; H, 7.00; N, 4.42; Found: C, 69.95; H, 7.41; N, 4.71. (BDPP)Ta{BuC=CHCPr=CPr(r|2-CHCBu)} (19a). The preparation of compound 19a is identical to that of compound 18a. Complex 16a (0.100 g, 0.098 mmol) and HC^CBu (0.010 g, 0.122 mmol) yielded red crystalline 19a (0.086 g, 0.078 mmol, 80 %). IH NMR 8 7.17-7.05 (m, 6H, Ar), 6.91 (t, IH, py), 6.85 (s, IH, BuC=C//), 6.46 (d, 2H, py), 4.98 (AB quartet, 2jm = 21.0 Hz, NC/72), 3.66 (sept, 2H, C/7Me2), 3.59 (sept, 2H, CHMe2), 2.77 (m, 2H, C/Y2CH2Me), 2.48 (m, 2H, C/72CH2Me), 2.34 (t, 2H, C/V2CH2CH2Me), 2.23 (br m, 2H, C//2CH2CH2Me), 1.63 (m, 4H, CH2C/Y2CH2Me), 1.42 (d, 6H, CHMe2), 1.33 (d, 6H, References start on page 238 235 CUMe2), 1.26 (d, 6H, CHMe2), 1.12 (d, 6H, CHMe2), 1.30 (buried, 8H, CH2 Pr and Bu), 1,00, 0.86, 0.82 and 0.71 (t, 3H each, CH^e Pr and Bu). 13C{1H} NMR 8 237.52, 236.28, 195.53, 162.11, 153.35, 145.00, 144.20, 141.34, 140.95, 138.11, 137.01, 128.09, 124.27, 123.25, 116.19, 71.52, 43.49, 39.59, 37.17, 35.27, 34.96, 31.15, 28.84, 27.29, 26.99, 25.99, 25.33, 24.50, 24.42, 23.76, 23.65, 21.99, 15.23, 14.81, 14.58, 14.10. (BDPP)Ta{PhC=CHCPr=CPr(r|2-C=CBu)} (20a). The synthesis of compound 20a is identical to that of 18a. Complex 16a (0.100 g, 0.098 mmol) and HC^CPh (0.015 g, 0.147 mmol) yielded red crystalline 20a (0.076 g, 0.068 mmol, 69 %). 1H NMR 8 7.30-7.10 and 6.90-6.70 (m, 12H, Ar, Ph and py), 6.14 (d, 2H, Ph), 5.38 (AB quartet, 2JHH = 19.9 Hz, 4H, NC//2), 4.16 (sept, 2H, C//Me2), 3.39 (m, 2H, C//2CH2CH2Me), 3.11 (s, 1H, PhC=Ctf), 3.05 (sept, 2H, C#Me2), 2.30 (m, 2H, Ctt2CH2Me), 1.65 (m, 4H, CH2 Pr or Bu), 1.60 (m, 4H, CH2 ProrBu), 1.49 (d, 6H, CHMe2), 1.43 (d, 6H, CHMe2), 1.35 (d, 6H, CHMe2), 1.22 (m, 5H, CH2 and C//„ Pr or Bu), 1.02 (d, 6H, CHMe2), 0.97 (t, 3H, C//3 Pr or Bu), 0.81 (t, 3H, CHi Pr or Bu). 13C{1H} NMR 8 221.17, 204.45, 163.86, 162.56, 156.19, 149.68, 148.58, 148.10, 143.55, 138.81, 127.03, 126.20, 125.16, 123.46, 123.27, 117.30, 70.91, 48.59, 34.79, 28.77, 28.65, 28.25, 27.55, 24.31, 23.44, 23.13, 22.84, 15.88, 15.40. (BDPP)Ta{Me,SiC=CHCPr=CPr(r]2-C=SiMe3)} (21a). The synthesis of compound 21a is identical to that of 18a. Complex 17a (0.100 g, 0.096 mmol) and HC=CSiMe3 (0.015 g, 0.153 mmol) yielded red crystalline 21a (0.113 g, 0.088 mmol, 92 %). 1H NMR 8 7.10-6.90 (m, 7H, Ar and py), 6.54 (d, 1H, py), 6.49 (d, 1H, py), 5.17 (AB quartet, 2JHH = 19.4 Hz, 2H, NC//2), 4.93 (AB quartet, 2JHH = 20.4 Hz, 2H, NCH2), 4.08 (sept, 1H, C//Me2), 3.58 (sept, 1H, C//Me2), 3.08 (sept, 1H, C#Me2), 2.96 (m, 1H, C#2CH2Me), 2.90 (s, 1H, C//=CSiMe3), 2.67 (m, 2H, C#Me2 and C//2CH2Me), 2.36 (m, 1H, C#2CH2Me), 2.24 (m, 1H, C//2CH2Me), 1.84 (m, 1H, CH2C//2Me), 1.64 (m, 1H, CH2C//2Me), 1.57 (d, 3H, CUMe2), 1.51 (d, 3H, CHMe2), 1.27 (d, 3H, CHMe2), 1.26 (d, 3H, CHMe2), 1.20 (m, 2H, CU2CH2Me), 1.10 (d, 3H, CHMe2), 1.08 (d, 3H, CHMe2), 1.08 (buried, 3H, References start on page 238 236 CH2CH2Me), 1.06 (d, 3H, CHMe2), 0.92 (d, 3H, CHMe2), 0.74 (t, 3H, CH2CH2Me), 0.28 (s, 9H, SiMe3),-0.19 (s, 9H, SiMe3). 13C{IH} NMR 5 233.53, 190.05, 169.56, 167.86, 163.49, 162.93, 155.43, 154.54, 145.76, 144.21, 143.31, 142.58, 138.57, 132.39, 124.51, 123.93, 123.84, 123.51, 123.37, 122.32, 117.11, 116.88, 68.81, 68.59, 55.34, 33.06, 29.98, 29.03, 27.48, 27.36, 27.28, 26.10, 25.84, 25.12, 24.86, 24.25, 24.17, 24.00, 22.57, 14.83, 14.69, 3.95, -0.51. (BDPP)Ta{Me3SiC=CHCPr=CPr(ri2-C=SiMe3)} (22a). The synthesis of compound 22a is identical to that of 18a. Complex 17a (0.100 g, 0.096 mmol) and HC=CPh (0.015 g, 0.147 mmol) yielded red crystalline 22a (0.097 g, 0.076 mmol, 79 %). IH NMR 5 7.50-6.50 (m, 10H, Ar, Ph and py), 6.37 (d, IH, py), 6.35 (d, IH, py), 6.21 (d, 2H, Ph), 5.01 (AB quartet, 2jm = 20.1 Hz, 2H, NC/Y2), 4.97 (AB quartet, 2JHH = 20.1 Hz, 2H, NCtf2), 4.10 (sept, IH, C/YMe2), 3.77 (br m, 4H, C/7Me2 and PhC=C//), 2.55 (m, IH, C/72CH2Me), 2.41 (m, 3H, C#2CH2Me), 1.78 (m, 4H, CH2C/72Me), 1.60 (d, 3H, CHMe2), 1.53 (d, 3H, CHMe2), 1.38 (d, 3H, CUMe2), 1.31 (d, 3H, CHMe2), 1.24 (d, 3H, CHM<?2), 1.00-0.84 ( m, 15H, CH2CH2M<? and CHMe2), -0.29 (s, 9H, SiMe3). 13C{1H} NMR 6 240.72, 234.10, 192.94, 161.07, 160.43, 156.69, 156.16, 154.01, 153.35, 153.02, 146.04, 144.64, 144.21, 144.05, 143.59, 140.09, 139.37, 138.96, 138.00, 136.14, 131.14, 127.11, 126.80, 126.72, 126.14, 125.86, 125.43, 124.84, 124.46, 124.64, 124.11, 123.90, 123.88, 116.70, 116.65, 71.76, 71.44, 38.95, 31.13, 30.33, 29.93, 28.05, 27.20, 26.94, 26.45, 26.29, 25.77, 25.39, 24.60, 24.23, 24.14, 22.86, 22.78, 15.34, 15.10, 0.54. X-ray Crystallographic Analysis (4a). A suitable crystal of 4a (dimension 0.45 x 0.23 x 0.20 mm) was grown from a saturated ether solution at -30°C. Data were collected on a Siemens P4 diffractometer with the XSCANS software package^. The cell constants were obtained by centering 25 reflections (18.0 < 20 <24.7°). The Laue symmetry 1 was determined by merging symmetry equivalent positions. The data were collected in the range of 0 = 1.9-23° (-l<h<10, -1 l<k< 12, -19<1<19) in u) mode at variable scan speeds (2-20 deg/min). Four standard reflections monitored at the end of every 297 reflections collected showed no decay of the crystal. References start on page 238 237 The data processing, solution and refinement were done using SHELXTL-PC programs51. The final refinements were performed using SHELXL-93 software programs^. An empirical absorption correction was applied to the data using the routine 'XEMP' on the basis of the \|/ scans of 11 reflections with 29 ranging from 8.5 to 25.9° (f! = 2.995 mm"1). The methyl carbon atoms attached to C(29) were found to be disordered. Three orientation (0.33/0.33/0.33) of C(30) and C(31) were located in the final difference Fourier methods. Isotropic thermal parameters were refined for these disordered carbon atoms. Anisotropic thermal parameters were refined for all non-hydrogen atoms. No attempt was made to locate the hydrogen atoms, however, they were placed in calculated positions. The C-C distances in the isopropyl groups were restrained to be equal using the option SADI. In the final difference Fourier synthesis the electron density fluctuates in the range 0.788 to -0.677 e A"3. X-ray Crystallographic Analysis (18a). A suitable crystal of 18a (dimension 0.10 x 0.1 x 0.1 mm) was grown from a saturated ether solution at -30°C. Data were collected on a Siemens Smart system CCD diffractometer. The data were collected in the range of 9 = 1.47-21° (-17<h<17, -ll<k<23, -28<1<27). Unit-cell parameters were calculated from reflections obtained from 60 data frames collected at different sections of the Ewald sphere. The systematic absences in the diffraction data and the determined unit-cell parameters were uniquely consistent for the reported space group. A trial application of semi-empirical absorption correction based on redundant data at varying effective azimuthal angles yielded Tmax/Tniin at unity and was ignored. A molecule of cocrystallized n-hexane solvent was located at the inversion centre. All C-C distances in the solvent molecule were constrained to be equal. All non-hydrogen atoms were refined with anisotropic displacement coefficients. All hydrogen atoms were treated as idealized contributions. The structure was solved by direct methods, completed by subsequent Fourier syntheses and refined with full-matrix least-squares methods. All scattering factors and anomalous dispersion coefficients are contained in the SHELXTL 5.03 program library^9. m me final difference Fourier synthesis the electron density fluctuates in the range 0.667 to -0.634 e A"3. References start on page 238 238 5 References ;i) Bradley, D. C; Gitlitz, M. H. J. Chem. Soc. (A) 1969, 980. 2) Bradley, D. C; Thomas, I. M. Can. J. Chem. 1962, 40, 1355. 3) Bradley, D. C; Thomas, I. M. Chemical Society London. Proceedings 1959, 225. 4) Burger, H. Monatsh. 1964, 95, 671. ;5) Suh, S.; Hoffman, D. M. Inorg. Chem. 1996, 35, 5015. ;6) Bradley, D. C; Gitlitz, M. H. J. Chem. Soc. (A) 1969, 1894. 7) Fuggle, J. C.; Sharp, D. W. A.; Winfield, J. M. J. Chem. Soc, Dalton Trans. 1972, 1766. ;8) Masuda, T.; Isobe, E.; Higashimura, T; Takada, K. J. Am. Chem. Soc. 1983, 105, 7473. ;9) Masuda, T.; Niki, A.; Isobe, E.; Higashimura, T. Macromolecules 1985,18, 2109. ;i0) Cotton, F. A.; Hall, W. T.; Cann, K. J.; Karol, F. J. Macromolecules 1981, 14, 233. ;il) Bruck, M. A.; Copenhaver, A. S.; Wigley, D. E. J. Am. Chem. Soc. 1987, 109, 6525. ;i2) Clarke, T. C. J. Am, Chem. Soc. 1983, 705, 7797. ;i3) Clarke, T. C; Yannoni, Y. S.; Katz, T. J. J. Am, Chem. Soc. 1983, 705, 7787. T4) Katz, T. J.; Hacker, S. M.; Kendrick, R. D.; Yannoni, C. S. J. Am, Chem. Soc. 1985, 107, 2182. ;i5) Katz, T. J.; Ho, T. H.; Shih, N.-Y.; Ying, Y.-C; Stuart, V. I. W. J. Am. Chem. Soc. 1984, 706, 2659. (16) Etienne, M.; Mathieu, R.; Donnadieu, B. J. Am. Chem. Soc. 1997, 779, 3218. (17) Chao, Y.-W.; Wexler, P. A.; Wigley, D. E. Inorg. Chem. 1989, 28, 3860. (18) Green, M. L. H.; Jousseaume, B. J. Organomet. Chem. 1980,193, 339. (19) Gibson, V. C; Parkin, G.; Bercaw, J. Organometallics 1991, 70, 220. (20) Labinger, J. A.; Schwartz, J.; Townsend, T. M. J. Am. Chem. Soc. 1974, 96, 4009. (21) Antinolo, A.; Fajardo, M.; Otero, A.; Royo, P. J. Organomet. Chem, 1983, 246, 269. (22) Herberich, G. E.; Savvopoulos, I. J. Organomet. Chem, 1989, 365, 345. (23) Herberich, G. E.; Hessner, B.; Mayer, H. J. Organomet. Chem. 1986, 314, 123. References start on page 238 239 (24) Herberich, G. E.; Hoeveler, U. E. M.; Savvopoulos, I. J. Organomet. Chem. 1990, 399, 35. (25) Herberich, G. E.; Mayer, H. Organometallics 1990, 9, 2655. (26) Yasuda, H.; Yamamoto, H.; Takashi, A.; Nakamura, A.; Chen, J.; Kai, Y.; Kasai, N. Organometallics 1991,10, 4058. (27) Hirpo, W.; Curtis, M. D. Organometallics 1994, 13, 2706. (28) Smith, G.; Schrock, R. R.; Churchill, M. R.; Youngs, W. J. Inorg. Chem. 1981, 20, 387. (29) Curtis, M. D.; Real, J.; Hirpo, W.; Butler, W. D. Organometallics 1990, 9, 66. (30) Strickler, J. R.; Bruck, M. A.; Wigley, D. E. J. Am. Chem. Soc. 1990, 112, 2814. (31) Strickler, J. R.; Wexler, P. A.; Wigley, D. E. Organometallics 1991, 10, 118. (32) Strickler, J. R.; Wexler, P. A.; Wigley, D. E. Organometallics 1988, 2067. (33) Schrock, R. R. Acc. Chem. Res. 1979,12, 98. (34) Wood, C. D.; McLain, S. J.; Schrock, R. R. J. Am. Chem. Soc. 1979,101, 3210. (35) Rupprecht, G. A.; Messerle, L. W.; Fellmann, J. D.; Schrock, R. R. J. Am. Chem. Soc. 1980,102, 6236. (36) Messerle, L. W.; Jennische, P.; Schrock, R. R.; Stucky, G. J. Am. Chem, Soc. 1980, 102, 6744. (37) Schrock, R. R.; Messerle, L. W.; Wood, C. D.; Guggenberger, J. L. J. Am. Chem. Soc. 1978,100, 3793. (38) Lockwood, M. A.; Clark, J. R.; Bernardeta, P. C; Rothwell, I. P. J. Chem. Soc, Chem. Commun. 1996, 1973. (39) Mowat, W.; Wilkinson, G. J. Chem. Soc, Dalton Trans. 1972, 1120. (40) Malatesta, V.; Ingold, K. U.; Schrock, R. R. J. Organomet. Chem, 1978, 152, C53. (41) Wallace, K. C; Liu, A. H.; Dewan, J. C; Schrock, R. R. J. Am. Chem. Soc. 1988, 110, 4964. (42) Schrock, R. R.; Fellmann, J. D. J. Am. Chem. Soc. 1978,100, 3359. References start on page 238 240 (43) Bradley, D. C; Ghotra, J. S.; Hart, H. A. J. Chem. Soc, Chem. Commun. 1972, 349. (44) Templeton, J. L.; Ward, B. C. J. Am. Chem. Soc 1980,102, 3288. (45) Theopold, K. H.; Holmes, S. J.; Schrock, R. R. Angew. Chem., Int. Ed. Engl. 1983, 22, 1010. (46) Belmonte, P. A.; Cloke, F. G. N.; Theopold, K. H.; Schrock, R. R. Inorg. Chem. 1984, 23, 2365. (47) Cotton, F. A.; Hall, W. T. Inorg. Chem. 1980,19, 2352. (48) Morrison, R. T.; Boyd, R. N., Organic Chemistry; 5th ed.; Morrison, R. T.; Boyd, R. N., Ed.; Allyn & Bacon, Inc.: Boston, 1987, pp 427. (49) Massey, A. G.; Park, A. J. J. Organomet. Chem. 1964, 2, 245. (50) . (51) Cotter, W. D.; Bercaw, J. E. J. Organomet. Chem. 1991, 417, CI. (52) Eisch, J. J.; Piotrowski, A. M.; Brownstein, S. K.; Gahe, E. J.; Lee, F. L. J. Am. Chem. Soc. 1985, 107, 7219. (53) Jordan, R. F.; Lapointe, R. E.; Bradley, P. K.; Baezinger, N. Organometallics 1989, 8, 2892. (54) Horton, A. D.; Orpen, A. G. Organometallics 1991,10, 3910. (55) Masuda, T.; Hamano, T.; Tshuchihara, K.; Higashimura, T. Macromolecules 1990, 23(5), 1374. (56) XSCANS; Siemens Analytical X-Ray Instruments Inc.: Madison, 1990. (57) Sheldrick, G. M. SHELXTL-PC; V4.1 ed.; Sheldrick, G. M., Ed.; Siemens Analytical X-Ray Instruments Inc.: Madison, WI, U.S.A., 1990. (58) Sheldrick, G. M. SHELXL-93; Sheldrick, G. M., Ed.; Institute fuer Anorg. Chemie: Goettingen, Germany, 1993. (59) , "SHELXTL Version 5", Siemans Analytical X-ray Instruments Inc., Madison WI, 1994. References start on page 238 241 " Stupidity does not consist in being without ideas. Such stupidity would be the sweet, blissful stupidity of animals, mollusks and the gods. Human stupidity consists in having lots of ideas, but stupid ones. Stupid ideas, with banners, hymns, loudspeakers and even thanks and flame-throwers as their instruments of persuasion, constitute the refined and the only really terrifying form of stupidity." Henry De Montherlant 242 Chapter Four. Group 3 Metal Complexes 1 Introduction Ziegler was the first to report the polymerization of ethylene at ambient pressure using a TiCL/AlEtj catalyst system1'2. This system is, however, heterogeneous and the active species is believed to be a neutral Tira or a cationic Ti™ complex. The proposed mechanism involves the insertion of a C2H4 molecule into a metal-alkyl bond and requires a vacant coordination site (Scheme 4- 1). R. V CH2 i CoH 2n4 Empty coordination site R / H2C .** /CH2 i:—C H2 a \ • CH2 CH2 :Ti— CH2 -TL %CHC Scheme 4- 1. Cossee-Arlman Mechanism of Ziegler-Natta catalysis Long after this discovery, other groups used cyclopentadienyl-based systems such as Cp2TiPh2, Cp2ZrPh2 or Cp2ZrCl,3 as models for Ziegler-Natta catalysis. These systems are homogeneous and have comparable activities than the original heterogeneous catalysts. In homogeneous solutions, cations are postulated to be the catalytically active metal species. For References start on page 253 243 example, the base-stabilized complex Cp2ZrMe(THF)+ has been isolated and used for the polymerization of ethylene (Figure 4- 1)4-11 Figure 4- 1. Cationic Cp2MR In these polymerizations, an excess of an aluminum co-catalyst (500 to 10000 equiv), MAO (methylaluminoxane) is used. The co-catalyst is believed to play three roles. The first one is to act as an alkylating agent (Scheme 4- 2a). The second is to abstract one of the methyl groups to form in situ a cationic alkyl complex (Scheme 4- 2b). Finally, it is used to remove moisture from the system. a) Cp2TiCI2 + Cp2Ti \ Me Me b) Cp2Ti \ Me Me Cp2Ti \ Me Scheme 4- 2. Roles of MAO Other co-catalysts have since been developed. Boron-based co-catalysts such as B(C6F5)312 or (Ph3C)[B(C6F5)4]13 have been used in combination with transition metal complexes. These co-catalysts are however expensive to prepare. References start on page 253 244 The synthesis of olefin polymerization catalysts that do not require a co-catalyst showed growing interest. Complexes based on an (alkyl)metallocene complex containing a Scm, Y111 or a trivalent lanthanide center of the type Cp2MmR (Cp = r|5-C5H5, T|5-C5Me5; M = Sc14'17, Y15'18, Lal9, Lu20-25; R = halide, alkyl, H) act as single component catalysts for the polymerization of ethylene. These complexes are generally more difficult to prepare and to handle than the isostructural canonic or neutral group 4 complexes. Moreover, these systems do not polymerize a-olefins very efficiently and short chain oligomers (C<24) are obtained for the few systems that effect propene oligomerizadon 19. Complexes that contain a single Cp ligand where prepared in an attempt to generate a highly electrophilic and more open metal centre. With this in mind, the synthesis and catalytic activity of a scandium complex that contains a linked cyclopentadienyl-amide ligand (e.g., [(r)5-C5Me4)SiMe2(NCMe3)]MCl, M = Sc26) (Figure 4- 2) was reported. This well-characterized, single-component organoscandium system is capable of catalyzing the regioselective polymerization of a-olefins with degrees of polymerization as high as 70. Me,Si Figure 4- 2. Linked Cp-amide complex There are very few homoleptic amide complexes known for scandium and yttrium. The use of sterically demanding di(alkyl) or di(silyl) amides has allowed the isolation of some tris(amido)metal(III) species [e.g., M{N(SiMe3)2}3, M = Sc27"30, Y31,32; Y(N'Pr2)333]. These complexes are all monomeric in. solution with a three coordinate metal environment. X-ray diffraction studies on the Sc{N(SiMe3)2}3 0 confirm the three coordinate metal environment. References start on page 253 245 However, the metal atom resides just above the N3 plane. The deviation from planarity is attributed to rather ionic metal-nitrogen bonds, making the complex geometrically flexible. In contrast, the Ti111 complex Ti{N(SiMe3)2}328>34 has a planar molecular geometry in the solid state (by X-ray analysis). References start on page 253 246 2 Results and Discussion The reaction between YC13 and compound la {(BDPP)(SiMe3)2} (160 °C) did not proceed and only starting materials were isolated from the reaction mixture. In a similar way, no reaction was observed between YC13»3THF and compound lb at 160 °C. The lack of reactivity of YC13 may in part be due to its polymeric structure which prevents coordination of the ligand. On the other hand, the coordinated solvent molecules in YC13»3THF are not labile and may also preclude coordination of the solvent. The alkane elimination reaction between Y(CH2SiMe3)2»2THF and the diamine 2a {(BDPP)H2} affords complex 3 in good yield (eq. 1). The compound is highly soluble in hexanes and is difficult to separate from unreacted free ligand and other impurities present in the reaction mixture. Moreover, complex 3 is extremely air and moisture sensitive and special care must be taken to ensure the absence of water or oxygen. The room temperature 'H NMR spectrum of complex 3 confirms the proposed solvent adduct structure shown above. Another interesting feature is the very broad resonances observed for the ligand fragment. The -60°C 'H NMR spectrum displays a sharp AB quartet for the ligand methylene protons (NC//2) and two isopropyl methine resonances. The coalescence temperature (1) (3) References start on page 253 247 is approximately 15°C with an equilibrium constant K = 485 s'1. This is attributed to the weak coordination of the tetrahydrofiiran molecule (eq. 2). It is possible to exchange the THF molecule by recrystallization of complex 2 from diethyl ether. The room temperature 'H NMR spectrum of the Et20 complex 4 displays sharp resonances indicating that the Et,0 is strongly bounded to the yttrium centre. The AB quartet observed for the ligand methylene (NC//2) protons and the two isopropyl methine resonances are consistent with a complex with Cs geometry. The reaction between Y(CH2C6H4-o-NMe2)3 and compound la at room temperature does not result in the elimination of CH3C6H4-o-NMe2. Decomposition of the starting yttrium tri(alkyl) complexes is observed upon heating to 110 °C in Toluene-d8. This might be a result of the saturated coordination sphere of the starting yttrium complex. Pre-coordination of the ligand is precluded by the presence of the pending amino donors of the alkyl groups. The alkane elimination seems to be limited to alkyl compounds derived from stable coordinadvely unsaturated tris(alkyl)yttrium complexes. A more general pathway to the synthesis of yttrium alkyl complexes stabdized by the pyridine diamide ligand was sought. A different approach to the synthesis of complex 3 involves pre-coordination of the ligand to the metal halide complex. The high temperature reaction (150 °C, 1,2-dichlorobenzene) between compound la and YC13#3THF affords a white microcrystalline compound (2). Complex References start on page 253 248 2 is insoluble in all common non-protic organic solvent and could not be characterized by spectroscopic means. The !H NMR spectrum of the hydrolysis product from compound 2 indicated the presence of one THF molecule for each ligand molecule. The stoichiometry YC13»THF»(BDPP)H2 is advanced based on this result. The reaction between complex 2 and 3.3 equiv of ClMgCH2SiMe3 in THF yields the previously characterized mono(alkyl) complex 3 in good yield. The addition of 3 equiv of LiCH2SiMe3 to a suspension of complex 2 in hexanes affords a dark purple solution and small amounts of compound 3. The dark purple solution is similar to those obtained upon addition of n-BuLi to compound la and result from abstraction of the CH2N proton of the ligand. Similar results are obtained upon addition of Li(CH2C6H4-o-NMe2) or NaCp#DME. The addition of excess MeMgBr to a suspension of compound 2 in diethylether results in a rapid color change to light yellow. The reaction products are stable in coordinating solvents such as Etfi or THF but gas evolution (likely methane) is observed upon addition of toluene or benzene. Attempts to synthesis the Ph or CH2Ph derivatives from compound 3 and PhMgCl or PhCH2MgCl were unsuccessful. It is clear from these results that the pyridine diamide ligand bearing the 2,6-diisopropylphenyl substituents does not efficiently stabilize yttrium complexes. This can be interpreted as a consequence of the large covalent radius of yttrium (1.78 A)3^. From single crystal X-ray analysis (see previous chapters), the average distance between the amide groups is approximately 2.48 A {Figure 4- 3(1)}. A small metal such as titanium (cov. rad. 1.21 A)3^ is located in between the amides and is sterically protected {Figure 4- 3(11)}. The slighdy larger zirconium (cov. rad. 1.34 A)3^ also fits between the two amides but is pulled out slighdy resulting in a longer pyridine-nitrogen-metal bond (2.265 A compared to 2.178 A for Ti) {Figure 4- 3(111)}. For a large metal atom such as yttrium, the metal atom is too large to be located References start on page 253 249 between the amide groups. In order to remain within bonding distance to the pyridine nitrogen, the metal atom must slip out of the protective pocket {Figure 4- 3(IV)}. (I) (II) (III) (IV) Figure 4- 3. Size of the metal vs coordination geometry Attempts to synthesized the scandium complexes (BDPP)ScCH2SiMe3*L (L = THF, Et,0) were unsuccessful partly due to the lack of a suitable starting material. For example, the tris(alkyl) complex Sc(CH2SiMe3)3»2THF36 ,which is stable at temperatures below 0 °C, does not react with the diamine la at low temperature. Interestingly, the linked Cp-amine ligand {Cp(H)(CH2CH2NMe2)SiMe2NR(H)} reacts cleanly with Sc(CH2SiMe3)3«2THF37. In this case, as a result of its lower pit, (ca. 1638), the CpH reacts easily with the metal centre. In the pyridine diamine case, the high pit, (ca. 3838) of the amine groups render the alkane elimination more difficult and the scandium starting material decomposes when the reaction mixture is allowed to warm to room temperature. Similar results were obtained upon stirring the reaction mixture at 0°C for a prolonged period of time (18 hours). Moreover, the coordinated solvent molecules in ScCl3*3THF are not labile and the formation of ligand adducts as described earlier for yttrium was not possible. References start on page 253 250 3 Conclusions The reaction between Y(CH2SiMe3)3»2THF and (BDPP)(H2) affords the base adduct complex 3. Alternatively, complex 3 can be synthesized by pre-coordination of the ligand to form the ligand adduct 2 followed by alkylation using an excess of ClMgCH2SiMe3. The 'H NMR spectrum of complex 3 suggests rapid coordinadon-decoordination of the THF molecule. The THF molecule in complex 3 can be exchanged by crystallization in diethylether to form complex 4. In contrast to complex 3, the diethylether molecule in complex 4 is firmly bound to the yttrium centre. Attempts to generates other yttrium alkyl derivatives bearing the pyridine diamide ligand were unsuccessful. The large covalent radius of yttrium forces the metal centre to slip out of the protective pocket created by the substituted aryl groups of the ligand. As a result of the lack of a convenient starting material, the scandium complex (BDPP)ScCH2SiMe3«L (L = THF, Et^O) was not synthesized. References start on page 253 251 4 Experimental Details General details. See chapter one for general details. The ligands (BDPP)(H2) (la) and (BDPP)(SiMe3)2 (lb) were prepared as described in chapter one. The YC13 was purchased from Alfa and used as received. The YCls'STHF^, Y(CH2SiMe3)«2THF36 and ScCl3«3THF39 were prepared using previously reported synthesis. Y(CH2C6H4-o-NMe2)3. To a THF suspension of YCL/3THF (2.000 g, 4.859 mmol) was added 3.3 equiv of Li(CH2C6H4-o-NMe2) (2.260 g, 16.01 mmol) at -30 °C. The solution was stired at room temperature for 12 hours. The solvent was removed under vaccum to give a light yellow solid. The solid was extracted with toluene (2*50mL) and filtered. The volume was reduced to 15 mL and the solution cooled to -30 °C for 12 hours. White crystalline Y(CH2C6H4-o-NMe2)3 was isolated by filtration and dried under vaccum (1.720 g, 3.512 mmol, 72 %). 'H NMR 5 7.06 (dd, IH, Ph), 6.97 (m, IH, Ph), 6.82 (dd, IH, Ph), 6.65 (m, IH, Ph), 2.09 (s, 6H, NMc2), 1.62 (s, 2H, CH2). YC13{(BDPP)H2}*THF (2). To a 1,2-dichlorobenzene solution (25 mL) of ligand la (0.500 g, 1.092 mmol) was added one equiv of solid YC13-3THF (0.410 g, 1.000 mmol). The suspension was then heated in a 150 °C oil bath for 12 hours. The solution was cooled to 23 °C then added to 150 mL of cold hexanes resulting in immediate precipitation of a white solid. The solid (2) was isolated by filtration and was dried under vaccum at 60 °C for 12 hours (0.675 g, 0.928 mmol, 93 %). The 'H NMR spectrum of the hydrolysis product from this solid indicates that one THF molecule remains in the complex. (BDPP)Y(CH2SiMe3)*THF (3). Method A To an hexanes solution (15 mL) containing Y(CH2SiMe3)»2THF (0.100 g, 0.202 mmol) was added one equiv of the ligand la (0.092 g, 0.202 mmol) at room temperature. The solution changed from colorless to orange and was stirred for 12 hours. The solution was filtered and the solvent removed under vaccum. The solid was dissolved in a minimum ammount of hexanes and 2 drops of THF were added to the References start on page 253 252 solution. The solution was cooled to -30 °C for 12 hours. A white solid (3) was isolated by filtration and dried under vaccum (0.115 g, 0.163 mmol, 81 %). Method B To a THF solution (25 mL) of compound 2 (0.500 g, 0.690 mmol) was added 3.3 equiv of a diethylether solution of Me3SiCH2MgCl (1.93 mL, 1.18 M, 2.28 mmol) at -30 °C. The solution was stirred at room temperature for 12 hours. The solvent was removed under vaccum. The solid was extracted with hexanes (3*25mL) and filtered. The solvent was reduced to 15 mL and 2 drops of THF were added to the solution. The solution was cool to -30 °C for 12 hours. A white solid (3) was isolated by filtration and dried under vaccum (.398 g, 0.566 mmol, 82 %). 'H NMR 5 7.25-7.10 (m, 6H, Ar), 6.68 (t, 1H, py), 6.65 (d, 1H, py), 5.01 (br s, 4H, NCH2), 4.02 (br s, 4H, C#Me2), 3.22 (br s, 4H, THF), 1.35 (d s, 12H, CUMe2), 1.28 (d, 12H, CHMe2), 1.15 (br s, 4H, THF), 0.19 (s, 9H, CH2SiMe3), -0.38 (d, 2JYH = 3.6 Hz, 2H, C//2SiMe3). (BDPP)Y(CH2SiMe3)»Et20 (4). Complex 4 is obtained by recrystallisation of complex 3 from Et,0. 'H NMR 5 7.25-7.10 (m, 6H, Ar), 6.93 (t, 1H, py), (6.62 (d, 2H, py), 5.01 (AB quartet, 'J^ = 20.0 Hz, 4H, NC//2), 4.58 (sept, 2H, C#Me2), 3.53 (sept, 2H, C//Me2), 2.80 (q, 4H, MeO/20), 1.53 (d, 6H, CHMe2), 1.480 (d, 6H, CHMe2), 1.17 (d, 6H, CHMe2), 1.11 (d, 6H, CHM<?2), 0.23 (t, 6H, MeCH20), 0.21 (s, 9H, CH2SiM<?3), -0.33 (d, 2JYH = 3.6 Hz, 2H, C#2SiMe3). References start on page 253 253 5 References (1) Ziegler, K. Angew. Chem. 1964, 76, 545. (2) Ziegler, K.; Holzkamp, E.; Breil, H.; Martin, H. Angew. Chem. 1955, 67, 541. (3) Ewen, J. A. J. Am. Chem. Soc. 1984,106, 6355. (4) Jordan, R. F.; Bajgur, C. S.; Willet, R.; Scott, B. J. Am. Chem. Soc. 1986,107, 7410. (5) Jordan, R. F.; Lapointe, R. E.; Bajgur, C. S.; Echols, S. F.; Willet, R. J. Am. Chem. Soc. 1987, 109, 4111. (6) Jordan, R. F.; Bajgur, C. S.; Dasher, W. E.; Rheingold, A. L. Organometallics 1987, 6, 1041. (7) Jordan, R. F.; Lapointe, R. E.; Bradley, P. K.; Baenziger, N. Orgaiwmetallics 1989, 8, 2892. (8) Jordan, R. F.; Bradley, P. K.; Lapointe, R. E.; Taylor, D. F. New J. Chem. 1990,14, 505. (9) Jordan, R. F.; Bradley, P. K.; Baensiger, N. C; Lapointe, R. E. J. Am. Chem. Soc. 1990, 112, 1289. (10) Jordan, R. F.; Lapointe, R. E.; Baenziger, N.; Hinch, G. D. Organometallics 1990, 9, 1539. (11) Crowther, D. J.; Borkowsky, S. L.; Swenson, D.; Meyer, T. Y.; Jordan, R. F. Organometallics 1993, 72, 2897. (12) Massey, A. G.; Park, A. J. J. Organomet. Chem. 1964, 2, 245. (13) Chien, J. C. W.; Tsai, W.-M.; Rausch, M. D. J. Am. Chem. Soc. 1991, 775, 8570. (14) Coutts, R. S. P.; Wailes, P. C. J. Organomet. Chem. 1970, 25, 117. (15) Holton, J.; Lappert, M. F.; Ballard, D. G. H.; Pearce, R.; Atwood, J. L.; Hunter, W. E. J. Chem. Soc, Dalton Trans. 1979, 54. (16) Thompson, M. E.; Baxter, S. M.; Bulls, A. R.; Burger, B. J.; Nolan, M. C; Santarsiero, B. D.; Schaefer, W. P.; Bercaw, J. E. J. Am. Chem. Soc. 1987, 709, 203. References start on page 253 254 (17) Burger, B. J.; Thompson, M. E.; Cotter, W. D.; Bercaw, J. E. J. Am. Chem. Soc. 1990, 772, 1566. (18) Evans, W. J.; Peterson, T T; Rausch, M. D.; Hunter, W. E.; Zhang, H.; Atwood, J. L. Organometallics 1985, 4, 554. (19) Jeske, G.; Lauke, H.; Mauermann, H.; Swepston, P. N.; Schumann, H.; Marks, T. J. J. Am. Chem. Soc. 1985, 707, 8091. (20) Watson, P. L.; Parshall, G. W. Acc. Chem. Res. 1985,18, 51. (21) Watson, P. L. J. Am. Chem. Soc. 1982, 704, 337. (22) Schumann, H.; Rosenthal, E. C. E.; Kociok-Kohn, G.; Molander, G. A. J. Organomet. Chem. 1995, 496, 233. (23) Schumann, H.; Messe-Marktscheffel, J. A.; Hahn, F. E. J. Organomet. Chem. 1990, 390, 301. (24) Schumann, H.; Genthe, W.; Bruncks, N.; Pickardt, J. Organometallics 1982, 7, 1194. (25) Evans, W. J.; Dominguez, R.; Hanusa, T. P. Organometallics 1986, 5, 263. (26) Shapiro, P. J.; Bunel, E.; Schaefer, W. P.; Bercaw, J. E. Organometallics 1990, 9, 867. (27) Bradley, D. C; Copperthwaite, R. G.; Cotton, S. A.; Gibson, J. F.; Sales, K. D. J. Chem. Soc, Dalton Trans. 1973, 191. (28) Alyea, E. C; Bradley, D. C; Copperthwaite, R. G. J. Chem. Soc, Dalton Trans. 1973, 185. (29) Alyea, E. C; Bradley, D. C; Copperthwaite, R. G. J. Chem. Soc, Dalton Trans. 1972, 1580. (30) Ghotra, J. S.; Hursthouse, M. B.; Welch, W. J. J. Chem. Soc, Chem. Commun. 1973, 669. (31) Bradley, D. C; Ghotra, J. S.; Hart, F. A. J. Chem. Soc, Dalton Trans. 1973, 1021. (32) Bradley, D. C; Ghotra, J. S.; Hart, H. A. J. Chem. Soc, Chem. Commun. 1972, 349. References start on page 253 255 (33) Lappert, M. F.; Power, P. P.; Sanger, A. R.; Srivastava, R. C. Metal and Metalloid amides: Synthesis, Structures and Physical and Chemical Properties; John Wiley & Sons: Chichester, 1980. (34) Bradley, D. C; Copperthwaite, R. G. J. Chem. Soc, Chem. Commun. 1971, 764. (35) Cotton, F. A.; Wilkinson, G.; Gauss, P. L. Basic Inorganic Chemistry; 2nd ed.; Interscience: New York, 1387. (36) Lappert, M. F.; Pearce, R. J. Chem. Soc, Dalton Trans. 1973, 126. (37) Mu, Y.; Piers, W. E.; MacQuarrie, D. C; Zaworotko, M. J.; Jr., V. G. Y. Organometallics 1996, 15, 2720, (38) March, J. Advanced Organic Chemistry; Reactions, Mechanisms and Structure; 3rd ed.; Jon Wiley & Sons: New York, 1985. (39) Manzer, L. E. Inorg. Synth. 1982, 27, 135. References start on page 253 Appendix 1 MO calculation results: Input Control Parameters EHT option : Normal EHT Basis Contraction : ST0-3G Parameter K : 1.7500 Request MOs : HOMO -9999 to LUMO +3 Calculate dipole moment Net molecular charge = 0.0000 a.u. Standard parameters are from file: Alvarez Collected Parameters. Calculated Number of valence electrons = 56 Table 1. Character table for C2v-symmetry E c, ov(xz) av'(yz) 1 1 1 1 z 2 2 2 x , y , z 1 1 -1 -1 xy *i 1 -1 1 -1 xz B2 1 -1 -1 1 yz 257 Table 2. Alavarez parameters Element Orbital IP Ev Coeff exponent Coeff Exponent H Is 13.600 1.300 C 2p 11.400 1.625 2s 21.400 1.625 N 2p 13.400 1.950 2s 26.000 1.950 Zr 4d 11.180 0.621 3.835 0.577 1.505 5p 6.760 1.776 5s 9.870 1.817 258 Table 3. Orbital energies and labels 3, 2a„ -28.493 eV 4, 3a„ -27.001 eV 259 7, 3b„ -21.996 eV 8, 5a„ -19.718 eV 260 11, 5b„-16.260 eV 12, lb2, -16.091 eV 261 15, 8a„ -15.667 eV 16, 2bl5 -14.807 eV 262 17, 9a„ -14.788 eV 18, 5b„ -14.698 eV 19, 6b„ -14.358 eV 20, 10a,, -14.160 eV 263 23, 2%, -13.572 eV 24, 4b2, -13.028 eV 25, 9b„ -12.919 eV 26, 11a,, -12.728 eV 27, 3%, -12.429 eV 28, 12a„ -10.963 eV 265 31,4a2, -9.907 eV 32, 13a„ -9.017 eV 266 2 Crystallographic data for (BDMP)TiBr(CH2CMe2Ph). CO O Table . Crystal data and Empirical formula Formula weight Temperature Wavelength Crystal system Space group Unit cell dimensions Volume 2 Density (calculated) Absorption coefficient F(000) Crystal size 6 range for data collection Index ranges Reflections collected Independent reflections Refinement method Data / restraints / parameters Goodness-of-fit on F2 Final R indices [I>2a(I)] R indices (all data) Largest diff. peak .and hole 267 structure refinement details. C39 Uiit Br N3 Ti 682.58 298 (2) K 0.71073 A monoclinic P2,/n a = 14.892(2)A b « 14.741(3)A c * 16.080(3)A fi - 98.66(2)° 3489.8(12) A3 4 1.299 Mg m'3 1.421 mm"1 1424 0.29 X 0.24 X 0.15 mm 1.74 to 24.97° -K=h<=17, -K=k<=17, -19<=£<=18 7094 6115 [R(int) = 0.0323] Full-matrix least-squares on F2 6115 / 0 / 403 1.059 R, = 0.0706, wR2 - 0.1869 R, = 0.1769, WR2 = 0.2404 0.585 and -1.037 e A'3 268 Table . Atomic coordinates (x 106) and equivalent isotropic displacement parameters (A2 x 10 ) . Atom X y z U(eq) Ti 5764(1) -97(1) 2181 (1) 23(1) Br 5857(1) 1288(1) 1415(1) 62(1) N(l) 5250(4) 411(4) 3147(3) 24(1) N(2) 6130(4) -1032(4) 3181(3) 27(1) N(3) 6838 (4) -744(4) 1892 (4) 31(2) C(l) 5190(5) -129(5) 3897(4) 30(2) C(2) 5744(5) -962(5) 3883 (4) 27(2) C(3) 5913(6) -1620(6) 4507 (5) 39(2) C(4) 6500(6) -2308(5) 4417 (5) 40(2) C(5) 6934(6) -2335(5) 3713(5) 39(2) C(.6) 6748(5) -1682(5) 3107(4) 32(2) C(7) 7188(5) -1573(5) 2339(5) 37(2) C(8) 4631 (5) -758(5) 1480(4) 32(2) C(9) 4274(5) -1749(5) 1518(5) 32(2) C(10) 4948(6) -2394(6) 1253(6) 54(3) C(17) 3408 (6) -1837 (7) 865(5) 56(3) C(ll) 4011(5) -1963 (5) 2377(4) 31(2) C(12) 4363(6) -2694(6) 2851(5) 47(2) C(13) 4062(7) -2925(7) 3604(6) 62(3) C(14) 3435(7) -2411(7) 3906(6) 54(3) C(15) 3081(6) -1669 (7) 3454(6) 53(2) C(16) 3371(6) -1447(6) 2699(5) 43(2) C(21) 5045(5) 1344(5) 3284 (4) 26(2) C(22) 5727(6) 1916(5) 3662(5) 37 (2) C(23) 5533 (7) 2799(6) 3826(5) 51(2) C(24) 4670(8) 3119(6) 3618(6) 61(3) C(25) 3991(7) 2579(6) 3241(5) 49(2) C(26) 4158(6) 1682(6) 3064 (5) 39 (2) C(27) 3399(6) 1087(7) 2662(6) 59(3) C(28) 6689(6) 1579 (7) 3882(6) 53(2) 269 Atom X y Z U(eq) C(31) 7450(5) -424(5) 1347 (4) 31(2) C(32) 7304(5) -635(5) 486(5) 36(2) C(33) 7947(6) -332(6) -3(5) 45(2) C(34) 8691(7) 140(6) 323 (7) 58(3) C(35) 8829(6) 351(6) 1163(7) 54(3) C(36) 8211(5) 75(6) 1689(5) 43(2) C(37) 8377(6) 337 (7) 2599(6) 64(3) C(38) 6500(6) -1183 (7) 101(5) 53(3) C(41) 3504(14) 4998(17) 208(15) 135(7) C(42) 3512(15) 5312(11) 1002(19) 138 (8) C(43) 4001(16) 4831(18) 1641(13) 143(10) C(44) 4418(11) 4072(16) 1437(12) 125(6) C(45) 4401(11) 3820 (12) 661 (12) 111(5) C(46) 3955 (13) 4269(16) 85(10) 122(6) U(eq) is defined as one third of the trace of the orthogonalized Uij tensor. 270 Table Anisotropic displacement parameters (A2 x IO3) • Atom Un U22 U33 u23 Ti 26(1) 24 (1) 22 (1) 3(1) 7(1) KD Br 70(1) 57 (1) 63 (1) 12 (1) 20(1) -3(1) N(l) 25(3) 25(3) 25(3) 1(3) 9(3) 2(3) N(2) 31(3) 25(3) 26(3) 1(3) 8(3) 5(3) N(3) 25(3) 40(4) 32 (3) 2(3) 14 (3) -1(3) C(l) 33 (4) 32 (4) 28 (4) 3(3) 11(3) 0(4) C(2) 28 (4) 30(4) 24 (4) 7(3) 5(3) 0(3) C(3) 52 (5) 44 (5) 23 (4) 4 (4) 10(4) 1(4) C(4) 54 (5) 29 (5) 38 (5) 10(4) 2(4) 2(4) C(5) 42(5) 26(4) 49 (5) 9 (4) 6(4) 10(4) C(6) 35(4) 30(4) 30(4) -1(3) 3(3) 7(4) C(7) 34(5) 35(5) 44 (5) 6(4) 12 (4) 8(4) C(8) 35(4) 34(5) 27 (4) -3(3) 3(3) -5(4) C(9) 34 (4) 30(4) 32 (4) -4(3) 4 (4) -5(4) C(10) 74(7) 39(5) 56 (6) -10(4) 30(5) -15(5) C(17) 55(6) 76(7) 36(5) -5(5) 4 (4) -29(5) C(ll) 24 (4) 32(4) 34 (4) -2(4) -1(3) -5(4) C(12) 38(5) 53(6) 51(5) 7(5) 16(4) 4(4) C(13) 55 (6) 65 (7) 63 (6) 32 (6) 6(5) 5(6) C(14) 59 (6) 67 (7) 41(5) -1(5) 17 (5) -15(6) C(15) 56 (6) 52 (6) 57 (6) -12(5) 29(5) -5(5) C(16) 46(5) 39 (5) 48(5) 6(4) 18 (4) -2(4) C(21) 33 (4) 25 (4) 21(3) 1(3) 8(3) 3(3) C(22) 56(6) 32 (5) 27 (4) -1(4) 16 (4) 4(4) C(23) 71(7) 48(6) 37 (5) -3(4) 17 (5) -4(5) C(24) 111(9) 27 (5) 48(6) -7(4) 20(6) 24(6) C(25) 57 (6) 48(6) 45(5) 1(5) 15(5) 27(5) C(26) 44(5) 43(5) 31(4) 4 (4) 12 (4) 12(4) C(27) 39(5) 71(7) 67 (6) 2(5) 5(5) 18(5) C(28) 44(5) 56(6) 60(6) -20(5) 7(5) -10(5) C(31) 35(4) 28(4) 32 (4) 8(3) 12 (3) 14(4) C(32) 35(5) 34 (5) 41 (5) 5(4) 12 (4) 10(4) C(33) 48 (6) 50(6) 43 (5) 14 (4) 26(4) 17(5) C(34) 58(6) 46(6) 84 (7) 20(5) 51(6) 11(5) C(35) 43(6) 36(5) 90(8) -6(5) 31(5) -8(4) C(36) 36(5) 35(5) 62 (5) -4 (4) 18 (4) 8(4) C(37) 52 (6) 74 (7) 64 (6) -22(5) 7(5) -8(6) C(38) 55(6) 78(7) 28(4) -5(5) 9(4) 7(5) C(41) 129(17) 128(18) 146(18) 54(15) 16(14) -36(14) C(42) 149(19) 52(10) 233(26) -21(14) 88(20) -53(11) C(43) 160(21) 165(23) 121(16) -78(16) 77(15) -97(18) C(44) 97(12) 176(20) 99(13) 33(13) 7(10) -57(13) C(45) 110(12) 135(14) 90(11) -16(11) 23(10) 23(11) C(46) 133(15) 159(18) 70(10) -22(12) -2(10) 16(13) The anisotropic displacement factor exponent takes the form: -2 t2 [ h2 a*2 U„+ ... +2hk a* b* U12 ] 271 Table . Bond lengths [A] and angles [°]. Ti-N(3) 1. 977(6) Ti-N(l) 1. 979(5) Ti-C(8) 2. 121(7) Ti-N(2) 2. 126(6) Ti-Br 2. 399(2) N(l)-C(21) 1. 433(9) N(l)-C(l) 1. 458(8) N(2)-C(2) 1. 344(9) N(2)-C(6) 1. 346(9) N(3)-C(31) 1. 435(9) N(3)-C(7) 1. 473(9) C(l)-C(2) 1. 481(10) C(2)-C(3) 1. 391(10) C(3)-C(4) 1. 361(11) C(4)-C(5) 1. 385(11) C(5)-C(6) 1. 369(10) C(6)-C(7) 1. 491(10) C(8)-C(9) 1. 558(10) C(9)-C(10) 1. 490(11) C(9)-C(ll) 1. 525(10) C(9)-C(17) 1. 542(10) C(ll)-C(12) 1. 377(11) C(ll)-C(16) 1. 380 (11) C(12)-C(13) 1. 396(11) C(13)-C(14) 1. 347 (13) C(14)-C(15) 1. 375(13) C(15)-C(16) 1. 386(11) C(21)-C(22) 1. 387(11) C(21) -C(26) 1. 407(10) C(22)-C(23) 1 368 (12) C(22)-C(28) 1. 507(12) C(23)-C(24) 1 363(13) C(24)-C(25) 1. 355(13) C(25)-C(26) 1 383(11) C(26)-C(27) 1 498(12) C(31)-C(36) 1 .392(11) C(31)-C(32) 1 404(10) C(32)-C(33) 1 .401(11) C(32)-C(38) 1. 498(11) C(33)-C(34) 1 .346(13) C(34)-C(35) 1. 370(13) C(35)-C(36) 1 .402(11) C(36)-C(37) 1. 498(11) C(41)-C(46) 1 .30(2) C(41)-C(42) 1 .36(2) C(42)-C(43) 1 .37(3) C(43)-C(44) 1 .34(2) C(44)-C(45) 1 .30(2) C(45)-C(46) 1 •25(2) N(3)-Ti-N(l) 142 •1(2) N(3)-Ti-C(8) 105. 1(3) N(l)-Ti-C(8) 102 • 7(3) N(3)-Ti-N(2) 75. 0(2) N(l)-Ti-N(2) 74 .7(2) C(8)-Ti-N(2) 101. 4(3) N(3)-Ti-Br 100 .3(2) N(l)-Ti-Br 98. 1(2) C(8)-Ti-Br 102 .8(2) N (2)-Ti-Br 155. 8(2) C(21)-N(l)-C(l) 110 .9(5) C(21)-N(l)-Ti 126. 8(4) C(l)-N(l)-Ti 121 .4(4) C(2)-N(2)-C(6) 120. 9(6) C(2)-N(2)-Ti 119 • 4(5) C(6)-N(2)-Ti 119. 7(5) 272 C(31)-N(3)-C(7) 111.1(6) C(7)-N(3)-Ti 121.7(5) N(2)-C(2)-C(3) 119.9(7) C(3)-C(2)-C(l) 127.4(7) C(3)-C(4)-C(5) 119.7(7) N(2)-C(6)-C(5) 120.3(7) C(5)-C(6)-C(7) 126.7(7) C(9)-C(8)-Ti 131.2(5) C(10)-C(9)-C(17) 106.4(7) C(10)-C<9)-C(8) 109.8(6) C(17)-C(9)-C(8) 107.9(6) C(12)-C(ll)-C(9) 122.3(7) C(ll)-C(12)-C(13) 121.7(8) C(13)-C(14)-C(15) 119.2(9) C(ll)-C(16)-C(15) 121.4(8) C(22)-C(21)-N(l) 119.5(7) C(23)-C(22)-C(21) 120.1(8) C(21)-C(22)-C(28) 120.7 (7) C(25)-C(24)-C(23) 121.2(9) C(25)-C(26)-C(21) 118.5(8) C(21)-C(26)-C(27) 121.3(7) C(36)-C(31)-N(3) 119.1(7) C(33)-C(32)-C(31) 117.8(8) C(31)-C(32)-C(38) 121.5(7) C(33)-C(34)-C(35) 119.6(8) C(31)-C(36)-C(35) 119.0(8) C(35)-C(36)-C(37) 119.2(8) C(41)-C(42)-C(43) 117(2) C(45)-C(44)-C(43) 122 (2) C(45)-C(46)-C(41) 124(2) C(31)-N(3)-Ti N(1)-C(1)~C(2) N(2)-C(2)-C(l) C(4)-C(3)-C(2) C(6)-C(5)-C(4) N(2)-C(6)-C(7) N(3)-C(7)-C(6) C(10)-C(9)-C(ll) C(ll)-C(9)-C(17) C(ll)-C(9)-C(8) C(12)-C(ll)-C(16) C(16)-C(ll)-C(9) C(14)-C(13)-C(12) C(14)-C(15)-C(16) C(22)-C(21)-C(26) C(26)-C(21)-N(l) C(23)-C(22)-C(28) C(24)-C(23)-C(22) C(24)-C(25)-C(26) C(25)-C(26)-C(27) C(36)-C(31)-C(32) C(32)-C(31)-N(3) C(33)-C(32)-C(38) C(34)-C(33)-C(32) C(34)-C(35)-C(36) C(31)-C(36)-C(37) C(46)-C(41)-C(42) C(44)-C(43)-C(42) C(46)-C(45)-C(44) 126.5(5) 109.7(6) 112.7(6) 119.5(7) 119.5(7) 112.9(6) 109.0(6) 113.7 (7) 107.3(6) 111.4(6) 116.8(7) 120.8(7) 120.4(9) 120.4(9) 119.5(7) 121.0(7) 119.2(8) 120.0(9) 120.6(9) 120.2(8) 120.1(7) 120.7(7) 120.8(7) 122.6(8) 120.9(9) 121.8(7) 120(2) 118(2) 120(2) 273 Table Hydrogen atom coordinates (x 104) and isotropic displacement parameters (A2 x 103) . Atom H(1A) H(1B) H(3) H(4) H(5) H(7A) H(7B) H(8A) H(8B) H(10A) H(10B) H(10C) H(17A) H(17B) H(17C) H(12) H(13) H(14) H(15) H(16) H(23) H(24) H(25) H(27A) H(27B) H(27C) H(27D) H(27E) H(27F) X y Z U(eq 4562 -291 3914 33 5409 223 4396 33 5628 -1590 4982 43 6610 -2757 4825 45 7348 -2794 3653 43 7842 -1530 2496 41 7056 -2096 197 5 41 4116 -382 1558 36 4713 -675 898 36 5086 -2219 711 60 4699 -2995 1222 60 5493 -2382 1657 60 2951 -1430 1008 62 3187 -2449 862 62 3545 -1687 317 62 4813 -3043 2664 51 4294 -3436 3900 68 3245 -2557 4415 60 2645 -1313 3655 58 3128 -939 2404 47 5991 3181 4080 56 4544 3719 3737 67 3409 2814 3101 54 3600 475 2673 65 3218 1271 2095 65 2898 1138 2961 65 2878 1448 2480 65 3260 651 3058 65 3580 785 2192 65 Atom X y Z U(eq) H(28A) 6750 1017 3608 59 H(28B) 6828 1498 4474 59 H(28C) 7094 2010 3704 59 H(28D) 7031 2000 4249 59 H(28E) 6953 1519 3383 59 H(28F) 6688 1006 4153 59 H(33) 7856 -461 -576 49 H(34) 9108 322 -19 64 H(35) 9340 683 1387 60 H(37A) 8948 632 2722 70 H(37B) 8376 -191 2937 70 H(37C) 7911 737 2714 70 H(37D) 7875 154 2860 70 H(37E) 8447 977 2645 70 H(37F) 8913 49 2868 70 H(38A) 6344 -1025 -475 59 H(38B) 6001 -1062 389 59 H(38C) 6647 -1810 146 59 H(38D) 6317 -1573 515 59 H(38E) 6660 -1536 -349 59 H(38F) 6014 -788 -106 59 H(41) 3179 5304 -246 149 H(42) 3196 5834 1107 152 H(43) 4045 5022 2197 157 H(44) 4727 3716 1865 137 H(45) 4721 3308 536 122 H(46) 3943 4069 -465 135 3 Crystallographic data for (BDPP)Ti(C4a,P'-(SiMe3)H2). ro cr CM CO o 00 ro O O ro 5 ro O 276 Table Sl. Crystal Data and Experimental Details Empirical formula Formula weight Temperature Wavelength Crystal system Space group Unit cell dimensions Volume z Density, calcd. Absorption coefficient F(000) Reflections Collected Independent reflections Refinement method Data/restraints/parameters Goodness-of-fit (GooF) on F2 Final R indices [I>2sigma (I)] R indices (all data) C4iH6iN3Si2Tii 700.01 25°C 0.71073 A Monoclinic P2i/n a = 10.630(3)A b = 36.650(9)A c = 12.200(4)A P = 110.73 (2)° 4445(2) A3 4 1.046 g. cm""' 0.274 mm'1 1512 6646 5362 [R(int) = 0.0921] Full-matrix least-squares on F' 1848/127/258 0.996 RI = 0.1017, wR2 = 0.2030 RI = 0.2750, wR2 = 0.2733 RI = I ( | Fe I - I Fe I) /I I Fe I ; Kft2 = [Zw(F02 - Fc2)2/IwF04]1/2 GooF = [Zw(F02 - Fc2)2/(n-p) ]1/2 where n is the number of reflections and p is the number of parameters refined. 277 Table S2. Atomic coordinates ( x 10*) displacement parameters (A2 defined as one third of the Uij tensor. and equivalent isotropic x 103) . U(eq) is trace of the orthogonalized atom X y z Ueq Ti (1) 5915.8 (19) 1110.0 (5) 2385.1(16) 47.1 (6) Si (1) 2511 (4) 1474(1) 782 (3) 74(1) Si (2) 7730 (4) 2171 (1) 2116(4) 101 (2) N(l) • 5975(8) 754 (2) 1173 (7) 50 (2) N(2) 5953(8) 1134(2) 4042(6) 46 (2) C (1) 7552(12) 1421 (3) 2488 (9) 60 (3) C (2) 6812(11) 1720 (3) 2041 (9) 51 (3) C(3) 5251 (11) 1730 (3) 1515(9) 67 (4) C(4) 4367 (10) 1458 (3) 1472(8) 51 (3) C(5) 1665(13) 1945 (3) 279 (13) 151 (7) C(6) 1970(13) 1168 (4) -527(10) 135(6) C(7) 1715 (12) 1305 (3) 1820 (10) 111 (5) C(8) 6598 (22) 2573(6) 1634 (19) 130(6) C(9) 9014 (21) 2149 (7) 1462 (19) 130 (6) C(10) 8683 (22) 2249(6) 3792 (13) 130 (6) C (8A) 6898 (33) 2579(8) 2379 (27) 136 (9) C(9A) 7698 (34) 2198 (9) 511(17) 136(9) C(10A) 9540(20) 2153 (10) 3017(25) 136 (9) C(ll) 5123 (11) 892 (3) 4474 (9) 59(3) N(3) 4880(8) 624(2) 2634(7) 46(2) C(12) 4562(10) 587 (3) 3617(9) 53 (3) C(13) 3791 (11) 294 (3) 3760(10) 71(4) C(14) 3370 (12) 40(3) 2861 (10) 79(4) C(15) 3721(11) 64 (3) 1866 (10) 66 (4) C(16) 4508(10) 363 (3) 1788 (9) 54 (3) C(17) 5080(11) 437 (3) 858 (9) 67(4) 278 C(18) C(19) C(20) C(21) C(22) C(23) C(24) C(25) C(26) C(27) C(28) C(29) C (28A) C(29A) C (30) C (31) C(32) C(33) C(34) C (35) C(36) C{37) C{38) C(39) C(40) C(41) 6653(8] 5965 (6: 6633 (8: 7988 (8! 8676 (6] 8009 (8! 4491 (11) 4290 (14) 3558 (12) 8817(11) 10243(21) 8962(30) 10357(18) 8463(31) 6901 (7) 6584 (6) 7463 (9) 8657(8) 8974 (6) 8096(8) 5257 (13) 5441(18) 4343 (13) 8509 (13) 8460(17) 9893 (13) 1409 (2) 1703(2) 1947 (2) 1896 (2) 1602 (2) 1358 (2) 1785 (3) 2167 (3) 1759(3) 1044 (3) 1204(8) 721(7) 1060 (8) 664 (7) 747 (2) 929 (2) 917 (2) 722 (2) 539 (2) 551 (2) 1127 (4) 1533 (4) 926(4) 353 (3) -68(3) 463 (4) 4900(6) 63 (3) 5138(6) 56(3) 6027 (7) 88 (4) 6679(6) 101(5) 6441(7) 109 (5) 5551(7) 69 (4) 4393 (10) 67 (4) 3805(11) 106 (5) 5124 (10) 89 (4) 5286 (10) 73 (4) 5425 (32) 107 (10) 6095 (25) 107(10) 5691 (30) 100 (10) 5732 (29) 100 (10) 515 (7) 58 (3) -547 (7) 69 (4) -1161 (5) 94 (4) -714 (7) 90 (4) 348 (7) 89 (4) 962 (5) 73 (4) -1130(11) 93 (4) -1377(12) 172(8) -2246 (11) 135(6) 2159(10) 81 (4) 1990 (14) 178(9) 3028(11) 126 (6) 279 C(9)-Si(2)-C(8) C(8A)-Si(2)-C(2) C(8)-Si(2)-C(2) C(10A)-Si(2)-C(9A) C(9)-Si(2)-C(10) C(2)-Si(2)-C(10) C(17)-N(l)-Ti (1) C(18)-N(2)-C(ll) C(ll)-N(2)-Ti(1) C(l)-C(2)-C(3) C(3)-C(2)-Si (2) C{3.)-C(2)-Ti(l) C(4)-C(3)-C(2) C(2)-C(3)-Ti (1) C(3)-C(4)-Ti(1) N(2)-C(11)-C(12) C(12)-N(3)-Ti(1) N(3)-C(12)-C(13) C (13)-C(12)-C(11) C(13)-C(14)-C(15) C(15)-C(16)-N{3) N(3)-C(16)-C(17) C(19)-C(18)-N(2) C(20)-C(19)-C(24) C(22)-C(23)-C{27) C (19)-C(24)-C(25) C(25)-C(24)-C(26) C(28A)-C{27)-C(23) C(23)-C(27)-C(28) C(23)-C(27)-C(29A) C(35)-C<30)-N(l) C(32)-C(31)-C(36) C(30)-C(35)-C(39) C(31)-C(36)-C(38) C(41)-C(39)-C(35) C(35)-C(39)-C(40) 113.6(9) C(9)-Si(2)-C(2) 113.1(9) 116.6 (14) C(10A)-Si(2)-C(2) 113.9(12) 114.1 (9) C(8A)-Si(2)-C(9A) 107.3(11) 104.1(11) C(2)-Si (2)-C(9A) 99.7 (11) 106.0(9) C(8)-Si(2)-C(10) 104.7 (9) 104.1(8) C(17)-N(l)-C(30) 109.8(7) 121.8(6) C(30)-N(l)-Ti(l) 128.3(6) 112.3 (7) C(18)-N(2)-Ti(l) 125.3(6) 122.1 (6) C(2)-C(l)-Ti(1) 93.9(8) 124.8(10) C(l)-C(2) -Si (2) 118.1 (8) 117.1(8) C(l)-C(2)-Ti(l) 53.9(6) 71.2 (6) Si(2)-C(2)-Ti(l) 167.9(6) 128.6 (10) C(4)-C(3)-Ti(1) 55.8(6) 72.8(6) C(3)-C(4)-Si (1) 127.4 (9) 91.3 (7) Si(l)-C(4)-Ti(l) 141.2(6) 109.9(8) C(12)-N(3)-C(16) 120.1 (9) 120.0 (7) C (16)-N(3)-Ti(1) 119.8(7) 121.7(10) N(3)-C(12)-C(ll) 112.2 (9) 126.1 (10) C(14)-C(13)-C(12) 117.1 (11) 122.3 (13) C(16)-C(15)-C(14) 117.4(11) 121.2 (10) C(15)-C(16)-C(17) 127.5 (10) 111.2 (10) N(l)-C(17)-C(16) 110.3 (9) 121.0 (7) C(23)-C(18)-N(2) 118.8(7) 117.9 (7) C(18)-C(19)-C(24) 122.0 (7) 118.4(7) C(18)-C(23)-C(27) 121.5 (7) 113.1 (10) C(19)-C(24)-C(26) 111.9 (9) 108.1 (9) C(29)-C(27)-C(23) 113 (2) 121 (2) C(29)-C(27)-C(28) 110.4 (14) 107(2) C(28A)-C(27)-C(29A) 106.2(14) 112 (2) C(31)-C(30)-N(l) 120.6(7) 119.4(7) C(30)-C(31)-C(36) 123.0(8) 116.9(8) C(34)-C(35)-C(39) 118.2(7) 121.7(7) C(31)-C(36)-C(37) 113.0(11) 112.0(10) C(37)-C(36)-C(38) 111.7(10) 114.4(10) C(41)-C(39)-C(40) 109.3(10) 110.8(10) 280 Table S3. Bond Distances (A) ,and 'Angles (°) Ti (1) -N(l) 1. 989(8) . Ti (.1) -N.(2) 2 . 009(8) Ti (1) -N(3.)' 2 . 172(8); Ti (1) -C(l) 2 . 046(11) Ti (1) -C(4) 2 . 07 0 (10) . . Si (1) -C(4) 1. 852(11) Si (1) -C(5) 1. 881(10) Sid) -CC6) 1. 867(11) Si (1) -C(7) 1. 860 (11) Si(2) -C(2) il. 904(10) Si (2) -C(8). - 1. 86(2). '. Si(2) -C(9) 1. 81 (2) Si (2) -C(10) 1. 96 (2) • Si(2) -C(8A) 1. 82 (2) Si (2) -C(9A) 1. 95 (2) Si (2.) -C(10A) 1. 85(2) N (1) - C(17) . 1. '465(11) . N (1) -C(30) • .1. 474 (9) N (2 )' -C (Hi • 1. 476(11) ' N (2) - G (18) : I . 453 (9) N(3)- C(12) 1. 363 (11);; N (3 ) - Cd'6) , i' 359 (11) C (1 ) -C (2) 1 348 (13) C(2)- C (3)' I 553 (14) C (3) - C (4 ) i '3 57 (13) C(ll') -C(12) " i 5 02 (12) C (12 ) -C(12) 1 3S9 (13) C(12) -C (14) • i 3 87.(14) C (14 ) -CH5! 1 393(13)• • C (15 ) -C(16) i .400 (13) C (16) -C (17.) I 49i'(13) C (19) -C(24) • i .537(11) C (2 3 ) -C(2") 1 .539 (.12) C(24) -C(25) . . i ..554 (12) C{24) -C (26) 1 .554 (12) C(27 -CH28) . i . 58 (2.) C (27) -C (29) x .51 (2) C(27. -C(28A) i .53 (2) . C (27) -C(29k) • • 1 .59(2) C (31 -C(36) • ' i . 520 (13) C (36) -C (37) 1 .546 (13) '*C(36. -C'(38) • I . 551 (13) C (35 j -C(39) J. .546(12) C (39 -C(40)' i .557(13) C (3? -C(41) . 1 .531 (12) . K (1.) -Tl(1) -N(2)- .'' 141. 5(3) • Nd)' - Tl (1)' -C (1) 9-9 .2(4) N (2 ) -Tl(1) -C(l) 101. 5 (4) Nd) -Ti(1) -C(4) 1'0.3 .4(4) N(2) -Tl(1) -C(4) 104 . 0(4) Cd) -Tl (1). -C(4) 100 .7(4) N.(1) -Ti(1) -N(3) 73. 6(3) N(2) -Ti(1) -N(3) 74 .1(3) C(l) -Ti(1) -N(3) 155. 6 (4) C(4) -Ti(1) -N.(3). 103 .6 (4) Nd) -Ti (1 ) -C-(3) 111. 0(3) N(2.) -Ti (1) -C(3) 106 .8(3) C(l) -Tl(1) -C(3) 68. 1 (4) C(4) -Ti(1) -C(3) 32 .8(3) N(3) -Ti(1) -C(3) . • 136. 4(3) N(l) -Ti(1) -C(2) ' 110 .1(3) N(2) -Ti(1) -C(2) 104. 7 (3) Cd) -Ti(1) -C(2) .32 .2(3) C(4) -Ti.(l) -C(2) 68. 8(4) N(3) -Ti(1) -C(2.) 172 .0(3) C(3) -Tl(1) -C(2) 36. 0(3) C (4) -Si(1) -C(7) 110 .4(5) C(4) -Sl(1) -C(6) 109. 1(5) C(7) -Si.(l) -C(6) 107 .9(6) C(4) -Si(1) -C(5) 112 4 (6) C(7) -Si'(l) -C(5) 109 .1(6) C(6) -Si(1) -C (5) 107 8(6) C (8A )-Si(2 )-C(10A) 113 .1 (12) 281 Table S4. Anisotropic displacement parameters (A2 x 103) . The anisotropic displacement factor exponent takes trie form: -2nJ [hV2UU + ... + 2hkaVui2] atom Ti(l) Si (1) Si(2) C(5) C(6) C(7) C(25) C(26) C(37) C(3B) C(40) C(41) Ull 53(1) 60 (2) 84(3) 92 (12) 80(11) 79(11) 171 (15) 94(11) 308(26) 110 (13) 189 (20) 91 (12) U22 46(1) 79(3) 65(3) 111(13) 202(18) 153(14) 57(9) 98(11) 116 (14) 179 117) 78(12) 154 (15) 1333 46(1) 81(3) 164(5) 230(19) 120(13) 98(11) 111(12) 89(10) 125(15) 90 (12) 199 (19) 102(12) U23 3(1) 13(2) 25(3) 75(13) -68(13) 12(10) 16(8) 9(8) 57(12) -2(12) 15(13) -24(11) U13 22(1) 23(2) 57(3) 32 (13) 30(10) 26(9) 76(11) 49(9) 118(16) 5 (10) -14 (15) -4 (10) U12 0(1) 9(2) -10(2) 37(11) -33(12) -10(10) 17(10) 29(9) 48(16) 21(12) 7 (13) -9(11) Table S5. Calculated hydrogen atoms positions (x 104) and isotropic thermal parameters (x 103) . Atom H(1A) H(3) H(5A) H(5B) H(5C) H(6A) H(6B) H(6C) H(7A) H(7B) H(7C) H(8A) H(8B). H(8C) H(9A) HOB) HOC) H(10A) H(10B) H(10C) H(8A1) H(8A2) H(8A3) HOA1) X y z 8470 (12) 1373 (3) 2748 (9) 4872 (11) 1951 (3) 1186 (9) 907 (19) 1938(7) -96(99) 2265(98) 2032 (14) -267 (84) 2103 (110) 2106(8) 942 (19) 1010 (17) 1179(24) -899 (59) 2238(101) 922(6) -287(16) 2385(93) 1247 (19) -1070(46) 1992(75) 1058(9) 2039(64) 754 (12) 1314(24) 1450(31) 1988(76) 1456(16) 2507(38) 7113 (35) 2793 (6) 1870(145) 5921(112) 2563(27) 1986(131) 6175(149) 2569(29) 796(23) 8655(60) 2032(45) 712 (74) 9769(79) 2012(43) 1964(80) 9299(131) 2391(7) 1365(146) 9067 (161) 2023 (12) 4154(32) 8065(46) 2338(49) 4144(33) 9386(125) 2425(39) 3902 (13) 6693 (269) 2547(33) 3078(147) 6081(154) 2619(47) 1725(121) 7482 (121) 2785 (16) 2471(258) 6784 (36) 2214(82) -19(23) Ueq 72 80 227 227 227 203 203 203 167 167 167 195 195 195 195 195 195 195 195 195 203 203 203 203 282 H(9A2) H(9A3) H(10D) H(IOE) H(IOF) H(11A) H(11B) H(13) H(14) H(15) H(17A) H(17B) H(20) H(21) H(22) H(24) H(25A) H(25B) H (25C) H(26A) H(26B) H(26C) H(28A) H(265) H(28C) H(29A) H(29B) H(29C) H{28D) H(28E) H(28F) H(29D) H(29E) H(29F) H{32) H(33) H(34) H(36) H(37A) H(37B) H(37C) H(38A) H(38B) H(38C) H(39) H(40A) H(40B) H(40C) H(41A) H(41B) H(41C) 8111 (271) 8184 (256) 9646 (20) 9953 (62) 9962(62) 4392 (11) 5666 (11) 3570(11) 2835 (12) 3444 (11) 5577(11) 4356(11) 6172 (12) 8434 (12) 9583(6) 4194(11) 4368 (90) 3415 (36) 4965 (55) 2648 (17) 3839 (51) 3612(62) 10133(22) 10751(75) 10713 (80) 9746 (118) 9053 (198) 8180 (96) 10626 (20) 10676(22) 10733(19) 7528(55) 8646(188) 9001 (146) 7251 (12) 9245 (10) 9774 (7) 4784(13) 6026(118) 4582(26) 5830(136) 3434(25) 4376(92) 4652(73) 7843(13) 8490(150) 9218(82) 7643 (71) 10569(17) 10075(46) 9902 (35) 1984(39) 2410(46) 2106(80) 2382(29) 1962(53) 1030(3) 792(3) 270(3) -154(3) -110(3) 225 (3) 483(3) 2144(2) 2059(3) 1568(4) 1602(3) 2352(3) 2180(9) 2206(10) 1809 (21) 1933 (15) 1517 (7) 1418(33) 1025 (22) 1269 (48) 754 (28) 502(10) 704 (31) 1290(23) 866(33) 1035 (51) 610 (27) 676 (18) 475(10) 1039(3) 714(3) 408(3) 1122(4) 1648(10) 1653(10) 1552(4) 1011(24) 668(5) 975(26) 416(3) -185(4) -145(6) -134(5) 407(26) 330(21) 719(6) 338(87) 424 (70) 3819 (52) 2965(204) 2735(165) 4573(9) 5229(9) 4429(10) 2924 (10) 1277(10) 759(9) 119(9) 6187 (10) 7275(8) 6878 (9) 3770 (10) 4383 (18) 3205 (54) 3461 (68) 4629 (19) 5750(43) 5444(58) 4943 (139) 5187(156) 6230 (48) 6786 (85) 5701 (68) 6312 (136) 5467(155) 5331 (126) 6528 (31) 5331 (132) 6560 (45) 5573(155) -1872(6) -1126(10) 647(10) -571(11) -673 (35) -1636(121) -1975(92) -2448(61) -2100(34) -2882(28) 2515(10) 2703(45) 1794(126) 1368(89) 2700(39) 3746(34) 3184(70) 203 203 203 203 203 71 71 86 95 80 80 80 106 122 131 81 159 159 159 134 134 134 160 160 160 160 160 160 151 151 151 151 151 151 113 108 107 111 258 258 258 202 202 202 98 266 266 266 189 189 189 283 Table S6. Selected torsion angles 50. 98 (96) N2-Til-Nl-C17 -83. 54 (78) C4-TH-N1-C17 -117. 08(75) C3-TU-N1-C17 -125. 48 (74) N2-TH-N1-C30 99. 99(78) C4-Til-Nl-C30 66. 46(80) C3-TU-N1-C30 140. 97(68) Nl-Til-N2-C18 -84. 65(75) C4-TH-N2-C18 -50. 66(75) C3-TH-N2-C18 -46. 30(94) N1-TH-N2-C11 88. 08(75) C4-Til-N2-Cll 122. 07(73) C3-Til-N2-Cll 113. 29(68) N1-TH-C1-C2 7. 58(73) C4-TH-C1-C2 4. 29 (62) C3-TH-C1-C2 169-. 23(56) Til-Cl-C2-Si2 88. 35 (71) N2-TH-C2-C1 168. 8(2.1) N3-TH-C2-C1 98. 33 (57) N1-TH-C2-C3 173. 23(98) Cl-Til-C2-C3 -17. 9(2.6) N3-TH-C2-C3 36. 3(2.7) N2-Til-C2-Si2 136 0 (2.7) C4-Til-C2-Si2 134 7(2.9) C3-Til-C2-Si2 -172 62 (93) Si2-C2-C3-C4 6 66 (97) C1-C2-C3-TH 82 25 (72) Nl-Til-C3-C4 174 02 (78) Cl-Til-C3-C4 177 .9(1.0) C2-TH-C3-C4 92 .07(57) N2-TH-C3-C2 -177 .9(1.0) C4-TH-C3-C2 -177 .20(77) C2-C3-C4-SH 2 .6 (1.2) C2-C3-C4-Til 99 .27 (68) N2-Til-C4-C3 175 .99(63) N3-TH-C4-C3 71 .72(90) Nl-Til-C4-Sil 174 .05(84) Cl-Til-C4-Sil 179 .6(1.3) C3-Til-C4-Sil -173 .11(76) C18-N2-C11-C12 168 .50(79) Nl-Til-N3-C12 92 .6(1.1) Cl-Til-N3-C12 -88 .10(83) C3-TH-N3-C12 -13 .94(72) N1-TH-N3-C16 -89 .8(1.1) Cl-Til-N3-C16 89 .46(84) C3-Til-N3-C16 -3 .3(1.5) C16-N3-C12-C13 176 .92(87) C16-N3-C12-C11 -4 .0(1.2) N2-C11-C12-N3 0 .4(1.6) N3-C12-C13-C14 -173 .98(87) C12-N3-C16-C17 172. 98 (76) C1-TH-N1-C17 16. 95(71) N3-TH-N1-C17 -155. 61(71) C2-TH-N1-C17 -3. 49(82) Cl-Til-Nl-C30 -159. 51(79) N3-Til-Nl-C30 27. 93(83) C2-TH-N1-C30 19. 66(78) C1-TH-N2-C18 174. 90(75) N3-TH-N2-C18 -13. 27 (76) C2-TH-N2-C18 -167. 60(73) C1-TH-N2-C11 -12. 37(68) N3-TH-N2-C11 159. 47(69) C2-TH-N2-C11 -99. 33(68) N2-Til-Cl-C2 -176. 26 (72) N3-TH-C1-C2 -7. 8(1.1) TH-C1-C2-C3 -74. 90(73) Nl-Til-C2-Cl -172. 01 (77) C4-TH-C2-C1 -173 23(98) C3-TH-C2-C1 -98 42 (57) N2-TH-C2-C3 1 22(58) C4-TH-C2-C3 -126 8(2.6) Nl-Til-C2-Si2 -51 9(2.4) Cl-Til-C2-Si2 116 7 (2.9) N3-Til-C2-Si2 4 .4(1.8) C1-C2-C3-C4 -2 2(1.0) TH-C2-C3-C4 -170 .40 (66) Si2-C2-C3-Til -90 .02(70) N2-TH-C3-C4 -5 .65(89) N3-TH-C3-C4 -95 .66 (57) N1-TH-C3-C2 -3 .88 (57) C1-TH-C3-C2 176 .45(52) N3-TH-C3-C2 -179 .7(1.0) Til-C3-C4-Sil -107 .96(67) Nl-Til-C4-C3 -5 .64(74) C1-TH-C4-C3 -1 .32(63) C2-TH-C4-C3 -81 .04(89) N2-Til-C4-Sil -4 .32(94) N3-Til-C4-Sil 178 .37(96) C2-Til-C4-Sil 13 .2(1.0) Til-N2-Cll-C12 9 .75(71) N2-Til-N3-C12 -91 .25(76) C4-Til-N3-C12 -72 .8(2.5) C2-Til-N3-C12 -172 .70(80) N2-TU-N3-C16 86 .31(79) C4-Til-N3-C16 104 .7(2.3) C2-Til-N3-C16 174 .17(76) TH-N3-C12-C13 -5 .5(1.1) Til-N3-C12-Cll 176 .25(95) N2-C11-C12-C13 -173 .44 (74) Til-N3-C16-C15 8 .4(1.1) Til-N3-C16-C17 284 159.13 (81) -173.20(96) -73.28(84) 101.55(74) 174.77(71) -9.11 (84) -90.02(74) 90.53(74) C30-N1-C15-C16 C11-N2-C11-N2 N2-C18 N2-C18-Til-Nl-Til-Nl-C17-C16 -C17-N1 C18-C19 C18-C23 C19-C20 C19-C24 C30-C31 C30-C35 -17.9(1.1) 4.7 (1.2) 100.06(65) -85.11(69) 176.12(76) 93.18(77) -86.27(76) Til-Nl-C17-C16 N3-C16-C17-N1 Til-N2-C18-C19 T11-N2-C18-C23 C23-C18-C19-C24 C17-N1-C30-C31 C17-N1-C30-C35 Table S7. Least-squares planes (x,y,z in crystal coordinates) and deviations from them (* indicates atom used to define plane) - 3.704(39) x + 9.282(340) y + 11.802(30) z = 1.465(59) * -0.008 (0.003) CI • 0.016 (0.007) C2 * -0.017 (0.007) C3 * 0.008 (0.003) C4 0.189 (0.018) Til -0.105 (0.015) Sil 0.184 (0.023) Si2 Rms deviation of fitted atoms = 0.013 7.621(30) x - 18.263(0.130) y + 2.467(37) z = 3.307(25) Angle to previous plane (with approximate esd) =86.33(3 0 158 (0.003) Nl * 0.156 (0.003) N2 * -0.077 (0.002) N3 * -0.237 (0.004) Til Rms deviation of fitted atoms = 0.167 4 Crystallographic data for (BDEP)ZrMe2. 285 286 Table SI. Crystal Data and Experimental Details Empirical formula Formula weight Temperature Wavelength Crystal system Space group Unit cell dimensions Volume 2 Density, calcd. Absorption coefficient F(000) Reflections Collected Independent reflections Refinement method Data/restraints/parameters Goodness-of-fit (GooF) on F" Final R indices [I>2sigma(I)] R indices (all data) C29H39N3Zri 520.85 256C 0.71073 A Monoclinic P2i/c a = 12.355(2)A b = 15.761(2)A c = 15.701(3)A (3 = 111.71(1)° 2840.5(8) A3 4 1.218 g.cm° 0.406 mm"1 1096 5706 4950 [R(int) = 0.0322] Full-matrix least-squares on F2 3011/42/244 1.038 RI = 0.0592, wR2 = 0.1335 RI = 0.1113, wR2 = 0.1657 RI = I ( | Fc I - I Fe I ) /I I F0 I ; wR2 = [Zw(F02 - Fc2)2/XwF04]1/2 GooF = [Xw(F02 - Fc2)2/(n-p) )1/2 where n is the number of reflections and p is the number of parameters refined. 287 Table S2. Atomic coordinates ( x 10*) and equivalent isotropic displacement parameters (A2 x 103). U(eq) is. defined as one third of the trace of the orthogonalized Uij tensor. atom X y z Ueq Zr (1) 7571.1(5) 8647.7 (3) 7508.8 (4) 40.8(2) C<1) 6884(8) 8679 (5) 8649 (6) 85 (2) C(2) 5933 (5) 8684 (4) 6253 (5) 71 (2) C(3) 9371 (5) 10123 (4) 7568 (5) 52 (2) N(l) 9456 (4) 8612 (3) 7516 (3) 42 (1) C(4) 10039 (5) 9344 (3) 7539 (4) 48(1) C(5) 11165 (5) 9347 (4) 7546 (5) 67 (2) C(6) 11695 (6) 8588 (4) 7536(6) 74 (2) C(7) 11096 (5) 7825 (4) 7502 (5) 64 (2) C (8) 9979 (5) 7867 (3) 7505(4) 50 (2) C (9) 9229 (5) 7104 (4) 7481 (5) 56 (2) N(2) 8128 (4) 7385 (3) 7535(3) 47 (1) N(3) 8223 (4) 9888 (3) 7558(3) 43 (1) C(10) 7462 (5) 6669 (4) 7662 (4) 46(1) C (11) 7612 (6) 6399(5) 8550 (5) 68 (2) C(12) 6945 (6) 5709(5) 8651 (6) 80 (2) C(13) 6192 (7) 5305(5) 7916 (5) 78 (2) C(14) 6038(6) 5549 (4) 7048 (5) 63 (2) C(15) 6672 (5) 6238 (4) 6904 (4) 53 (2) C(16) 6515 (6) 6468(5) 5924(5) 71 (2) C(17) 5297(7) 6411(6) 5225 (5) 98(3) C(18) 8507(9) 6797(6) 9392(6) 106(3) C(19) 9366 (11) 6222 (7) 9998(8) 177 (7) C(20) 7518(5) 10619 (3) 7540 (4) 45(1) C(21) 6808 (5) 10975(4) 6683(4) 53 (2) C(22) 6072(6) 11651(5) 6677(5) 72 (2) C(23) 6057(7) 11971(5) 7485(5) 79(2) C(24) 6771 (6) 11666(5) 8314(5) 74 (2) C(25) 7520 (5) 10977 (4) 8370 (4) 59 (2) C(26) 6850 (6) 10687(5) 5788 (5) 72 (2) C(27) 7339(8) 11343 (5) 5316 (5) 87 (2) C(28) 8337 (8) 10659 (5) 9299 (5) 86 (3) 288 C(29) 9191(11) 11296(6) 9843(7) 158(5) 289 Table S3. Bond Distances (A) and Angles (°) 2r(l)-N(2) 2. 101(4) Zr(l)-N(3) 2. 104(5) Zr(l)-C(2) 2. 243 (6) Zr(l)-Cd) 2. 248 (7) Zrd)-N(l) 2. 325(4) C(3)-N(3) 1. 461(7) C(3)-C(4) 1. 489(8) N(l)-C(8) 1. 344(6) N(l)-C(4) 1. 354(7) C(4)-C(5) 1. 386(8) C(5)-C(6) 1. 366(8) C(6)-C(7) 1. 403(8) C(7)-C(8) 1. 384 (8) C(8)-C(9) 1. 510(8) C(9)-N(2) 1. 463 (7) N(2)-C(10) 1 453(7) N(3)-C(20) 1 438(7) C(10)-C(15) 1 403 (8) C(10)-C(ll) 1 404(8) C(ll)-C(12) 1 .409 (9) C(ll)-C(18) 1 511 (10) C(12)-C(13) 1 .345(9) C(13)-C(14) 1 360(9) C(14)-C(15) 1 .405(8) C(15)-C(16) 1 .522 (8) C(16)-C(17) 1 .502 (10) C(18)-C(19) 1 .451 (11) C(20)-C(25) 1 .419 (8) C(20)-C(21) 1 .421(8) C(21)-C(22) 1 .399 (9) C"(21)-C(26) 1 .496(8) C(22)-C(23) 1 .373 (9) C(23)-C(24) 1 .362 (9) C(24)-C(25) 1 .408 (9) C(25)-C(28) 1 .519 (9) C(26)-C(27) 1 .522 (9) C(28)-C(29) 1 .478 (11) N(2)-Zr(1)-N(3) 139.6(2) N(3)-Zr(1)-C(2) 102.6(2) N(3)-Zr(l)-C(l) 101.7(2) N(2)-Zr(l)-N(l) 70.0(2) C(2)-Zr(l)-N(l) 125.5(2) N(3)-C(3)-C(4) 109.7(4) C(8)-N(l)-Zr(l) 120.4(4) N(l)-C(4)-C(5) 121.7(5) C(5)-C(4)-C(3) 124.3(5) C(5)-C(6)-C(7) 120.1(6) N(l)-C(8)-C(7) 121.8(5) C(7)-C(8)-C(9) 124.4(5) C(10)-N(2)-C(9) 111.0(4) C(9)-N(2)-Zr(l) 126.2(3) C(20)-N(3)-Zr(l) 121.5(3) C(15)-C(10)-C(ll) 119.4(6) C(ll)-C(10)-N(2) 119.8(5) C(10)-C(ll)-C(18) 121.9(7) N(2)-Zr (l.)-C(2) N(2)-Zr(l)-C(l) C(2)-Zr(l)-C(l) N(3)-Zr(l)-N(l) C(l)-Zr(l)-N(l) C(8)-N(l)-C(4) C(4)-N(l)-Zr(l) N(l)-C(4)-C(3) C(6)-C(5)-C(4) C(8)-C(7)-C(6) K(l)-C(8)-C(9) N(2)-C(9)-C(8) C(10)-N(2)-Zr(l) C(20)-N(3)-C(3) C(3)-N(3)-Zr(l) C(15)-C(10)-N(2) C(10)-C(ll)-C(12) C(12)-C(ll)-C(18) 102.9 (2) 102.9(2) 102.4(3) 69.7 (2) 132.0(3) 119.4 (5) 120.1 (4) 114.0(5) 118.8(6) 118.2(6) 113.7(5) 109.4(4) 122.7(4) 112.0(4) 126.4 (3) 120.7 (5) 118.5(6) 119.5 (7) C(13) -C(12) -C(ll) 121 1(8) C(13) -C(14) -C(15) 120 .0(7) C(10) -C(15) -C(16) 122 .0(6) C(17) -C(16) -C(15) 116 .3(6) C(25) -C(20) -C(21) 120 .2 (5) C(21) -C(20) -N(3) 119 .5(5) C(22) -C<21) -C(26) 118 .2(6) C(23) -C(22) -C(21) 120 .3 (7) C(23) -C(24) -C(25) 120 .7 (7) C(24) -C(25) -C(28) 120 .1(6) C(21) -C(26) -C(27) 114 .2(6) C(12) -C(13) -C(14) 121. 5 (8) C(10) -C(15) -C(14) 119 4(6) C(14) -C(15) -C(16) 118 5(6) C(19) -C(18) -C(ll) 115 .8(8) C(25) -C(20) -N(3) 120 .3,(5) C(22) -C(21) -C(20) 118 .7(6) C(20) -C(21) -C(26) 123 .0(6) C(24) -C(23) -C(22). 121 .9(8) C(24) -C(25) -C(20) 118 .1(6) C(20) -C(25) -C(28) 121 .7(6) C(29) -C(28) -C(25) 114 .2 (7) 291 Table S4. Anisotropic displacement parameters (A2 x 103) . . . .• _ -=-• i - ^^.Tr,ff,T-ih fartn-r PXDOnent ti form atom Ull Zr(l) 42(1) C(l) 116(6) C(2) 51(4) C(3) 48(3) N(l) 40(2) C(4) 37(3) C(5) 48(4) C(6) 46(3) C(7) 52(4) C(8) 45(3) C(9) 56(4) N (2 ) 5 0(3) N(3) 42(3) C(16) 81(5) C(17) 93(6) C(18) 149(9) C(19) 188(13) C(26) 76(5) C(27) 109(6) C{28) 135(7) C(29) 213(14) : -27i2[h2a*2Ull + . . + 2hka*b*U12] U22 U33 U23 U13 U12 31(1) 53 (1) 0(1) 20 (1) 0(1) 65(5) 106 (6) -2(5) 78(6) -6 (5) 54 (4) 92 (5) 2 (4) 7 (3) -1(3) 34 (3) 71 (4) -2 (3) 17 (3) -3(3) 35 (2) 49 (3) 7 (2) 15 (2) 4(2) 40(3) 61 (4) 0 (3) 11 (3) -1 (3) 43 (4) 107(6) -2 (4) 27 (4) -6 (3) 66 (5) 113 (6) -2(5) 33 (4) 11 (4) 47 (4) 93 (5) 7 (4) 27 (4) 10(3) 38(3) 68 (4) 8 (3) 21 (3) 11 (3) 31 (3) 81 (5) 2 (3) 26 (3) 7 (3) 28 (2) 66 (3) 3 (2) 26 (3) 1 (2) 32 (3) 53 (3) -3 (2) 16 (2) 4(2) 64 (5) 75(5) -7 (4) 36(4) -1 (4) . 116 (8) 77 (6) 0(5) 23 (5) -6(6) 75(6) 74 (6) 19 (5) 19 (6) -1(6) 136 (11) 128 (10) 47 (8) -34 (9) -21 (10) . 66(5) 59 (5) 2 (4) 7 (4) -9 (4) 78 (5) 70(5) 16(5) 27 (4) -9 (5) 60 (5) 62 (5) -10(4) 35 (5) -4 (5) 107 (9) 101(8) -33 (7) -6(8) -9 (9) 292 H(29B) H(29C) 9667 (61) 9675 (60) 11474 (49) 11051(22) 9512(32) 10418(30) 238 238 Table S6. Selected torsion angles 2. 02 (43) N2- Zrl-Nl-C8 -89. 80(48) C2- Zrl-Nl-C8 -177 . 48 (46) N2- Zrl-Nl-C4 90. 69 (47) C2- Zrl-Nl-C4 0. 41(87) C8- N1-C4-C5 -178. 90(55) C8- N1-C4-C3 -0. 32(73) N3- C3-C4-N1 -0. 5(1.0) Nl-•C4-C5-C6 1. 2(1.1) C4-•C5-C6-C7 -1. 01(91) C4-•N1-C8-C7 179 . 67(55) C4--N1-C8-C9 1. 6(1.0) C6--C7-C8-N1 -3 51 (77) Nl--C8-C9-N2 -170 91 (49) C8--C9-N2-C10 167 74(38) N3--Zrl-N2-C10 41 .76 (49) Cl--Zrl-N2-C10 -8 .87(64) N3--Zrl-N2-C9 -134 .84 (55) Cl -Zrl-N2-C9 -177 .16(50) C4 -C3-N3-C20 -178 .53 (40) N2 -Zrl-N3-C20 -52 .21 (49) Cl -Zrl-N3-C20 4 .70(60) N2 -Zrl-N3-C3 131 .02 (52) Cl -Zrl-N3-C3 -89 .33(66) C9 -N2-C10-C15 90 .28(68) C9 -N2-C10-C11 90 .75 (59) Zrl-N3-C20-C25 179.00(47) N3-Zrl-Nl-C8 91.46(52) Cl-Zrl-Nl-C8 -0.51(41) N3-Zrl-Nl-C4 -88.05(49) Cl-Zrl-Nl-C4 179.92(50) Zrl-Nl-C4-C5 0.61(67) Zrl-Nl-C4-C3 -179.61(62) N3-C3-C4-C5 178.72(68) C3-C4-C5-C6 -1.7(1.1) C5-C6-C7-C8 179.48(51) Zrl-Nl-C8-C7 0.36(70) Zrl-Nl-C8-C9 -179.31(67) C6-C7-C8-C9 177.39(64) C7-C8-C9-N2 6. 04 (76) C8-C9-N2-Zrl -64.45(47) C2-Zrl-N2-C10 172.11(47) Nl-Zrl-N2-C10 118.95(53) C2-Zrl-N2-C9 -4.50(49) Nl-Zrl-N2-C9 -0.13(72) C4-C3-N3-Zrl 53.55(47) C2-Zrl-N3-C20 177.09(46) Nl-Zrl-N3-C20 -123.22(50) C2-Zrl-N3-C3 0.32(46) Nl-Zrl-N3-C3 93.60(60) Zrl-N2-C10-C15 -86.79(62) Zrl-N2-C10-Cll -88.47(58) Zrl-N3-C20-C21 Table Sl. Least-squares planes (x,y,z in crystal coordinates) and deviations from them (* indicates atom used to define plane) 0.036(27) x - 0.134(29) y + 14.570(13) z = 10.885(28) -0.033 (0.002) Zrl * -0.015 (0.001) NI 0.024 (0.002) N2 * 0.024 (0.002) N3 1.625 (0.010) Cl -1.869 (0.009) C2 Rms deviation of fitted atoms = 0.025 0.298(24) x + 15.756(3) y - 0.258(67) z = 13.657(057) Angle to previous plane (with approximate esd) = 89.05(28) * 0.000 (0.000) Zrl 0.000 (0.000) Cl -1.974 (0.005) N2 Rms deviation of fitted * 0.000 (0.000) Nl 0.040 (0.012) C2 1.972 (0.005) N3 atoms = 0.000 - 0.095(34) x - 0.380(46) y + Angle to previous plane (with * -0.001 (0.004) Nl * -0.002 (0.005) C5 * -0.008 (0.005) C7 0.018 (0.011) C3 Rms deviation of fitted atoms 14.627(16) 2 = 10.578(47) approximate esd) = 88.14(31) * -0.001 (0.005) C4 * 0.007 (0.005) C6 * 0.005 (0.005) C8 0.007 (0.011) C9 0.005 - 9.646(21) x - 9.848(34) y - 4.507(42) z = 2.818(42) Angle to previous plane (with approximate esd) = 89.37(23) 0.004 (0.004) 0.004 (0.005) C10 C12 •0.001 (0 . 005) C14 •0.063 (0.011) C16 •0.096 (0.014) C18 -0.006 (0.005) 0.000 (0.005) Cll C13 -0.001 (0.004) C15 0.741 (0.014) C17 -1.220 (0.018) C19 Rms deviation of fitted atoms = 0. 003 9.482 (22) x + 10.096 (33)' y -Angle to previous plane (with * -0.019 (0.004) C20 0.003 (0.005) C22 * 0.014 (0.005) C24 0.129 (0.011) C26 0.081 (0.012) C28 4.075(41) z = 14.796 (42) approximate esd) = 78.52(16) 0.016 (0.004) C21 * -0.018 (0.005) C23 0.005 (0.005) C25 1.448 (0.012) C27 1.312 (0.016) C29 Rms deviation of fitted atoms = 0.014 295 296 Table 1. Crystal data and structure refinement for [Zr(L)(HNtBu)]. Identification code Empirical formula Formula weight Temperature Wavelength Crystal system Space group Unit cell dimensions Volume Z Density (caJculaied) Absorption coefficient F(000) Crystal size Theta ranee for data collection Limiting indices Reflections collected Independent reflections Refinement method Data / restraints / parameters Goodness-of-fit on F2 Final R indices (I>2sigma(I)) R indices (all data) Largest diff. peak and hole DM01 C35HsoN4Zr 618.01 293(2)K 0.71073 A Orthorhombic Pna2, (No. 33) a = 29.5757(6) A b = 20.0757(4) A c= 11.7560(1) 6980.2(2) A3 8 1.176 g/cnr 0.342 mm'1 2624 0.15 x 0.20x 0.20 mm 1.2 to 22.5 deg -39 < h < 27, -26 < k < 26, -14 < / < 15 27501 8679 (R(int) = 0.0481) Full-matrix least-squares on F2 8668 / 1 /716 1.064 R, = 0.0734, wR2 = 0.1640 R, =0.1027, wR2 = 0.1844 0.911 and -0.764 e/A3 Table 2. Atomic coordinates (x 104) and equivalent isotropic displacement parameters (A2 x 103) for DM01. Atom x y z U(eq) Zr(l) 6142(1) 6472(1) 9090(1) 62(1) Zr(2) 3714(1) 8843(1) -14069(1) 102(1) N(l) 6044(3) 7351(4) 7788(7) 68(2) N(2) 5848(3) 6117(3) 7575(7) 65(2) N(3) 6414(3) 7352(4) 9756(7) 78(3) N(4) 653 7(4) 5659(6) 9514(9) 121(4) N(5) 3615(3) 9732(4) -12843(8) 68(2) N(6) 3464(4) 8497(4) -12514(8) 100(3) N(7) 3919(4) 9713(4) -14844(9) 89(3) N(8) 3955(7) 8055(8) -14713(15) 209(8) C(l) 6191(4) 7959(5) 8090(10) 83(3) C(2) 6122(5) 8492(6) 7349(12) 108(4) C(3) 5919(5) 8382(6) 6325(11) 101(4) C(4) 5770(5) 7757(6) 6077(11) 104(4) C(5) 5833(4) 7246(5) 6782(9) 63(3) C(6) 5688(4) 6538(5) 6631(9) 78(3) C(7) 6400(4) 8015(5) 9255(11) 91(3) C(8) 5813(4) 5422(4) 7274(8) 65(3) C(9) 6157(3) 5128(5) 6626(9) 67(3) C(10) 6552(5) 5496(6) 6154(11) 95(4) COD 6527(5) 5550(8) 4835(12) 128(5) C(12) 7008(4) 5240(8) 6559(14) 135(6) C(13) 6117(4) 4447(6) 6391(10) 89(3) C(14) 5755(5) 4086(6) 6804(11) 93(4) C(15) 5432(4) 4373(5) 7404(10) 88(3) C(16) 5441(4) 5040(5) 7685(10) 74(3) C(17) 5054(4) 5347(7) 8401(11) 99(4) C(18) 4975(6) 4919(11) 9469(13) 169(8) C(19j 4624(5) 5377(8) 7713(17) 160(7) C(20) 6482(4) 7356(4) 10958(11) 66(3) C(21) 6914(4) 7463(5) 11429(11) 80(3) C(22) 7320(4) 7641(6) 10644(12) 99(4) C(23) 7476(5) 8354(6) 10838(14) 135(5) C(24) 7728(6) 7156(9) 10839(18) 168(7) C(25) 6981(4) 7422(6) 12607(12) 86(3) C(26) 6628(4) 7284(6) 13292(11) 91(4) C(27) 6204(4) 7173(6) 12847(12) • 95(4) C(28) 6119(4) 7211(5) 11679(11) 73(3) C(29) 5646(5) 7154(8) 11197(13) 118(5) C(30) 5304(6) 7350(15) 11814(32) 415(32) C(31) 5608(4) 6503(6) 10473(11) 94(4) C(32) 6716(4) 5232(5) 10314(10) 80(3) C(33) 6646(6) 5491(10) 1 1558(13) 146(6) C(34) 7165(5) 5048(10) 10024(15) 180(9) C(35) 6443(9) 4620(10) 10225(23) 244(13) C(36) 3702(4) 10359(6) -13197(9) 87(4) C(37) 3631(4) 10911(5) -12544(10) 90(3) C(38) 3435(4) 10813(6) -11496(11) 92(4) C(39) 3330(4) 10186(6) -11098(11) 96(4) C(40) 3419(4) 9654(5) -11842(12) 81(3) C(41) 3310(6) 8930(6) -11568(12) 143(7) C(42) 3913(6) 10373(6) -14355(11) 132(6) C(43) 3412(4) 7812(5) -12244(10) 78(3) C(44) 3744(4) 7484(5) -11596(10) 75(3) C(45) 4158(5) 7860(7) -11171(11) 106(4) C(46) 4596(5) 7505(10) -11581(16) 160(7) C(47) 4152(5) 7867(8) -9839(13) 134(5) C(48) 3688(5) 6830(6) -11368(11) 93(4) C(49) 3320(5) 6478(6) -11716(11) 97(4) C(50) 2988(4) 6809(6) -12358(10) 94(4) C(51) 3029(4) 7475(5) -12610(10) 82(3) C(52) 2665(5) 7830(11) -13269(14) 165(9) C(53) 2228(5) 7875(11) -12674(20) 202(10) C(54) 2540(8) 7409(14) -14443(18) 242(14) C(55) 3963(5) 9720(5) -16109(9) 74(3) C(56) 4396(5) 9773(6) -16576(11) 93(4) C(57) 4825(4) 9898(7) -15929(16) 112(4) C(58) 4981(6) 10616(8) -16054(20) 196(9) C(59) 5183(5) 9424(10) -16214(18) 182(9) C(60) 4404(5) 9755(6) -17767(13) 97(4) C(61) 4021(5) 9657(6) -18413(11) 93(4) C(62) 3620(4) . 9612(5) -17904(10) 80(3) C(63) 3561(5) 9647(6) -16759(11) 85(3) C(64) 3081(5) 9612(8) -16234(14) 132(6) C(65) 2774(6) 10070(17) -16709(19) 280(16) C(66) 3025(8) 8985(12) -15490(22) 237(11) C(67) 4103(8) 7571(6) -15531(16) 168(9) C(68) 4188(12) 7899(14) -16555(21) 300(20) C(69) 4500(13) 7209(21) -15170(24) 441(38) C(70) 3772(15) 7059(13) -15542(49) 580(55) Table 3. Bond lengths (A) and angles (deg) for DM01. Zr(l)-N(4) 2.036(9) Zr(l)-N(3) 2.093(8) Zr(l)-N(2) 2.106(7) Zr(l)-C(31) 2.268(12) Zr(l)-N(l) 2.352(8) Zr(2)-N(8) 1.893(12) Zr(2)-N(7) 2.061(9) Zr(2)-N(6) 2.090(8) Zr(2)-N(5) 2.313(9) Zr(2)-C(66) 2.65(2) N(D-C(1) 1.343(12) N(1>C(5) 1.354(12) N(2)-C(8) 1.443(1 1) N(2)-C(6) 1.473(12) N(3)-C(20) 1.428(14) N(3)-C(7) 1.456(12) N(4)-C(32) 1.401(14) N(5)-C(40) 1.320(14) N(5)-C(36) 1.350(14) N(6)-C(43) 1.420(12) N(6)-C(41) 1.49(2) N(7)-C(42) 1.44(2) N(7)-C(55) 1.49(2) N(8)-C(67) 1.44(2) C(l)-C(2) 1.39(2) C(l)-C(7) 1.51(2) C(2)-C(3) 1.36(2) C(3)-C(4) 1.36(2) C(4)-C(5) 1.333(14) C(5)-C(6) 1.494(14) C(8)-C(9) 1.401(13) C(8)-C(16) 1.425(14) C(9)-C(13) 1.40(2) C(9)-C(10) 1.49(2) C(10)-C(12) 1.52(2) C(10)-C(ll) 1.56(2) C(13)-C(14) 1.38(2) C(14)-C(15) 1.32(2) C(15)-C(16) 1.381(14) C(16)-C(17) 1.55(2) C(17)-C(19) 1.51(2) C(17)-C(18) 1.54(2) C(20)-C(28) 1.40(2) C(20)-C(21) 1.41(2) C(21)-C(25) 1.40(2) C(21)-C(22) 1.55(2) C(22>C(23) 1.52(2) C(22)-C(24) 1.57(2) C(25)-C(26) 1.35(2) C(26)-C(27) 1.38(2) C(27)-C(28) 1.40(2) C(28)-C(29) 1.51(2) C(29)-C(30) 1.30(3) C(29)-C(31) 1.56(2) C(32)-C(34) 1.42(2) C(32)-C(35) 1.47(2) C(32)-C(33) 1.57(2) C(36)-C(37) 1.36(2) C(36)-C(42) 1.50(2) C(37)-C(38) 1.38(2) C(38)-C(39) 1.38(2) C(39)-C(40) 1.40(2) C(40)-C(41) 1.52(2) C(43)-C(5]) 1.39(2) C(43)-C(44) 1.41(2) C(44)-C(48) 1.35(2) C(44)-C(45) 1.52(2) C(45)-C(46) 1.55(2) C(45)-C(47) 1.57(2) C(48)-C(49) 1.36(2) C(49)-C(50) 1.40(2) C(50)-C(51) 1.38(2) C(51)-C(52) 1.51(2) C(52)-C(53) 1.47(2) C(52)-C(54) 1.66(3) C(55)-C(56) 1.40(2) C(55)-C(63) 1.42(2) C(56)-C(60) 1.40(2) C(56)-C(57) 1.50(2) C(57>C(59) 1.46(2) C(57)-C(58) 1.52(2) C(60)-C(61) 1.38(2) C(61)-C(62) 1.33(2) C(62)-C(63) 1.36(2) C(63)-C(64) 1.55(2) C(64)-C(65) 1.41(2) C(64)-C(66) 1.54(2) C(67)-C(68) 1.39(3) C(67)-C(70) C(67)-C(69) 1.42(3) 1.44(3) N(4)-Zr(l)-N(3) 112.0(4) N(4)-Zr(l)-N(2) 99.3(4) N(3)-Zr(l)-N(2) 139.6(3) N(4)-Zr(l)-C(31) 103.1(4) N(3)-Zr(l)-C(31) 88.7(4) N(2)-Zr(l)-C(31) 109.1(4) N(4)-Zr(l)-N(l) 145.8(4) N(3)-Zr(l)-N(l) 70.0(3) N(2)-Zr(l)-N(l) 69.7(3) C(31)-ZT(1)-N(1) 111.1(4) N(8)-Zr(2)-N(7) 114.9(6) N(8)-Zr(2)-N(6) 101.8(6) N(7)-Zr(2)-N(6) 140.6(4) N(8)-Zr(2)-N(5) 160.4(7) N(7)-Zr(2)-N(5) 70.0(3) N(6)-Zr(2)-N(5) 70.5(3) N(8)-Zr(2)-C(66) 97.3(9) N(7)-Zr(2)-C(66) 81.8(6) N(6)-Zr(2)-C(66) 108.3(7) N(5)-Zr(2)-C(66) 102.2(6) C(l)-N(l)-C(5) 121.5(9) C(l)-N(l)-Zr(l) 118.0(7) C(5)-N(l)-Zr(l) 120.5(7) C(8)-N(2)-C(6) 110.3(7) C(8)-N(2)-Zr(l) 124.3(6) C(6)-N(2)-Zr(l) 125.1(6) C(20)-N(3)-C(7) 113.5(8) C(20)-N(3)-Zr(l) 115.5(6) C(7)-N(3)-Zr(l) 127.5(7) C(32)-N(4)-Zr(l) 152.1(9) C(40)-N(5)-C(36) 118.0(9) C(40)-N(5)-Zr(2) 121.3(7) C(36)-N(5)-Zr(2) 120.2(8) C(43)-N(6)-C(41) 111.4(8) C(43)-N(6)-Zr(2) 123.8(7) C(41)-N(6)-Zr(2) 124.7(7) C(42)-N(7)-C(55) 112.9(9) C(42)-N(7)-Zr(2) 126.7(8) C(55)-N(7)-Zr(2) 118.3(7) C(67)-N(8)-Zr(2) 162(2) N(l)-C(l)-C(2) 119.0(11) N(l)-C(l)-C(7) 116.2(9) C(2)-C(l)-C(7) 124.8(10) C(3)-C(2)-C(l) 119.5(11) C(4)-C(3)-C(2) 118.8(11) C(5)-C(4)-C(3) 122.1(12) C(4)-C(5)-N(l) 119.1(10) C(4)-C(5)-C(6) 128.2(11) N(D-C(5)-C(6) 112.7(9) N(2)-C(6)-C(5) 111.3(8) N(3)-C(7)-C(l) 108.1(8) C(9)-C(8)-C(16) 121.2(9) C(9)-C(8)-N(2) 119.3(9) C(16)-C(8)-N(2) 119.4(9) C(13)-C(9)-C(8) 117.2(10) C(13)-C(9)-C(10) 118.5(10) C(8)-C(9)-C(10) 124.3(10) C(9)-C(10)-C(12) 114.3(11) C(9)-C(10)-C(ll) 111.7(11) C(12)-C(10)-C(ll) 112.2(12) C(14)-C(13)-C(9) 120.6(11) C(15)-C(14)-C(13) 121.4(11) C(14)-C(15)-C(16) 122.5(11) C(15)-C(16)-C(8) 117.2(10) C(15)-C(16)-C(17) 120.1(11) C(8)-C(16)-C(17) 122.7(10) C(19>C(17)-C(18) 109.3(12) C(19)-C(17)-C(16) 110.4(11) C(18)-C(17)-C(16) 109.5(12) C(28)-C(20)-C(21) 119.3(12) C(28)-C(20)-N(3) 119.3(10) C(21)-C(20)-N(3) 121.2(11) C(25)-C(21)-C(20) 120.4(12) C(25)-C(21)-C(22) 119.5(11) C(20)-C(21)-C(22) 120.0(11) C(23)-C(22)-C(21) 111.1(11) C(23)-C(22)-C(24) 109.1(12) C(21)-C(22)-C(24) 111.4(11) C(26)-C(25)-C(21) 119.7(11) C(25)-C(26)-C(27) 120.8(12) C(26)-C(27)-C(28) 121.9(12) C(27)-C(28)-C(20) 117.9(11) C(27)-C(28)-C(29) 122.0(12) C(20)-C(28)-C(29) 119.9(12) C(30)-C(29)-C(28) 119(2) C(30)-C(29)-C(31) 120(2) C(28)-C(29)-C(31) 109.4(11) C(29)-C(31)-Zr(l) 111.3(8) N(4)-C(32)-C(34) 113.0(12) N(4)-C(32)-C(35) 103.6(13) C(34)-C(32)-C(35) 106(2) N(4)-C(32)-C(33) 111.6(11) C(34)-C(32)-C(33) 115.6(12) C(35)-C(32>C(33) 106(2) N(5)-C(36)-C(37) 123.6(11) N(5)-C(36)-C(42) 112.1(10) C(37)-C(36)-C(42) 124.2(11) C(36)-C(37)-C(38) 117.0(11) C(39)-C(38)-C(37) 121.9(11) C(38)-C(39)-C(40) 116.1(11) N(5)-C(40)-C(39) 123.2(10) N(5)-C(40)-C(41) 113.3(10) C(39>C(40)-C(41) 123.5(12) N(6)-C(41)-C(40) 109.5(10) N(7)-C(42)-C(36) 110.6(10) C(51)-C(43)-C(44) 120.6(9) C(51)-C(43)-N(6) 119.5(11) C(44)-C(43)-N(6) 119.8(11) C(48)-C(44)-C(43) 118.3(11) C(48)-C(44)-C(45) 121.1(12) C(43)-C(44)-C(45) 120.6(10) C(44)-C(45)-C(46) 109.9(11) C(44)-C(45)-C(47) 108.9(12) C(46)-C(45)-C(47) 108.9(13) C(44)-C(48)-C(49) 123.0(12) C(48>C(49)-C(50) 118.4(11) C(51)-C(50)-C(49) 120.9(12) C(50)-C(51)-C(43) 118.7(11) C(50)-C(51)-C(52) 120.5(14) C(43)-C(51)-C(52) 120.8(12) C(53)-C(52)-C(51) 114.3(13) C(53)-C(52)-C(54) 103(2) C(51)-C(52)-C(54) 110(2) C(56)-C(55)-C(63) 124.3(11) C(56)-C(55)-N(7) 118.1(12) C(63)-C(55)-N(7) 117.6(11) C(60)-C(56)-C(55) 113.9(12) C(60)-C(56)-C(57) 120.0(14) C(55)-C(56)-C(57) 126.0(13) C(59)-C(57)-C(56) 112.7(14) C(59)-C(57)-C(58) 112.0(14) C(56)-C(57)-C(58) 111.5(11) C(61)-C(60)-C(56) 122.9(12) C(62)-C(61)-C(60) 119.6(12) C(61)-C(62)-C(63) 123.7(12) C(62)-C(63)-C(55) 115.6(11) C(62)-C(63)-C(64) 120.6(13) C(55)-C(63)-C(64) 123.8(12) C(65)-C(64)-C(66) 134(2) C(65)-C(64)-C(63) 113.7(14) C(66)-C(64)-C(63) 111.2(14) C(64)-C(66)-Zr(2) 111.3(13) C(68)-C(67)-C(70) 117(3) C(68)-C(67)-N(8) 108.3(14) C(70)-C(67)-N(8) 106(2) C(68)-C(67)-C(69) 110(2) C(70)-C(67)-C(69) 102(3) N(8)-C(67)-C(69) 113(2) 308 Table 4. Anisotropic displacement parameters (A x 10 ) for DM01. Atom Ul 1 U22 U33 U23 U13 U12 Zr(l) 82(1) 47(1) 58(1) -6(1) -9(1) -1(1) Zr(2) 184(1) 46(1) 77(1) 5(1) 31(1) 0(1) N(l) 92(6) 53(5) 60(6) -2(4) -8(5) 7(4) N(2) 76(6) 50(4) 70(6) -14(4) -25(4) 6(4) N(3) 129(8) 50(5) 56(6) -6(4) -31(5) -21(5) N(4) 132(9) 134(9) 96(8) 23(7) 10(6) 67(7) N(5) 80(6) 47(5) 77(7) 14(4) 5(5) -2(4) N(6) 171(10) 53(5) 76(7) 20(5) 39(6) -4(5) N(7) 150(9) 46(5) 69(7) 4(5) 14(6) -1(5) N(8) 335(22) 129(12) 164(14) -33(11) 86(15) 81(13) C(l) 140(10) . 41(6) 70(7) 1(5) -17(7) -6(6) C(2) 169(13) 51(6) 103(10) 8(7) -17(9) 0(7) C(3) 156(11) 64(8) 82(9) 14(6) -10(8) 7(7) C(4) 157(12) 78(8) 76(9) -2(7) -18(8) 23(7) C(5) 75(8) 63(7) 53(7) -1(5) -2(5) 16(5) C(6) 90(8) 66(7) 78(8) -16(6) -32(6) 5(6) C(7) 136(9) 62(7) 77(9) 4(6) -17(8) -24(6) C(8) 88(8) 55(6) 50(6) -5(5) -5(5) 9(5) C(9) 78(7) 56(6) 68(7) -6(5) 5(6) -8(5) C(10) 113(10) 80(8) 92(11) -16(7) 18(8) -11(7) C(ll) 164(14) 124(12) 96(11) 4(9) 44(9) -9(10) C(12) 75(9) 183(16) 146(14) 9(H) 28(9) -1(9) C(13) 114(9) 68(7) 85(8) -18(6) 4(7) 3(7) C(14) 129(11) 51(7) 99(10) -7(6) 4(8) -10(7) C(15) 120(10) 58(7) 86(9) 2(6) -8(7) -28(7) C(16) 81(8) 82(8) 61(7) -8(6) -6(6) -8(6) C(17) 78(8) 129(11) 90(10) -40(8) 12(7) -27(7) C(18) 176(16) 249(21) 82(13) -12(12) 32(10) -50(15) C(19) 100(11) 176(16) 203(19) -61(14) -23(12) 11(10) C(20) 72(7) 52(5) 74(7) -14(6) -15(6) -8(5) C(21) 109(10) 57(7) 75(9) -8(5) -7(7) 1(6) C(22) 100(9) 98(9) 100(11) 0(7) -3(7) -15(8) C(23) 134(11) 130(11) 140(13) -6(11) 36(10) -55(9) C(24) 140(14) 177(16) 187(19) -5(16) 71(14) 3(12) C(25) 76(8) 100(9) 83(10) -15(7) -10(7) -6(6) C(26) 90(9) 118(10) 67(8) -7(7) -25(7) -16(7) C(27) 98(10) 100(10) 88(10) 4(8) 13(8) -12(7) C(28) 67(7) 62(7) 89(9) -14(6) -13(7) -12(6) C(29) 92(10) 148(13) 115(12) -65(10) -8(8) -2(9) C(30) 100(14) 440(43) 706(70) -467(49) -127(25) 97(19) C(31) 86(8) 101(9) 95(9) -17(7) -18(6) 5(7) C(32) 100(9) 65(7) 74(8) 4(6) -22(6) 4(6) C(33) 152(14) 204(18) 83(11) 7(11) -24(10) 27(13) C(34) 120(12) 270(24) 150(17) 52(16) -17(11) 97(14) C(35) 359(33) 130(17) 244(28) -9(16) -57(26) -86(20) C(36) 135(10) 65(8) 60(8) 3(6) -2(7) 3(6) C(37) 152(11) 56(6) 62(8) -3(6) -2(7) -7(7) C(38) 121(10) 68(8) 88(9) -7(6) -8(7) 15(7) C(39) 146(10) 76(8) 65(8) 4(7) 28(8) 26(7) C(40) 85(8) 62(7) 97(9) 10(7) 8(7) 10(6) C(41) 260(20) 78(9) 92(10) 16(8) 62(11) 18(10) C(42) 261(18) 57(8) 77(10) 12(6) 48(10) -9(9) C(43) 115(10) 46(6) 74(8) 6(5) 14(7) 6(6) C(44) 102(9) 60(7) 64(7) 12(5) 22(6) 0(6) C(45) 122(10) 100(9) 95(12) -4(8) -14(8) -26(8) C(46) 145(14) 184(17) 150(15) -42(13) 20(12) -32(13) C(47) 155(14) 151(14) 97(11) -14(10) -29(10) 11(11) C(48) 114(10) 75(9) 91(10) 16(7) 10(7) 15(7) C(49) 132(11) 60(7) 99(9) 12(7) 19(8) 2(8) C(50) 109(10) 90(9) 83(9) -2(7) -2(7) -16(7) C(51) 107(9) 70(8) 70(8) 23(6) -5(7) 1(7) C(52) 103(12) 262(23) 128(15) 106(16) 39(10) 49(13) C(53) 104(13) 269(24) 232(22) 95(20) -1(14) 74(14) C(54) 252(25) 359(38) 115(18) -3(18) -92(18) 3(22) C(55) 128(10) 42(5) 53(9) 16(5) 18(8) -2(5) C(56) 128(12) 70(7) 80(9) 22(6) 0(9) -14(7) C(57) 88(8) 139(11) 108(10) 25(11) -31(10) -18(8) C(58) 176(15) 167(15) 245(22) 87(17) -102(17) -86(12) C(59) 117(12) 225(19) 203(22) 48(17) -21(13) 52(13) C(60) 89(9) 100(9) 102(11) 15(8) 26(8) 0(7) C(61) 123(11) 92(9) 65(8) -10(7) 16(9) -3(8) C(62) 84(9) 86(8) 69(9) -2(6) -3(7) -10(6) C(63) 111(10) 82(8) 61(8) 16(6) 22(7) -2(7) C(64) 90(9) 162(13) 143(16) 65(11) 39(9) -9(9) C(65) 92(13) 570(50) 178(20) 35(27) -12(13) 82(22) C(67) 301(24) 48(7) 155(18) 8(8) 136(17) 33(10) C(68) 517(53) 222(28) 163(22) 37(20) 160(29) 155(32) C(69) 544(62) 588(68) 193(28) -142(35) -83(34) 468(62) C(70) 679(83) 121(21) 940(126) -97(42) 557(91) -129(34) 6 Crystallographic data for (BDPP)Zr(CH2Ph)2. 311 312 Table Sl. Crystal Data and Experimental Details. Empirical formula Formula weight Temperature Wavelength Crystal system Space group Unit cell dimensions Volume Z Density, calcd. Absorption coefficient F (0 0 0 } Reflections Collected Independent reflections Refinement method Data/parameters Goodness-of-fit (GooF) on F2 Final R indices [I>2sigma(I)] R indices (all data) C45H55N3Ti ? ? ? ? ? 25°C 0.71073 A Monoclinic P2i/n a = 12.535 (11)A b = 21.683 (21)A c = 14.543 (18)A (3 = 90. 28 (1) 0 3952(7) A3 4 1.223 g.cm"3 0. 311 mm"1 1544 3654 989 [R(int) = 0.0358] Full-matrix least - squares on F 989/ 156 1. 62 R = 0.0972, wR = 0.1077 R = 0.4474, wR2 = 0.3065 R = I(||F0|-|FC1)/E|F0| ; wR = [zVw(F0 " FJ/E/WFJ 313 Table S2. Atomic coordinates ( x 104) and equivalent isotropic displacement parameters (A2 x 103) . U(eq) is defined as one third of the trace of the orthogonalized Uij tensor. atom X y z Ueq Zr (1) 4123 (2) 1476(1) 2508 (3) 44 (1) N(2) 4146 (15) 1136 (12) 1139(18) 44 (7) N(3) 4164 (16) 1132 (12) 3846 (20) 55 (8) N(l) 5019 (15) 555 (12) 2546 (21) 37 (7) C(l) 5293 (21) 363 (16) 1660 (27) 50 (10) C(2) 5985 (24) -209 (18) 1688 (35) 86 (13) C(3) 6334 (24) -411 (19) 2491 (31) 81 (13) C(4) 5993 (25) -201 (18) 3331 (33) 86 (13) C(5) 5369 (23) 338 (16) 3302 (30) 60(10) C (6) 4854 (26) 582 (18) 4079 (32) 88 (13) C (7). 4883 (24 ) 624 (18) 935 (30) 78(12) C (8) 2370 (17) 1895 (11) 2508 (22) 34 (8) CO) 5587 (15) 2115 (12) 2519 (22) 38 (9) C(12) 32 90 (14) 2780(11) 1672(15) 81(12) C(13) 3866 (14) 3330 (11) 1698 (15) 82 (12) C(14 ) 4148 (14) 3592 (11) 2541(15) 99(11) C (15 ) 3E53 (14) 3304 (11) • 3358 (15) 111(15) C(15) 3277 (14) 2753 (11) 3333 (15) 80(12) C (11) 2996 (14) 2491 (11) 2490 (15) 73(11) C(22) 7052 (16) 1609(10) 1654 (15) 90 (12) C(23) • 7930 (16) 1213 (10) 1652 (15) 128(17) C (24 ) 6374 (16) 1015 (10) 2482 (15) 102 (13) C(25) 7941(16) 1212 (10) 3314 (15) 121 (16) C(26) 7063(16) 1607(10) 3315 (15) 77(11) C(21) 6618(16) 1806 (10) 2485 (15) 45 (9) C(32) 3808(10) 1691 (8) -251 (14) 72 (11) C(33) 3161(10) 1828 (8) -1007 (14) 60 (10) C(34) 2158 (10) 1553 (8) -1092 (14) 75 (10) C(35) 1S04 (10) 1143 (8) -422 (14) 58 (10) C(36) 2451 (10) 1006 (8) 334 (14) 68 (11) C(31) 3454(10) 1280 (8) 419 (14) 37 (8) C(42) 2454(11) 990(6) 4685 (13) 43 (9) C(43) 1.6 0 0 (11) 1140 (8) 5425 (13) 57 (10) C (44) 2141 (11) 1569 (8) 6077 (13) 67 (10) C (45) 3137 (11) 1850 (8) 5988 (13) 96 (13) C(46) 3791 (11) 1700 (8) 5247 (13) 66 (11) C (41) 3449 (11) 1271 (8) 4596 (13) 42 (9) C (37) 4949 (11) 1954 (9) -267 (15) 129 (17) C{38) 5607 (17) 1618 (12) -1007(24) . 97 (13) C(39) 4906 (22) 2648 (9) -492 (32) 149 (18) C(40) 2120 (14) 516 (10) 1043 (16) 74 (11) C (27) 2397 (25) -132 (9) 679 (32) 168 (21) C(26) 910 (18) 558 (13) 1213 (28) 101 (14) C(47) 2098 (13) 505 (10) 3972 (14) 69 (11) C(48) 905(17) 592 (14) 3749 (22) 103 (14) C(49) 2282 (26) -146 (9) 4364 (30) 211 (27) C(50) 4940 (12) 1953 (9) 5268 (15) 87 (12) C(51) 5577 (17) 1632 (13) 6040 (23) 119 (15) C(52) 4917 (21) 2653 (9) 5444 (29) 162 (20) Table S3. Bond Distances (A) Zr (1) -N (2) 2 . 124 (26) Zr (1) -N (1) 2 . 293 (24) Zr (1) -C(9). 2 .298 (22) N(2) - C(7) 1 .474 (43) N(3) - C(6) 1 . 510 (45) N(l) - C(l) 1 .397 (49) C (1) - C(2) • 1 .514 (48) C(2) - C(3) 1 . 321 (64 ) C(4) - C(5) 1 .406 (49) C(B) - C(ll) 1 . 513 (32) C(32) -C (37) 1 . 540 (20) C(42) -C(47) 1 . 541 (27) C(37) -C (38) 1 . 542 (36) C (40) -C (27) 1 . 540 (33) C(47) -C (48) 1 .54 0 (27) C(50) -C(51) 1 .541 (35) and Angles ( 0 ) . Zr (1) -N(3) 2 084 (29) Zr (10 -C(8) 2 377 (22) Zr (1) -C(ll) 2 616 (22) N (2) - C(31) 1 392 (29) N(3) - C(41) 1 445 (31) N (1) - C(5) 1 272 (50) C(l) - C(7) 1 301 (55) C(3) - C(4) 1 373 (63) C(5) - C(6) 1 409 (58) C(9) - C (21) 1 458 (30) C(36) -C(40) 1 539 (28) C(46) -C(50) 1 540 (21) C (37) -C(39) 1 541 (30) C (40) -C(28) 1 541 (29) C(47) -C(49) 1 540 (32) C(50) -C(52) 1 540 (28) N(2) - Zr (1) -N(3) 138. 6 (10) N(3) - Zr (1) -N(l) 69 . 9 (10) N(3) - Zr (1) -C(8) 98. 9 (10) N(2) - Zr (1) -C(9) 101. 6 (10) N(l) - Zr (1) -C(9) 97. 7 (8) N(2) - Zr (1) -CUD 107. 0 (8) N(l) - Zr (1) -CUD 176 . 5 (7) C(9) - Zr (1) -CUD 85 . 7 (8) Zr (1) -N(2) -COD 128 . 0 (16) Zr (1) -N(3) -C(6) 120. 2 (23) C(6) - N(3) - C (41) 110 . 6 (25) N(2) - Zr (1) -N(l) 73 .2 (10) N(2) - Zr (1) -C(8) 98 .6(9) NU) - Zr (1) -C(8) 141 .7(8) N(3) - Zr (1) -CO) 101 .2(10) C(8)- Zr (1) -CO) 120 .5(8) N(3) - Zr (1) -CUD 108 .7(8) C(8) - Zr (1) -CUD 34 .9 (7) Zr (1) -N(2) -C(7) 117 .4 (21) C(7) - N(2) - C(31) 114 . 0 (25) Zr (1) -N(3) -C(41) 128 .1 (16) Zr (1) -N(l) -CU) 111 .1 (21) 315 Zr (1) -N(1)-C(5) 120 . 6 (24) C(l) - N(l) -C(5) 127. 0 (27) N(l) - C(l) -C(2) Ill . 3 (32) N(l) - C(l) -C(7) 121 . 3 (30) C(2) - C(l) -C(7) 127 . 0 (38) C(l) - C(2) -C(3) 118 . 8 (40) C(2) - C(3) -C(4) 125 . 0 (36) C(3) - C(4) -C(5) 115. 1 (40) N(l) - C(5) -C(4) 121. 5 (38) N(l) - C(5) -C(6) 113 . 4 (30) C(4) - C(5) -C(6) 123 . 0 (39) N(3) - C(6) -C(5) 112 . 4 (35) N(2) - C(7) -C(l) 114 . 3 (35) Zr (1) -C(8) -C(ll) 81 . 2 (11) Zr (1) -CO) -C (21) 115 . 5 (17) Zr (1) -C(ll) -C(B) 63 . 9 (11) Zr (1) -C(ll)-C(12) 103 . 9 (5) C(8) - C(ll) -C(12) 122 . 5 (15) Zr (1) -C(ll) -C(16) 101. 5 (5) C(8) - C(ll) -C(16) 117. 5 (15) C(9) - C(21) -C(22) 121 3 (15) co) - C(21) -C(26) 117 6 (15) C(33) -C(32) -C(37) 116 5(11) C(31) -C(32) -C(37) 123 1 (11) C(35) -C(36) -C(40) 121 . 1 (9) C(31) -C(36) -C(40) 118 7(9) N.(2) - C(31) -C(32) 118 . 0 (11) N(2) - C(31) -C(36) 122 0 (11) C(43) -C(42) -C(47) 120 6(9) C(41) -C(42) -C(47) 119 4 (9) C (45) -C (46) -C (50) 117 1 (10) C (41) -C (46) -C (50) 122 .3 (10) N(3) -C (41) -C (42) 122 5 (12) N(3) -C(41) -C(46) 117 .5 (12) C(32) -C(37)-C(38) 109 5 (17) C (32) -C(37) -C(39) 109 .5 (15) C (38) -C (37) -C (39) 109 .4(22) C(36) -C(40) -C(27) 109 .7(22) C(36) -C (40) -C (28) 109 6 (18) C(27) -C(40) -C(28) 109 .4 (20) C (42) -C(47) -C(48) 109 6 (17)_ C(42) -C(47) -C(49) 109 .5(20) C(48) -C(47) -C (49) 109 .5 (20)' C(46) -C(50) -C(51) 109 .6(16) C(46) -C(50)-C(52) 109 .6 (15) C(51) -C(50)-C(52) 109 .5 (22) Table S4 . /anisotropic displacement parameters (A2 x 10 ) . The anisotropic displacement factor exponent takes the form: -27T2 [h2a*2Ull + ... + 2hka*b*U12] atom Ull U22 U33 U23' U13 U12 Zr(l) 38(1) 33(2) 62(3) 9(2) 2(1) 0(4) 316 Table 1. Crystal data and structure refinement for 1. 317 Identification code Empirical formula Formula weight Temperature Wavelength Crystal system Space group Unit cell dimensions Volume, Z Density (calculated) Absorption coefficient F (000) Crystal size Theta range for data collection Limiting indices Reflections collected Independent reflections Refinement method Data / restraints / parameters Goodness-of-fit on F"2 Final R indices [I>2sigma(I)] R indices (all data) Absolute structure parameter Largest diff. peak and hole dmOOl C35.7 H48.5 N3 00.35 Zr 616 .49 298 (2) K 0.71073 A Tetragonal I-42d a = 16.155(3) A alpha = 90 deg b = 16.155(3) A beta = 90 deg c = 26.847(6) A gamma = 90 deg 7007(2) A~3, 8 1.169 Mg/rrT3 0.336 mm"-1 2612 0.20 x 0.10 x 0.10 mm 1.47 to 21.49 deg. -20<=h<=21, -21<=k<=15, -32<=1<= 11860 2019 [R(int) = 0.2999] Full-matrix least-squares on F~2 1998 / 6 / 186 1.029 RI = 0.0765, wR2 = 0.1635 RI = 0.1084, wR2 = 0.1929 0.0(2) 0.551 and -0.489 e.A"-3 318 Table 2. Atomic coordinates ( x 10*4) and equivalent isotropic displacement parameters (A~2 x 10*3) for 1. U(eq) is defined as one third of the trace of the orthogonalized Uij tensor. z U(eq) Zr 6917(1) 2500 1250 42 (1) N(l) 5489(8) 2500 1250 43 (3) N(2) 6469 (4) 3719(5) 1336 (3) 31(2) C(l) 7142 (7) 4753 (7) 1890 (4) 46(3) C(2) 7629(9) 5469 (8) 1952 (5) 62 (4) C(3) 7901(8) 5924 (8) 1544 (5) 62 (4) C(4) 7740(6) 5652(7) 1067 (5) 49 (4) C(5) 7261(6) 4926(7) 987 (4) 43(3) C(6) 6985(7) 4482 (7) 1411(4) 36(3) C(7) 6805 (9) 4334 (8) 2366 (4) 60(4) C(8) 6156(9) 4882 (9) 2606(5) 84 (5) C(9) 7504 (11) 4100 (9) 2714 (5) 92 (5) C(10) 7052 (8) 4716 (7) 451 (4) 48 (3) C(ll) 6424(10) 5346 (8) 243 (5) 86 (5) C(12) 7793 (9) 4663(9) 118(5) 98 (6) C(13) 5615 (7) 3963(6) 1342 (4) 42 (3) C(14) 5080 (7) 3223 (6) 1287 (4) 34 (3) C(15) 4201 (6) 3239(6) 1293 (4) 41 (3) C{16) 3805 (10) 2500 1250 53 (4) C(17) 7917 (15) 2166 (21) 1856 (9) 71 (10) CU8) 8272 (13) 2945 (15) 1585 (9) 42 (7) C(19) 8306 (13) 3069 (17) 1084(9) 66 (8) C(20) 8045 (15) 2386 (21) 712(10) 64 (8) C(91) 10097(35) 5301 (31) 1751(18) 105(18) C(92) 10000 5000 2056(34) 75(19) 0(90) 9816(46) 4801 (46) 2359 (20) 82(25) 319 Table 3. Bond lengths [A] and angles [deg] for 1. Zr-N(2)#l 2.111(8) Zr-N(2) 2.111(8) Zr-N(l) 2.307(13) Zr-C(20)#l 2.33(2) Zr-C(20) 2.33(2) Zr-C(17) 2.36(2) Zr-C(17)#l 2.36(2) Zr-C(19) 2.47(2) Zr-C(19)#l 2.47(2) Zr-C(18) 2.47(2) Zr-C(18)#l 2.47(2) N(l) -C(14) 1.346(11) N(l)-C(14)#l 1.346 (11) N(2) -C(13) 1.436 (12) N(2) -C{6) 1.501(13) C(l)-C(6) 1.382 (14) C(l)-C(2) 1.41(2) C(l)-C(7) 1.54 (2) C(2) -C(3) 1.39 (2) C(3) -C(4) 1.38 (2) C(4)-C(5) 1.42(2) C(5) -C(6) 1.418(13) C(5)-C(10) 1.52(2) C(7)-C(6) 1.52 (2) C(7)-C(9) 1.51(2) C(10)-C(12) 1.50(2) C(10)-C(ll) 1.54(2) C(13)-C(14) 1.483(13) C(14)-C115) 1.420(13) C(15)-C(16) 1.358 (12) C(16)-C(15)#l 1.358 (12) C(17)-C(1B) 1.56 (3) C(18)-C(19) 1.36(3) C(19) -C(20) 1.55(3) C(91)-C(92) 0.97(6) C(91) -C(91)#2 1.02(10) C(91) -O(90)#2 1.65(6) C(91)-O(90) 1.88(7) C(92)-O(90)#2 0.92(7) C(92)-O(90) 0.92(7) C(92)-C(91)#2 0.97(6) C{92)-O(90)#3 1.63(12) C(92) -O(90)#4 1.63(12) O(90)-O(90)#2 0.88(12) O(90)-O(90)#3 0.98(8) O(90)-O(90)#4 0.98(8) O(90)-C(91)#2 1.65(6) O(90)-C(92)#3 1.63(12) N(2)#l-Zr-N(2) 140.0(4) N(2)#l-Zr-N(l) 70.0 (2) N(2) -Zr-N(l) 70.0(2) N(2)#l-Zr-C(20)#l 114.2 (9) N(2)-Zr-C(20)#l 97.2 (8) N(l)-Zr-C(20)#l 141.4 (7) N(2)#l-Zr-C(20) 97.2(8) 320 N(2)-Zr-C(20) 114 .2 (9) N(l)-Zr-C(20) 141 .4 (7) C(20)#l-Zr-C(20) 77 .2 [14) N(2)#l-Zr-C(17) 95 .5 (8) N(2)-Zr-C(17) 111 .9 (9) N(l)-Zr-C(17) 133 .3 (6) C(20)#l-Zr-C(17) 19 .0 (9) C(20)-Zr-C(17) 82 .7 (9) N(2)#l-Zr-C<17)#l 111 .9 (9) N(2)-Zr-C(17)#l 95 .5 (8) N(l)-Zr-C(17)#l 133 .3 (6) C(20)#l-Zr-C(17)#l 82 .7 (9) C(20)-Zr-C(17)#l 19 .0 (9) C(17)-Zr-C(17)#l 93 .3 (13) N(2)#l-Zr-C(19) 129 .8 (6) N(2)-Zr-C(19) 89 .1 (6) N(l)-Zr-C(19) 155 .5 (6) C(20)#l-Zr-C(19) 51 .0 (9) C(20)-Zr-C(19) 37 .5 (7) C(17)-Zr-C(19) 65 .5 (9) C(n)*l-Zr-C(19) 33 .4 (8) N(2)#l-Zr-C(19)#l 89 .1 (6) N(2)-Zr-C(19)#l 129 .8 (6) N(l)-Zr-C(19)#l 155 .5 (6) C(20)#l-Zr-C(19)#l 37 .5 (7) C(20)-Zr-C(19)#l 51 .0 (9) C(17)-Zr-C(19)*l 33 .4 (8) C(17)#l-Zr-C(19)#l 65 .5 (9) C(19)-Zr-C(19)#l 49 .0 (12) N(2)#l-Zr-C(18) 127 .9 (6) N(2)-Zr-C(18) 89 .5 (6) N(l)-Zr-C(18) 152 .3 (5) C(20)#l-Zr-C(18) 20 .0 (8) C(20) -Zr-C(18) 63 .7 (8) C(17)-Zr-C(l8) 37 .7 (7) C(17)#l-Zr-C(18) 65 .0 (9) C(19)-Zr-C(18) 32 .0 (7) C(19)#l-Zr-C(1B) 40 .3 (7) N(2)#l-Zr-C(18)#l 89 .5 (6) N(2)-Zr-C(18)#l 127 .9 (6) N(l) -Zr-C(18)#l 152 .3 (5) C(20)#l-Zr-C(18)#l 63 .7 (8) C(20)-Zr-C(18)#l 20 .0 (8) C(17)-Zr-C(18)#l 65 .0 (9) C(17)#l-Zr-C(18)#l 37 .7 (7) C(19)-Zr-C(18)#l 40 .3 (7) C(19)#l-Zr-C(18)#l 32 .0 (7) C(18)-Zr-C(18)#l 55 .5 (11) C(14)-N(l)-C(14)#l 121 .2 (13) C(14)-N(l)-Zr 119 .4 (6) CU4)#1-N(1)-Zr 119 .4 (6) C(13)-N(2)-C<6) 107 .9 (8) C(13)-N(2)-Zr 125 .9 (6) C(6)-N(2)-Zr 126 .2 (6) C(6)-C(l)-C(2) 118 .1 (11) C(6)-C(l)-C(7) 124 .4 (11) C(2)-C(l)-C{7) 117 .4 (10) C(3)-C(2)-C(l) 121 .2 (11) C(4)-C(3)-C(2) 120 .3 (12) C(3)-C(4)-C(5) 120 .2 (11) C(6)-C(5)-C{4) C(6)-C(5)-C(10) C(4) -C(5) -C(10) C(l)-C(6)-C(5) C(l) -C(6) -N(2) C(5) -C(6) -N(2) C(8)-C(7)-C<9) C(8) -C(7)-C(l) C(9)-C(7)-C[l) C(12) -C(10)-C(5) C(12)-C(IO)-C(ll) C(5)-C(10)-C(ll) N(2)-C(13)-C(14) N(l)-C(14)-C(15) N(l)-C(14)-C(13) C(15)-C{14)-C(13) C(16)-C(15)-C(14) C(15)-C(16)-C(15)#l C(18)-C(17)-2r C(19)-CUB)-C(17) C(19)-C(18)-Zr C(17)-CU8)-Zr C(18) -C(19) -C(20) C(18)-C(19)-Zr C(20)-C(19)-Zr C(19) -C(20)-Zr C(92)-C(91)-C(91)#2 C(92)-C(91)-O(90)#2 C(91)#2-C<91)-O(90)#2 C(92)-C(9l)-0(90) C(91)#2-C(91)-0(90) O(90)#2-C(91)-O(90) O(90)#2-C(92)-O(90) O(90)*2-C(92)-C(91) 0(90)-C(92)-C(91) O(90)#2-C(92)-C(91)#2 O(90)-C(92)-C{91)#2 C(91)-C(92)-C(91)#2 O(90)#2-C(92)-O(90)*3 O(90)-C(92) -O(90)#3 C(91)-C(92)-O(90)#3 C(91)#2-C(92) -O(90)*3 O(90)#2-C(92)-O(90)#4 O(90)-C(92)-O(90)#4 C(91)-C(92)-O(90)#4 C(91)#2-C(92)-O(90)#4 O(90)#3-C(92)-O(90)*4 O(90)*2-O(90)-C(92) O(90)#2-O(90)-O(90)#3 C(92)-O(90)-O(90)#3 O(90)#2-O(90)-O(90)#4 C(92)-O(90)-O(90)#4 O(90)#3-O(90)-O(90)#4 O(90)#2-O(90)-C(91)#2 C(92)-O(90)-C(91)#2 O(90)#3-O(90)-C(91)#2 O(90)#4-O(90)-C(91)#2 O(90)#2-O(90)-C(92)#3 C(92)-0(90)-G(92)#3 O(90)#3-O(90)-C(92)#3 118.0(10) 125.4(10) 116.6(10) 121.9(10) 119.2 (10) 118.8(8) 113.5(13) 109.9 (11) 110.9(12) 113.7(11) 110.4(11) 110.0(10) 109.8(8) 120.4(10) 114.9(9) 124.6(9) 117.0(11) 124(2) 75.3(12) 126(2) 73.7 (14) 67.0(11) 121(2) 74 (2) 66.6(11) 76.0(11) 58 (4) 29(3) 86(3) 6(3) 61(2) 28(4) 57 (9) 121(4) 167 (7) 167 (7) 121(4) 64(8) 32(5) 32(5) 139(4) 151(5) 32(5) 32(5) 151(5) 139(4) 31(6) 62(4) 63(4) 116(9) 63(4) 118(9) 53(8) 91(3) 30(3) 146(8) 136(8) 74(3) 136(7) 30(5) O(90)#4 -0(90) -C(92)#3 30(5) C(91)#2 -0(90) -C(92)#3 163(6) O(90)#2 -0(90) -C(91) 61(3) C(92)-0(90)-C(91) 7(3) O(90)#3 -0(90) -C(91) 114(7) O(90)#4 -0(90) -C(91) 121(7) C(91)#2 -0(90) -C(91) 33 (3) C(92)#3 -0(90) -C(91) 135(4) Symmetry transformations used to generate equivalent atoms: #1 x+i-i,-y+l/2,-z+i/4 #2 -x+2,-y+l,z #3 y+l/2,-x+3/2,-z+1/2 #4 -y+3/2,x-l/2,-z+l/2 323 Table 4. Anisotropic displacement parameters (A*2 x 10*3) for l. The anisotropic displacement factor exponent takes the form: -2 pi*2 t h*2 a**2 Ull • ... + 2 h k a* b* U12 ] Ull U22 U33 U23 U13 U12 Zr N(l) N(2) C(l) C(2) C(3) C(4) C(5) C(6) C(7) C(8) CO) C(10) C(ll) CU2) C(13) C(14) C(15) C(16) 36(1) 80(10) 17(4) 48(9) 64(10) 46(9) 41(9) 33(8) 44 (7) 77 (10) 85(11) 94(11) 71(9) 114 (13) 129 (18) 70 (9) 67 (8) 35 (7) 44 (10) 40(1) 46(9) 55(6) 47(9) 58(9) 53(9) 37(8) 46(8) 33(7) 60(9) 92(12) 126(14) 39(8) 67(10) 115(14) 31(7) 19 (6) 39 (7) 69 (13) 51(1) 13(6) 22(6) 43(8) 64(9) 64(11) 68(9) 50(B) 31(7) 42 (7) 74(10) 57(9) 33 (7) 77 (10) 50(8) 25 (7) 18(6) 47 (7) 46(10) -2(1) 16(8) 8(5) -16(6) -20(8) -8(8) -7(6) 1(6) -9(5) 6(7) 1(9) 15(8) -6(6) 22 (8) -1 (9) 6(6) -4 (6) 0(7) -24(12) 0 0 8(4) •17(6) -14(8) -5(8) -1(6) -5(6) 2(6) -9(6) 14(9) -15(10) 14(7) -20 (10) 29 (10) -3(6) -6(7) -1 (7) 0 0 0 9(4) 3(7) •17(9) -15(7) 4(6) 6(6) 3(6) -2(8) 19(10) -2(14) -9(7) -12(10) 2(11) -5(6) 3(5) 6(5) 0 325 Table 1. Crystallographic data for 1. formula C2]H35N3Zr formula weight 420.74 crystal system monoclinic space group P2,/n • a, A 10.4355(5) b, A 10.0209(5) c. A 21.190(1) b. 0 95.226(1) V, A 2206.6(2) Z 4 p. g cm' 1.266 T IT 0.2786/0.2345 R[F), % 4.46 R(wF*). % 7.88 Quantity minimized = RiwF*) = IMF/ - Fra)sJ; R = IA/KFJ. A = | (F0 - Fr) I Table 1. Crystal data and structure refinement for 1. 326 Identification code Empirical formula Formula weight Temperature Wavelength Crystal system Space group Unit cell dimensions Volume, Z Density (calculated) Absorption coefficient F(000) Crystal size Theta range for data collection Limiting indices Reflections collected Independent reflections Absorption correction Max. and min. transmission Refinement method Data / restraints / parameters Goodness-of-fit on F*2 Final R indices [I>2sigma(I)] R indices (all data) Extinction coefficient Largest diff. peak and hole dm004 C21 H35 N3 Zr 420.74 298(2) K 0.71073 A Monoclinic P2(l)/n a «= 10.4355(5) A b «= 10.0209(5) A c « 21.190(1) A alpha « 90 deg. beta - 95.226(1) deg gamma * 90 deg. 2206.6(2) A*3, 4 1.266 Mg/irT3 0.506 mm*-l 888 0.15 x 0.15 x 0.10 mm 1.93 to 25.00 deg. -13«=h<Bl3, -12c=k<«13, -17<«le«:28 10235 3840 IR(int) « 0.0539) Semi-empirical from psi-scans 0.2786 and 0.2345 Full-matrix least-squares on F"2 3B39 / 0 / 227 1.014 RI * 0.0446, wR2 - 0.0788 RI * 0.0644, wR2 - 0.0902 0.0109(6) 0.439 and -0.342 e.A*-3 Table 2. Atomic coordinates ( x 10*4) and equivalent isotypic displacement parameters (A*2 x 10*3) for l. U(eq) is defined as one third of the trace of the orthogonalized Uij tensor. U(eq) Zr N(l) N{2) N(3) C(l) C(2) C(3) C(4) C(5) C(6) C(7) C(B) C(9) C(10) C(ll) C(12) C(13) C(14) C(15) C(16) C(17) C(18) C(19) C(20) C(21) 7530(1) 7994 (3) 9622(3) 8354 (3) 6433 (4) 5289 (4) 5635(5) 6189(5) 7329 (4) 6968(3) 9191(3) 10106(3) 11337(4) 12073(4) 11582(4) 10341(3) 9669 (4) 7911(4) 6928(5) 6665(5) 6234 (4) 7218 (4) 7498 (4) 5620(4) 6982 (4) 2201 (1) 3400(3) 3019(3) 1598(3) 4987 (4) 5060(5) 4541(5) 3154 (5) 3085(4) 3570(4) 4095(4) 3828(4) 4348 (4) 4020(4) 3198(4) 2710(4) 1842(4) -491(4) -1177(4) -336(5) 1050(5) 1729 (4) 908(4) 3071 (4) 238 (4) 324(1) 1111(1) 328(1) -483(1) 1556(2) 1955(2) 2621(2) 2619(2) 2216(2) 1543(2) 1295(2) 801(2) 809 (2) 319(2) -165(2) -152 (2) -644(2) -1127(2) -1605(2) -2203(2) -2043(2) -1567(2) -964(2) -84 (2) 764(2) 40(1) 45(1) 42(1) 45(1) 57(1) 78(2) 78(2) 79(2) 64(1) 46(1) 55(1) 46(1) 57 (1) 62 (1) 54 (1) 46 (1) 61(1) 61(1) 78 (1) 82 (2) 79(1) 59(1) 47(1) 62(1) 67(1) Table 3. Bond lengths [A] and angles [deg] Zr-N(3) Zr-N(i) Zr-C(21) Zr-C(20) Zr-N(2) N(l) -C(7) N(l) -C(6) N(2)-C{8) N(2)-C(12) K(3)-C<13) N(3)-C(19) C(l) -C(2) C(l)-C(6) C(2)-C(3) C(3)-C(4) C(4)-C(5) C(5)-C{6) C(7) -C<8) C(8)-C(9) C(9)-C(10) C(10)-C(ll) Clll) -C(12) C(12)-C(13) C(14) -C(19) CU4) -C(1S) C(15)-C(16) C(16)-C(17) C(17)-C(18) C(18)-C(19) N(3) -Zr-N(l) N{3)-2r-C(21) N(l) -2r-C(21) N(3) -Zr-C(20) N(l) -Zr-C(20) C (21)-Zr-C(20) N(3)-Zr-N(2) K(l) -Zr-N(2) C(21) -Zr-N(2) C(20)-Zr-N(2) C{7) -N(l) -C(6) C(7) -N(l) -Zr C(€)-N(l)-Zr C(8)-K(2)-C(12) C(8) -N(2)-Zr C(12)-N(2)-Zr C(13)-N(3)-C(19) C(13)-N(3)-Zr C(19)-N(3)-Zr C(2)-C(l)-C(6) C(3)-C(2)-C(l) C(4)-C(3)-C(2) C(3)-C(4)-C(5) C(6) -C(5) -C(4) N(l)-C(6)-C(5) N(l)-C(6)-C(l) 1. 1. 1, 1 2.073(3) 2.076(3) 2.272 (4) 2.272 (4) 2.332(3) 1.453(4) 1.481(4) 1.351(4) 1.352(4) 1.464(4) .466(4) .526(5) .526(5) .517(6) 1.504 (6) 1.528(5) 1.521(5) 1.503(5) 1.384 (5) 1.387 (5) ,377(6) .387 (5) .484 (5) .516(5) 1.538 (6) 1.525 (6) 1.508(6) 1.533(5) 1.524(5) 1. 1. 1, 1, 138. 103. 102. 102. 102 . 104 . 69. 69. 124 . 130. 115. 128. 115. 120. 120. 120, 116, 127 116 111 111 112 111 111 114 113 36 (11) 00(14) 74 (14) 31 (14) 46(13) 1(2) 30(11) 16(11) ,99(13) ,92(13) .6(3) .7(2) .8(2) .0(3) .0(2) .0(2) .2(3) .7(2) .0(2) .1(3) .5(4) .0(4) .2(4) .7(4) .3(3) 8(3) C(5)-C(6)-C(l) 109 9(3) N(l) -C(7) -0(8) 108 3(3) N(2)-C(8)-C(9) 121 3(4) N(2)-C(8)-C(7) 113 .9(3) C(9)-C(8)-C(7) 124 .8(4) C(8) -C(9) -C(10) 118 .6(4) C(ll)-C(10)-C(9) 120 .3(4) C(10)-C(ll)-C(12) 118 .7(4) N(2)-C(12)-C(ll) 121 .2(4) N(2) -G(12) -C(13) 113 .7(3) C(ll)-C(12)-C(13) 125 .1(4) N(3)-C(13)-C(12) 109 .1(3) C(19)-C(14)-C(15) 112 .1(3) C(16)-C(15)-C(14) 111 .0(4) C(17)-C(16)-C(15) 111 .0(4) C(16)-C(17)-C(18) 111 .2(4) C(19)-C(18)-C(17) 112 .2(3) N(3)-C(19)-C(14) 115 .2(3) N(3) -C{19) -C{18) 112 .7(3) C(14) -C(19) -C(18) 110 .3 (3) 329 Symmetry transformations used to generate equivalent atoms: 330 Table 4. Anisotropic displacement parameters (A*2 x 10*3) The anisotropic displacement factor exponent takes the form: -2 pi*2 [ h*2 a**2 Ull • ... + 2 h k a* b* U12 ] Ull U22 U33 U23 U13 U12 Zr N{1) N(2) NO) C(l) C(2) C(3) C(4) CO) C(6) C(7) C(8) CO) C(10) C(ll) C(12) C(13) C(14) C(15) C(16) C(17) C(18) C(19) C(20) C(21) 30(1) 34(2) 30(2) 35(2) 61(3) 68(3) 72(3) 101(4) 78 (3) 41(2) 46(2) 36(2) 36 (2) 35 (2) 38 (2) 35 (2) 46 (2) 75(3) 103 (4) 95 (4) 86 (4) 64 (3) 45 (2) 46 (2) 69 (3) 4B(1) 58(2) 50(2) 61(2) 59(3) 88(4) 98(4) 78(4) 67(3) 52 (2) 70(3) 49(2) 57(3) 61 (3) 58(3) 54 (2) 81 (3) 55(3) 56 (3) 91 (4) 81 (4) 55 (3) 55(3) 65(3) 61(3) 40(1) 44(2) 45(2) 38(2) 51(3) 79(4) 70(4) 61(3) 49(3) 44 (2) 47(3) 52(3) 74(3) 91 (4) 68(3) 47 (2) 56(3) 52 (3) 73(4) 59(3) 64 (3) 53 (3) 42 (2) 74(3) 74 (3) -2(1) -5(2) 3(2) -6(2) 4(2) -12(3) -12(3) 4(3) 14(2) -6(2) -7(2) 2(2) -3 (2) 13(3) 11(2) 8(2) -5(2) 3(2) -10(3) -12(3) 2 (3) 3(2) 0(2) -8(2) 0(3) 3(1) 2(2) 2(2) 5(2) 6(2) 22(3) 32(3) 29(3) 17(2) 5(2) -2(2) -4(2) -8(2) 9(3) 15(2) 1(2) 10(2) 6(2) 5(3) -6(3) -26(3) -16(2) 5(2) 0(2) 15(3) 2(1) 1(2) 3 (1) 2(2) 11(2) 24 (3) -4(3) -8(3) 16(2) 1(2) -3(2) 2 (2) -4 (2) -1 (2) 6(2) 9 (2) 9 (2) 0(2) -11(3) -25.(3) -5(3) 4(2) 2(2) 10(2) -2(2) 331 Table 5. Hydrogen coordinates (^x 10*4) and isotropic displacement parameters (A*2 x 10*3) for 1. x y z U(eq) H(1A) 7103 (4) 5588 (4) 1731 (2) 68 H(1B) 6167(4) 5273 (4) 1127 (2) 68 H(2A) 5003 (4) 5979 (5) 1976 (2) 93 H(2B) 4583 (4) 4538 (5) 1753(2) 93 H(3A) 6257(5) 5136 (5) 2841 (2) 94 H(3B) 4871 (5) 4535 (5) 2849 (2) 94 H(4A) 5528 (5) 2534 (5) 2453 (2) 95 H(4B) 6467 (5) 2891(5) 3051 (2) 95 H(5A) 8026 (4) 3629 (4) 2410 (2) 77 H(5B) 7632 (4) 2171 (4) 2204 (2) 77 H(6) 6204 (3) 3034 (4) 1343 (2) 55 H(7A) 9557 (3) 3779(4) 1705 (2) 66 H (7B) 9035(3) 5046 (4) 1325 (2) 66 H (9A) 11662 (4) 4904(4) 1137 (2) 68 H(10A) 12904 (4) 4356 (4) 317 (2) 74 H(11A) 12073 (4) 2974 (4) -494 (2) 65 H(13A) 9650(4) 2271 (4) -1054 (2) 73 H(13B) 10124 (4) 1001 (4) -665 (2) 73 H(14A) 8018 (4) -1021 (4) -742 (2) 73 HC14B) 8737 (4) -450(4) -1302(2) 73 H(15A) 7255 (5) -2044(4) -1717 (2) 93 H(15B) 6130 (5) -1316(4) -1413 (2) 93 H(16A) 7441(5) -280 (5) -2421 (2) 99 H(16B) 6003 (5) -761 (5) -2485 (2) 99 H(17A) 5411 (4) 1000(5) -1866 (2) 95 H(17B) 6122 (4) 1580 (5) -2427 (2) 95 H(18A) 8012 (4) 1866 (4) -1762(2) 71 H(18B) 6893 (4) 2598 (4) -1457 (2) 71 H(19) 6686 (4) 818(4) -786 (2) 57 H(20A) 5149 (4) 3387 (4) 254 (2) 93 H(20B) 5130 (4) 2394 (4) -318 (2) 93 H(20C) 5776 (4) 3799 (4) -362 (2) 93 H(21A) 6586 (4) 412 (4) 1147 (2) 101 H(21B) 7740 (4) -294(4) 859 (2) 101 H(21C) 6388 (4) -234 (4) 472 (2) 101 332 9 Crystallographic data for (tBAP)ZrMe2. 333 Table 1. Crystal data and structure refinement for 1. 334 Identification code Empirical formula Formula weight Temperature Wavelength Crystal system Space group Unit cell dimensions Volume, Z Density (calculated) Absorption coefficient F(000) Crystal size Theta range for data collection Limiting indices Reflections collected Independent reflections Absorption correction Max. and min. transmission Refinement method Data / restraints / parameters Goodness-of-fit on F*2 Final R indices [I>2sigma(I)] R indices (all data) Largest diff. peak and hole dm005 C17 H31 N3 Zr 368.67 296 (2) K 0.71073 A Monoclinic C2/C a - 31.9923(9) A b * 9.9689(3) A c « 17.9912(5) A alpha • 90 deg. beta - 93.196(1) deg. gamma = 90 deg. 5729.0(3) A*3, 12 1.282 Mg/m~3 0.575 mrrT-1 2328 0.30 x 0.20 x 0.20 mm 1.27 to 28.29 deg. -42c=h<=42, -5<=k<=13, -23<=1<=22 17656 6836 (R(int) = 0.0161] Semi-empirical from psi-scans 0.862128 and 0.701441 Full-matrix least-sguares on F"2 6836 / 0 / 286 1.059 RI - 0.0339, wR2 « 0.0983 RI « 0.0416, wR2 « 0.1040 0.450 and -0.375 e.A"-3 335 Table 2. Atomic coordinates ( x 10*4) and equivalent isotropic displacement parameters (A*2 x 10*3) for 1. U(eq) is defined as one third of the trace of the orthogonalized Uij tensor. U(eq) Zr(l) N(l) N(2) N{3) C(l) C(2) C(3) C(4) C(5) C(6) C(7) C(8) C(9) C(10) C(ll) C(12) C(13) C(14) C(15) C(16) C(17) Zr(2) N(l' N(2' C (1' C(2' C{3' C(4' C(5' C(6* C(7' C(8' C(9' 3352(1) 3379 (1) 2736(1) 2953 (1) 4079(1) 3961(1) 3651(1) 3757(1) 3043(1) 2681(1) 2312 (1) 1999 (1) 2056 (1) 2430 (1) 2531(1) 3070(1) 2776 (2) 3059(2) 3518 (1) 3435 (1) 3893(1) 5000 5000 4695 (1) 5000 4820(1) 4823(1) 4644 (1) 4510 (1) 4033 (1) 4717 (1) 4576 11) 5526(1) 9125(1) 10560(2) 9092(2) 7648 (2) 11200(3) 10935(5) 12888(3) 11391(3) 10809(3) 9919(2) 9917(3) 9032 (3) 8174(3) 8233(2) 7378(3) 6779(3) 7054(6) 5297 (4) 7093 (4) 10472 (3) 7798 (3) 6714 (1) 9018 (3) 7419 (2) 11776 (5) 11093 (3) 9695 (3) 8826 (3) 6525 (4) 6768 (5) 6747 (5) 5051(4) 5493 (3) 6577(1) 5712 (1) 5866 (1) 6994 (1) 6236 (2) 4875(2) 5528(3) 5586(2) 5154(2) 5278(1) 4835(1) 4995(2) 5599(2) 6029 (1) 6691(1) 7649(2) 8285 (2) 7432(3) 7934 (2) 7605 (2) 6263 (2) 2500 2500 3432 (1) 2500 3055 (2) 3047 (2) 3616 (2) 3994 (2) 4000(3) 4769 (2) 3775 (2) 3081(2) 42(1) 48(1) 43(1) 51(1) 77 (1) 96(1) 92(1) 59(1) 58(1) 48(1) 57(1) 64 (1) 60 (1) 49 (1) 55 (1) 67 (1) 111 (2) 114 (2) 88 (1) 71(1) 64 (1) 46(1) 50(1) 58 (1) 92 (2) 83 (1) 58 (1) 72 (1) 74 (1) 108 (2) 103 (1) 96 (1) 70(1) 336 Table 3. Bond lengths [A] and angles [deg] for 1. Zr (1) -N(3) Zr(1)-N(l) Zr(1)-C(17) Zr(1)-N(2) Zr(l)-C(16) N(l) -C(5) N(l) -C(4) N(2) -C(10) N(2) -C(6) N(3) -C(ll) N(3) -C(12) C<1)-C(4) C(2) -C(4) C(3) -C(4) C(5) -C(6) C(6)-C(7J C(7)-C(8) C(8)-C(9) C(9)-C(10) C(10)-C(ll) C(12)-C(14) C{12)-C(15) C(12) -CU3) Zr(2)-N (2 1 ) Zr(2) -N{2* )#l Zr(21-C(9') Zr(2)-CO1)#1 2r(2) -N(l' ) Nd1 ) -C(3' )#1 Nd1 ) -C(3' ) N(2')-C(4') N(2') -C(5 1 ) Cll')-C(2') C(l')-C(2')*l C(2' ) -C(3' ) C(3')-C(4') C(5' ) -C(7' ) C(5')-C(81) C(5')-C(61) N(3) -Zr (1) -N(l) N(3)-Zr(l)-C(17) Nd)-Zr(l) -C(17) N(3) -ZrU) -N(2) N(l)-Zr(l)-N(2) C(17)-Zr(l)-N(2) N(3)-Zr(l)-C(16) N(l)-Zr(l)-C(16) C(17)-Zr(l)-C(16) N(2)-Zr(l)-C(16) C(5) -N(l) -C(4) C(5)-N(l)-Zr(l) C(4)-N(l)-Zr(l) CdO) -N(2) -C(6) C(10) -N(2) -Zr(l) C(6)-N(2)-Zr(l) 2.115(2) 2.118(2) 2.274 (3) 2.290(2) 2.290(3) 1.451(3) 1.494(3) 1.344(3) 1.345(3) 1.451(3) 1.494 (3) 1.526(4) 1.537(5) 1.532(4) 1.484 (4) 1.390(3) 1.376 (4) 1.386 (4) 1.389 (3) 1.485 (4) 1.528 (5) 1.525(5) 1.545(5) 2.106(2) 2.106(2) 2 .281 (3) 2.281(3) 2.297(3) 1.344(3) 1.344(3) 1.452 (4) 1.495(4) 1.362(5) 1.362 (5) 1.394(4) 1.480(4) 1.527(5) 1.539(6) 1.545(5) 141.29(8) 99.56(10) 98.56(10) 70.66(7) 70.64(7) 119.79(9) 99.54(11) 100.98(11) 119.13(12) 121.08(10) 112.0(2) 124.4 (2) 123.5(2) 119.9(2) 120.2(2) 119.9(2) 337 C(ll) -N(3)-CU2) 112.1(2) C(ll)-N(3)-Zr (1) 124.3(2C(12)-N(3)-Zr(l) 123.6(2) N(l)-C(4)-C(l) 109.4(2N(l)-C(4) -C(3) 111.9(2) C(l)-C(4)-C(3) 108.1(3N(l)-C(4)-C(2) 110.4(2) C(l)-C(4)-C(2) 107.4(3C(3)-C(4)-C(2) 109.5(3) N{1)-C(5)-C(6) 110.3(2N(2)-C(6)-C(7) 121.3(2) N(2)-C(6)-C(5) 114.7(2C(7)-C(6)-C(5) 124.0(2) C(8)-C(7)-C(6) 119.0(3C(7)-C(8)-C(9) 119.7(2) C(10)-C(9)-C(8) 118.7(3N(2)-C(10)-C(9) 121.4(2) N{2) -C(10)-C(ll) 114.3(2C(9)-C(10) -C(ll) 124.4(2) N(3)-C(ll)-C(10) 110.6(2N(3)-C(12)-C(14) 111.0(3) N(3)-C(12)-C(15) 109.6(2C(14)-C(12)-C(15) 107.0(3) N(3)-CU2)-CU3) 110.2(3C(14)-C(12)-C(13) 110.8(3) C(15)-C(12)-C(13) 108.2(3N(2•)-Zr(2)-N(2')#1 141.01(13) N(2')-Zr(2)-C(9') 100.11(11N(2')#1-Zr(2)-C(9') 100.40(11) N(2')-Zr(2)-C(9')#l 100.40(11N(2')#l-Zr(2)-C(9')*l 100.11(11) C<9')-Zr (2)-CO')#1 115.5(2) N(2')-Zr(2)-N(l«) 70.50(6N(2')#l-Zr(2)-N(l') 70.50(6) C(9')-Zr (2)-N(l') 122.24(8C(9')-#l-Zr(2)-N(l') 122.24 (8) C(3')*1-N(1')-C(3') 119.7(3C(3')#l-N{l')-Zr(2) 120.1(2) C(3')-N(l')-Zr(2) 120.1(2C(4')-N(2,)-C(5') 111.6(2) C(4')-N(2')-Zr(2) 124.5(2C(5')-N(2')-Zr(2) 123.9(2) C(2,)-C(l')-C(2')#l 120.0(4) C(l')-C(2')-C(3') 119.3(4N(l')-C(3')-C(2') 120.6(3) N(l')-C(3')-C(4') 114.0(2C(2')-C(3')-C(4') 125.1(3) N(2')-C(4')-C(3') 110.8(2N(2')-C(5')-C(7») 111.3(3) N(2')-C(5,)-C{8') 109.3(3C(7,)-C(5,)-C(8,) 108.2(3) N(2,)-C(5,)-C(6') 109.9(3C(7')-C(5')-C(6') 110.4(3) C(8')-C(5')-C(6') 107.6(3Symmetry transformations used to generate equivalent atoms: #1 -x+l,y,-z+l/2 338 Table 4. Anisotropic displacement parameters (A"2 x 10*3) for 1. The anisotropic displacement factor exponent takes the form: -2 pi~2 [ h*2 a*~2 Ull + ... + 2 h k a* b* U12 .] Ull U22 U33 U23 U13 U12 Zr(l) 41 (1) 45(1) 40(1) -1(1) -5(1) 3(1) N(l) 45 (1) •47(1) 52(1) 4(1) -5(1) 1(1) N(2) 42 (1) 46 (1) 41(1) -7(1) -2(1) 2(1) N(3) 57 (1) 53 (1) 43 (1) 3(1) 2(1) -1(1) C(l) 53 (2) 71 (2) 104 (2) 15 (2) -17 (2) -11 (1) C(2) 72 (2) 122 (4) 97 (3) 3(2) 26(2) -16(2) C(3) 80 (2) 54 (2) 138 (3) 16(2) -29 (2) -6(2) C(4) 52 (1) 51(1) 72 (2) 8(1) -3(1) -3(1) C(5) 58 (1) 59 (2) 57 (1) 12 (1) -9(1) 0(1) C(6) 49(1) 50(1) 44 (1) -9(1) -5(1) 8(1) C(7) 55(1) 63 (2) 51 (1) -9(1) -13(1) 13(1) C(8) 44 (1) 76(2) 70(2) -22(1) -15(1) 9(1) C(9) 41 (1) 65 (2) 73 (2) -16(1) 1(1) -1(1) C(10) 45 (1) 51 (1) 51 (1) -14(1) 3 (1) 2(1) C(ll) 54 (1) 55 (1) 56(1) -3 (1) 9(1) -5(1) C(12) 84 (2) 68 (2) 51 (1) 12 (1) 3(1) -4 (2) C(13) 117 (3) 162 (4) 55(2) 28 (2) 18 (2) -10(3) C(14) 171 (5) 59 (2) 106 (3) 22 (2) -37 (3) -1 (2) C(15) 97 (3) 96 (3) 68 (2) 28 (2) -22 (2) -2 (2) C{16) 74 (2) 75 (2) 62 (2) -21 (2) -11(1) 1 (2) C(17) 57 (2) 58 (2) 78 (2) 4 (1) 2(1) 13 (1) Zr (2) 38 (1) 38 (1) 61 (1) 0 -2(1) 0 N(l' ) 45 (1) 42 (1) 61 (2) 0 -5(1) 0 N(2' ) 53 (1) 57 (1) 63 (1) 11(1) 6 (1) 10 (1) C(l' ) 103(4) 38 (2) 131(5) 0 -8(3) 0 C(2 ' ) 84 (2) 55 (2) 107 (3) -16 (2) -7 (2) 15 (2) • C(3' ) 54 (1) 47 (1) 73 (2) -6(1) -7(1) 10 (1) C(4' ) 72 (2) 70 (2) 74 (2) -4 (2) 12 (2) 19 (2) C(5' ) 59 (2) 87 (2) 76 (2) 26 (2) 14 (1) 9 (2) C(6') 62 (2) 125(4) 140 (4) 47 (3) 27 (2) 9 (2) C{7') 103 (3) 134 (4) 75 (2) 32 (2) 12 (2) 16 (3) C(8' ) 99 (3) 79(2) 113 (3) 43 (2) 20(2) -1(2) C(9' ) 57(2) 53 (2) 99 (2) -3(2) -15(2) 7(1) 339 Table 5. Hydrogen coordinates (^x 10*4) and isotropic displacement parameters (A*2 x 10*3) for 1. U(eq) H(1A) 4149(1) 10267(3) 6282 (2) 115 H(1B) 3963 (1) 11506(3) 6687 (2) 115 H('1C) 4326 (1) 11708(3) 6146 (2) 115 H(2A) 3766(1) 11043(5) 4455(2) 145 H12B) 4040(1) 10008(5) 4922 (2) 145 HOC) 4206 (1) 11469 (5) 4805 (2) 145 H(3A) 3448 (1) 13031(3) 5122(3) 138 HOB) 3900 (1) 13387(3) 5442 (3) 138 HOC) 3538(1) 13184(3) 5984(3) 138 HOA) 3142 (1) 10647(3) 4662 (2) 70 HOB) 2955(1) 11739 (3) 5179(2) 70 H(7A) 2276(1) 10506(3) 4435(1) 68 HOA) 1751(1) 9010(3) 4700(2) 77 HOA) 1848 (1) 7570(3) 5714(2) 72 H(11A) 2333 (1) 7555(3) 7067(1) 66 H(11B) 2507 (1) 6441 (3) 6551(1) 66 H(13A) 2788(2) 7989 (6) 8413 (2) 166 HU3B) 2864 (2) 6528 (6) 8713 (2) 166 H(13C) 2495(2) 6817 (6) 8125(2) 166 H(14A) 2781(2) 5060 (4) 7251 (3) 170 HU4B) 3139(2) 4760 (4) 7859 (3) 170 H(14C) 3250 (2) 5141 (4) 7048 (3) 170 H (15A) 3538(1) 8021(4) 8073 (2) 132 H(15B) 3706(1) 6913 (4) 7549 (2) 132 H(15C) 3591 (1) 6542(4) 8359(2) 132 H(16A) 3614 (1) 11212(3) 7500(2) 107 H(16B) 3558 (1) 9963 (3) 8014 (2) 107 H(16C) 3167 (1) 10805(3) 7734 (2) 107 H(17A) 4106 (1) 8341 (3) 6059(2) 97 H(17B) 3794 (1) 7151(3) 5900(2) 97 H(17C) 4007(1) 7342 (3) 6698(2) 97 H(l'A) 5000 12709 (5) 2500 110 HO'A) 4697 (1) 11554 (3) 3436(2) 99 H(4'A) 4783 (1) 9008 (3) 4098(2) 86 H(4'B) 4349 (1) 9026(3) 3645(2) 86 HO'A) 3907(1) 6626(5) 3509(3) 162 H(6'B) 3982(1) 7673 (5) 4153(3) 162 H(6'C) 3914 (1) 6156(5) 4341(3) 162 HO'A) 4680(1) 7664 (5) 4914 (2) 155 H(7'B) 5010(1) 6548(5) 4762(2) 155 H(7'C) 4590(1) 6167(5) 5118(2) 155 HO'A) 4448(1) 4891(4) 3288(2) 145 HO'B) 4452 (1) 4474 (4) 4129(2) 145 HO'C) 4871(1) 4868 (4) 3771(2) 145 HO'A) 5695(1) 5100(3) 2715(2) 106 HO'B) 5407(1) 4796(3) 3372(2) 106 HO'C) 5695(1) 6069(3) 3401(2) 106 10 Crystallographic data for (tBAP)ZrMe(Me:CI, 60:40). Table l. Crystal data and strut Identification code Empirical formula Formula weight Temperature Wavelength Crystal system Space group Unit cell dimensions Volume, Z Density (calculated) Absorption coefficient F(000) Crystal size Theta range for data collection Limiting indices Reflections collected Independent reflections Absorption correction Max. and min. transmission Refinement method Data / restraints / parameters Goodness-of-fit on F*2 Final R indices [I>2sigma(I)] R indices (all data) Largest diff. peak and hole re refinement for l. ' J"Ti dm003 C16.64 H29.90 CIO.37 N3 Zr 376.12 298(2) K 0.71073 A Monoclinic P2(l)/c a « 10.4496(3) A alpha « 90 deg. b - 11.0371(3) A beta « 97.968(1) c = 16.6923(5) A gamma « 90 deg. 1906.59(9) A*3, 4 1.310 Mg/m~3 0.627 mrrT-1 788 0.20 x 0.10 x 0.10 mm 1.97 to 28.26 deg. -13<=hc=7, -14<=k<«14, -21<«lc=20 11760 4515 [R(int) * 0.0263] Semi-empirical from psi-scans 0.2919 and 0.2397 Full-matrix least-sguares on F*2 4510 / 0 / 200 1.167 RI « 0.0459, vR2 • 0.1180 RI - 0.0575, wR2 - 0.1288 0.612 and -0.333 e.A*-3 342 Table 2. Atomic coordinates ( x 10*4) and equivalent isotropic displacement parameters (A*2 x 10*3) for 1 U(eq) is defined as one third of the trace of the orthogonalized Ui3 tensor. U(eq) Zr 2205(1) 3783(1) Cl 3651(4) 3370(6) C 3312(10) 3284(13) N(l) 2133 (3) 5679(3) N(2) 3001(2) 4600(2) N(3) 2774 (3) 2380(2) C(l) 24(4) 3363(4) C(2) 2489(6) 7234(6) C(3) 1138 (6) 5447(5) C(4) 335(5) 7036(5) C(5) 1540(4) 6349(4) C(€) 2649(4) 6503 (3) C(7) 3078 (3) 5806(3) C(8) 3547 (4) 6324 (4) C(9) 3918(4) 5595 (4) C(10) 3845 (4) 4354 (4) C(ll) 3385(3) 3874 (3) C(12) 3273 (4) 2556(3) C(13) 2746 (5) 1057 (3) C(14) 4134 (6) 611(5) C(15) 2141(7) 295(5) C(16) 1960(6) 901(4) 1163(1) 2494(3) 2353(6) 1238 (2) 81(1) 434(2) 1021(3) 2326(3) 2489(3) 1493(3) 1874 (2) 676(2) 6(2) -653(2) -1238(2) -1160(2) -487 (2) -327 (2) 662 (3) 943 (4) -55(4) 1357 (4) 47(1) 54(1) 45(2) 54(1) 46(1) 56(1) 70(1) 111(2) 107(2) 106(2) 69(1) 60(1) 53(1) 67 (1) 72(1) 66 (1) 53 (1) 63 (1) 76 (1) 115(2) 126(2) 105(2) 343 Table 4. Anisotropic displacement parameters (A~2 x 10*3) for 1. The anisotropic displacement factor exponent takes the form: -2 pi*2 [ hT2 a*~2 Ull + ... + 2 h k a* b* U12 ] Ull U22 U33 U23 U13 U12 Zr 52(1) 49(1) 42(1) 5(1) 13(1) -2(1) Cl 47 (3) 79(2) 32(2) 14(2) -6(2) -5(2) C 30(4) 73(4) 25(3) 6(3) -19(2) -4(3) Nd) 64(2) 51(2) 48(1) -4(1) 12 (1) 1(1) N(2) 45(1) 53(1) 41(1) 4(1) 5(1) -3(1) N(3) 66(2) 46(1) 56(2) -1(1) 15(1) -4(1) CU) 53(2) 83(3) 74(2) 0(2) 8(2) -3(2) C(2) 126(5) 121(4) 86(3) -49(3) 14 (3) -5(4) C(3) 150 (5) 103 (4) 83(3) -6(3) 67(3) 20(4) C(4) 98 (4) 123(4) 98(3) -14(3) 20(3) 47 (3) C(5) 81(3) 70 (2) 56(2) -12(2) 12 (2) 12(2) C(6) 70 (2) 49(2) 59(2) 3(2) 5(2) -4(2) C(7) 51 (2) 58 (2) 48 (2) 11(1) 2(1) -4 (2) C(8) 65 (2) 72(2) 62(2) 25(2) 3(2) -9(2) CO) 62 (2) 103 (3) 51(2) 23 (2) 13 (2) -3(2) CUO) 62 (2) 93 (3) 46(2) 4(2) 14 (2) 7(2) C(ll) 48 (2) 70 (2) 41(1) 0(1) 9(1) 4(2) C(12) 75 (2) 65 (2) 53(2) -7(2) 18 (2) 3(2) C(13) 92 (3) 49 (2) 88 (3) 3 (2) 16 (2) 0(2) C(14) 124 (5) 80(3) 142 (5) 35(3) 24 (4) 30 (3) C(15) 181 (7) 60 (3) 134(5) -15(3) 12 (5) -33 (3) C(16) 141 (5) 57 (2) 127(4) 24 (3) 60(4) -6(3) 344 Table 5. Hydrogen coordinates (x 10*4) and isotropic displacement parameters (A 2 x 10 3) for 1. U(eq) H(0A) H(0B) H(0C) H(1A) H(1B) H(1C) , H(2A) H(2B) H(2C) HOA) HOB) HOC) H(4A) H(4B) H(4C) H(6A) HOB) . HOA) HOA) H(10A) H(12A) H(12B) H(14A) H(14B) H(14C) H(15A) H(15B) H(15C) H(16A) H(16B) H(16C) 3406(10) 2856(10) 4150(10) -105(4) -401(4) -330(4) 2756(6) 3230(6) 2081(6) 536(6) 738(6) 1888 (6) -267(5) 576 (5) -61 (5) 3372 (4) 1987 (4) 3607(4) 4219 (4) 4102(4) 2697(4) 4114 (4) 4644(6) 4114(6) 4508(6) 2636(7) 1271(7) 2136(7) 2339 (6) 1956(6) 1090(6) 2420(13) 3563(13) 3655(13) 2503(4) 3749 (4) 3661(4) 7811(6) 6800(6) 7650(6) 4875(5) 5874(5) 5025(5) 6477 (5) 7634 (5) 7428 (5) 6952 (3) 7078 O) 7162(4) 5932(4) 3846 (4) 2182(3) 2176(3) 707(5) -228 (5) 1078 (5) 386 (5) 561(5) -542 (5) 1375(4) 62(4) 1168(4) 2386(6) 2780(6) 2407(6) 977(3) 541(3) 1484 (3) 1953(3) 2584(3) 2729(3) 2217(3) 2890 (3) 2747 (3) 1206 (3) 1123 (3) 1909 (3) 959 (2) 462 (2) -695(2) -1688(2) -1553(2) -763 (2) -302 (2) 511(4) 1091(4) 1402 (4) -495 (4) -223(4) 102(4) 1811(4) 1509(4) 1189(4) 67 67 67 105 105 105 167 167 167 161 161 161 158 158 158 72 72 80 86 80 76 76 172 172 172 189 189 189 157 157 157 345 Table 3. Bond lengths [A] and angles [deg] for 1. Zr-N(i) Zr-N(3) Zr-C Zr-N(2) Zr-C(l) Zr-Cl N(l) -C(€) N(l) -C(5) K(2)-C(7) N(2)-C(ll) N{3) -C(12) N(3) -C(13) C(2) -C(5) C(3)-C(5) C(4)-C(5) C(6) -C(7) C(7)-C(8) C(8)-C(9) C(9) -C(10) C(10)-C(ll) C(ll)-C(12) C(13) -CU6) C(13)-C(15) CU3) -CU4) N(l) -Zr-N(3) NU)-Zr-C N (3)-Zr-C NU) -Zr-N(2) N(3)-Zr-N(2) C-Zr-N(2) N{1)-Zr-CU) N(3) -Zr-CU) C-Zr-C(l) N(2)-Zr-C(l) NU) -Zr-Cl N(3) -Zr-Cl N(2) -Zr-Cl CU) -Zr-Cl C(6)-NU)-C(5) C(6)-N(l)-Zr C(5) -NU) -Zr C(7)-K(2)-C(ll) C(7)-N(2)-Zr C(ll)-N(2)-Zr CU2)-N(3)-CU3) CU2)-N(3)-Zr CU3)-N(3)-Zr N(l)-C(5)-C(2) N(l)-C(5)-C(3) C(2)-C(5)-C(3) NU)-C(5)-C(4) C(2)-C{5)-C(4) C(3)-C(5)-C(4) N(l)-C(6)-C(7) N(2)-C(7)-C(8) 2. 099(3) 2 . 105(3) 2. 225 (9) 2. 277 (2) 2. 305(4) 2. 549(4) 1. 462 (4) 1. 497(5) 1. 341(4) 1. 345(4) 1. 452(4) 1. 511(5) 1. 516(7) 1. 530(6) 1. 531(6) 1.478(5) 1 388(5) 1 364(6) 1 .379(6) 1 .387(5) 1 .486 (5) 1 .520(7) 1 .526 (7) 1 .542 (7) 141 .56(10) 102 .2(4) 100 .4(4) 70 .88(10) 70 .69(10) 127 .2 (3) 99.43 (14) 98.45(14) 115.2(3) 117.55 (12) 98.5(2) 101.0(2) 121.64 (13) 120.8(2) 111.9(3) 124.2(2) 123.9(2) 119.9(3) 120.1(2) 120.1(2) 111.8(3) 124.9(2) 123.3(2) 111.4(4) 109.4(3) 107.8(4) 110.3(3) 109.4(4) 108.4(5) 109.9(3) 121.0(4) N(2) - C(7)-C{6) 114 .7(3) C(8)- C(7) -C(6) 124 .3(3) C(9) - C(8)-C(7) 119 .4(4) C(8)- CO) -C(10) 119 .6(3) CO)- C(10)-C(ll) 119 .1(4) N(2)- C(ll)-C(10) 121 .0(3) N(2) - C(ll)-C(12) 114 .7(3) C(10) -C(ll) -C(12) 124 .4(3) N(3) -C{12)-C(ll) 109 .6(3) N(3)- C(13)-C(16) 109 .5(3) N(3)- C(13)-C(15) 110 .8(4) C(16) -C(13)-C(15) 109 .1(5) N(3)- C(13)-C(14) 109 .5(4) CU6) -C(13)-C(14) 108 .4(5) C(15) -C(13)-C(14) 109 .4(5) Symmetry transformations used to generate equivalent atoms: 347 11 Crystallographic data for (iPAP)ZrCl'Pr. Table 1. Crystal data and struc Identification code Empirical formula Formula weight Temperature Wavelength Crystal system Space group Unit cell dimensions Volume, Z Density (calculated) Absorption coefficient F(000) Crystal size Theta range for data collection Limiting indices Reflections collected Independent reflections Absorption correction Max. and min. transmission Refinement method Data / restraints / parameters Goodness-of-fit on F*2 Final R indices II>2sigma(I)) R indices (all data) Largest diff. peak and hole 348 ure refinement for 1. dm006 C16 H28 CI N3 Zr 389.08 296(2) K 0.71073 A Orthorhombic Pbca a - 13.9320(3) A alpha « 90 deg. b * 15.0145(3) A beta - 90 deg. c « 18.2507(2) A gamma • 90 deg. 3817.7(1) A~3, 8 1.354 Mg/irT3 0.714 mm*-l 1616 0.20 x 0.20 x 0.20 mm 2.23 to 25.00 deg. -18c=hc=18, -17<=k<*19, -24<=1<=12 18143 3355 (R(int) = 0.0353] Semi-empirical from psi-scans 0.801475 and 0.724184 Full-matrix least-squares on F"2 3355 / 0 / 190 1.055 RI « 0.0293, wR2 * 0.0624 RI * 0.0433, wR2 « 0.0671 0.285 and -0.338 e.A*-3 349 Table 2. Atomic coordinates ( x 10*4) and equivalent_isotropic displacement parameters (A"2 x 10*3) for 1. U(eq) is defined as one third of the trace of the orthogonalized U13 tensor. U(eq) 2r Cl N(l) N12) N(3) C(l) C{2) C(3) C(4) C(5) C(6) C{7) C(8) C(9) C(10) C(ll) C(12) C(13) C(14) C(15) C<16) €084 (1) 7404(1) 4881(1) 4989(1) €644 (2) 4089(3) 4973 (3) 4903 (2) 4020(2) 4138 12) 3469(2) 3685 (2) 4559 (2) 5200(2) 6180 (2) 7663(2) 7845 (2) 8307(2) 5909(2) 5054(3) 6785(3) 6563(1) 7375(1) 7143(1) 5491(1) 5312(1) 8560(2) 8449 (2) 8120 (2) 6713(2) 5736(2) 5101(2) 4217(2) 3969(2) 4625 (2) 4461(2) 5269 (2) 4678(2) 5001(2) 7066 (2) 6575(2) 7009 (2) 1385(1) 809(1) 944(1) 1045(1) 1557(1) 1317(2) 113(2) 898(2) 673(2) 751(1) 550(2) 642(2) 934(2) 1130(1) 1436(2) 1770(2) 2438(2) 1129 (2) 2542(2) 2868(2) 3039 (2) 32(1) 58(1) 40(1) 38(1) 41(1) 91(1) 79 (1) 50(1) 50(1) 43(1) 56(1) 60(1) 55(1) 42 (1) 51 (1) 48(1) 77 (1) 61 (1) 50(1) 92 (1) 80 (1) 350 Table 3. Bond lengths [A] and angles [deg] for 1. Zr-N(l) 2 .053 (2) Zr-N(3) .2 .059 (2) Zr-C(14) 2 .255(3) Zr-N(2) 2 .304 (2) Zr-Cl 2 .4445(7) N{1) -C(4) 1 .449(3) N(l) -C(3) 1 .470(3) N12) -C(9) 1 .342(3) N(2)-C(5) 1 .353 (3) N(3)-C(10) 1 .449 (3) N(3) -C(ll) 1 .473(3) C(l)-C(3) 1 .518 (4) C(2)-C(3) 1 .520(4) C(4) -C(5) 1 .483 (4) C(5)-C(6) 1 .382(4) C(6)-C(7) 1 .371(4) C(7) -C(8) 1 .380(4) C(8)-C{9) 1 .378 (4) C(9) -C(10) 1 .495 (4) C(ll) -C(12) 1 .529 (4) C(ll)-C(13) 1 .528(4) C(14)-C{16) 1 .523 (4) C(14)-C(15) 1 .523 (4) Nd) -Zr-N(3) 139 .10 (8) Nd) -Zr-Cd4) 97 .86 (9) N(3)-Zr-Cd4) 101 .76(9) Nd) -Zr-N(2) 69 .50(8) N(3) -Zr-N(2) 69 .74(8) C(14)-Zr-N(2) 114 .48(8) N (1)-Zr-Cl 103 .57(6) N (3)-Zr-Cl 103 .63(6) C (14)-Zr-Cl 108 .48(7) N(2)-Zr-Cl 137 .00(5) C(4) -Nd) -C(3) 116 .2 (2) C(4)-N(l)-Zr 128 .4 (2) C (3) -Nd) -Zr 115 .4 (2) C(9)-N(2)-C(5) 120 .2(2) C(9) -N(2) -Zr 120 .0(2) C(5)-N(2)-Zr 119 .8(2) C(10)-N(3)-C(ll) 115 .5(2) C(10)-N(3)-Zr 127 .8(2) C(ll)-N(3)-Zr 116 .4(2) N(l)-C(3)-C(l) 113 .0(2) N(l)-C(3)-C(2) 112 .3(2) C(l)-C(3)-C(2) 112 .4(3) N(l)-C(4)-C{5) 108 .4(2) N(2)-C(5)-C(6) 120 .5(3) N(2) -C(5) -C(4) 113 .8(2) C(6)-C(5)-C(4) 125 .6(3) C(7)-C(6)-C(5) 119 .2(3) C(6)-C(7)-C(8) 120 .2(3) C(9)-C(8)-C(7) 118 .6(3) N(2) -C(9) -C(8) 121 .3(3) N(2)-C(9)-C(10) 113 .8(2) C(8)-C(9)-C(10) 124 .8(3) N(3) -C(10) -C(9) N(3) -C(ll) -C(12) N(3) -C(ll) -C(13) C(12)-C(ll)-C(13) C(16)-C(14)-C(15) C(16)-C(14)-Zr C(15)-C(14)-Zr 108.5 (2) 113.3 (2) 112.1(2) 111.1 (2) 111.5 (3) 116.9 (2) 106 .7 (2) Symmetry transformations used to generate equivalent atoms: 352 Table 4. Anisotropic displacement parameters (A*2 x 10 3) The anisotropic displacement factor exponent takes the form: -2 pi "2 [ h~2 a**2 Ull + ... + 2. h k a* b* U12 .] Ull U22 U33 Zr 31(1) 30(1) 37(1) CI 46 (1) 44 (1) 83(1) N(l) 35 (1) 42 (1) 43(1) N(2) 37 (1) 42 (1) 34 (1) N(3) 43 (1) 32 (1) 47 (1) C(l) 70 (2) 61 (2) 141 (4) C(2) 96(3) 57 (2) 84 (3) C(3) 44 (2) 43 (2) 62 (2) C(4) 35 (1) 61 (2) 53 (2) C(5) 36 (1) 58 (2) 34 (1) C(6) 41 (2) 79 (2) 48(2) C(7) 60 (2) 67 (2) 53 (2) C(8) 66(2) 44 (2) 55 (2) CO) 49 (2) 39 (1) 38 (1) C(10) 57 (2) 35 (1) 60 (2) C(ll) 46 (2) 39 (2) 57 (2) C(12) 79 (2) 76 (2) 76 (2) C(13) 42 (2) 53 (2) 87 (2) C(14) 56 (2) 51 (2) 45 (2) C(15) 99 13) 116 (3) 59 (2) C(16) 83 (2) 88 (3) 67 (2) U23 U13 U12 0(1) -1(1) -4 (1) 6(1) 18 (1) -9 (1) 1(1) -4 (1) -1(1) -2 (1) 3 (1) -9(1) 2 (1) -3 (1) -2 (1) 20 (2) 10 (2) 17(2) 27 (2) -24 (2) -6(2) 0(1) -8 (1) 6(1) -2 (1) -5(1) -1(1) -4 (1) 3 (1) -10(1) -9 (2) -1 (1) -20 (2) 17 (2) 8 (2) -34 (2) -7 (1) 14(2) -20 (2) -3 (1) 8 (1) -12 (1) 3 (1) 0 (1) -4 (1) 2 (1) -11 (1) 2 (1) 22 (2) -25 (2) 4 (2) -7 (2) 0 (2) 6(1) -8 (1) -3 (1) -2 (1) •11 (2) 20 (2) -34 (2) •21 (2) -20 (2) 13 (2) 353 Table 5. Hydrogen coordinates ( x 10*4) and isotropic displacement parameters (A~2 x 10*3) for 1. x U(eq) H(1A) H(2A) H(3A) H(2A) H(2B) H(2C) H(3A) H(4A) H(4B) H(6A) H(7A) H(8A) H(10A) H(10B) H(11A) H(12A) H(12B) H(12C) H(13A) H(13B) H{13C) H(14A) H(15A) HU5B) HU5C) H(16A) H(26B) H(16C) 4073 (3) 3491 (3) 4190(3) 5495(3) 5084 (3) 4385 (3) 5497 (2) 3919 (2) 3467(2) 2880(2) 3242 (2) 4711 (2) 6132 (2) 6554 (2) 7851(2) 7430(2) 6502(2) 7716 (2) 8178(2) 8180 (2) 8968 (2) 5731 (2) 4514 (3) 4893 (3) 5214(3) 7309 (3) 6961 (3) 6636 (3) 8333 (2) 8434 (2) 9193 (2) 8153 (2) 9080 (2) 8321 (2) 8307 (2) 6866 (2) 6912 (2) 5271 (2) 3784 (2) 3371 (2) 4136(2) 4106 (2) 5874 (2) 4858 (2) 4737 (2) 4068 (2) 5379 (2) 4393 (2) 5061 (2) 7696(2) 6625 (2) 6832 (2) 5958 (2) 7327 (2) 6396 (2) 7268 (2) 1808 (2) 1078(2) 1329 (2) -130 (2) 112 (2) -140 (2) 1141 (2) 163 (2) 951(2) 356 (2) 506 (2) 998 (2) 1894(2) 1095 (2) 1910 (2) 2831 (2) 2589 (2) 2313 (2) 717 (2) 998 (2) 1270 (2) 2509(2) 2543 (2) 3333 (2) 2932 (2) 2820 (2) 3105(2) 3507 (2) 109 109 109 95 95 95 60 59 59 67 72 66 61 61 57 116 116 116 91 91 91 60 137 137 137 119 119 119 354 12 Crystallographic data for (BDPP)TaCI(ri2-oct-4-yne). 355 Table Sl. Crystal Data and Experimental Details. Empirical formula Formula weight Temperature Wavelength Crystal system Space group Unit cell dimensions Volume Z Density, calcd. Absorption coefficient F'(OGG) Reflections Collected Independent reflections Refinement method Data/restraints/parameters Goodness-of-fit (GooF) on F2 Final R indices [I>2sigma(I)] R indices (all data) C39H65C^N3Ta1 792 .36 23°C 0.71073 A Triclinic PI a = 9.936 (2)A b = 11.558 (1)A c = 17.689 (2)A a = 74.997 (6) 0 j8 = 87 . 424 (10) 0 7 = 75.372 (9) 0 18 58.0(5) A: 2 1.386 g.cm"3 2 . 555 mm"1 820 6078 517S . [R(int) = 0 . 0284] Full-matrix least - squares on F2 5179/90/408 1 . 037 RI = 0.0401, wR2 = 0.0946 RI = 0.0519, wR2 = 0.1011 RI = r(||F0|-|Fc||)/Z|F0|; wR2 = [Ew(F02 - Fc2)2/EwFD4]1/2 GooF = [Iw(F02 - Fc2)2/(n-p)]1/2 where n is the number of reflections and p is.the number of parameters refined. 356 Table £2. Atomic coordinates ( x 10\) and equivalent isotropic displacement parameters (A2 x 103). U(eq) is defined as one third of the trace of the orthogonalized Uij tensor. atom X y z Ueq Ta (1) 2183 . 0 (3) 2065 6(3) . 7998 6 (2) 33 . 1 (1 CI (1) 3823 .2) 573 (2) . 8902 (1) 60 ( 1) N (1) 1164 (6) 3359 (5) 8572 (3) 37 ( 1) C(l) 1591 (8) 4434 (6) 8626 (4) 39 ( 2) C(2) 2398 (8) 4353 (7) 9276 (5) 45 ( 2) C(3) 2773 (10) 5399 (8) 9339 (5) 61 ( 2) C(4) 2383 (12) 6499 (8) 8792 (5) 75 ( 3) C(5) 1597 (11) 6566 (7) 8157 (5) 67 ( 3) C(6) 1197 (9) 5552 (7) 8049 (4) 48 ( 2) C (7) -15 (8) 3232 (7) 9086 (4) 46 ( 2) N(2) 346 (6) 1452 (5) 8610 (3) 38 ( 1) C (6) -436 (8) 2078 >7) 9089 (4) 47 ( 2) C (9) -1532 (9) 167S (9) 9483 (5) 61 2) C (10) -1601 (10) 629 (S) 9379 (5) 70 3) C (111 -1043 (10) 24 (9) 8872 (5) 66 3) C ;I2) 34 O) 448 (7) 6487 (5) 47 2) C(13) 919 (9) -23 (7) 7874 (5) 57 2) N(3) 1675 (6) 879 (5) 7456 (3) 42 2) C (14) 2003 (8) 699 (7) 6682 (4) 42 2) C (15) 972 (10) 1276 (8) 6083 (5) 60 2) C -;i6; 1^47 12; 112 3 (10; 5336 (6) 79 3) C (17) 2631 in) 43 6 (11) 5188 (6) 82 3) C (18) 3567 di) -142 (9) 5780 (6) 70 3) C (19) 32 6 0 O) -53 (8) 6544 (5) 56 2.) C (20) 2S25 (7) 3157 (7) 9898 (4) 49 2) C (21) 4518 (7) 2765 (9) 9945 (6) 85 3) C (22) 2351 (9) 3251 (9) 10705 (4) 75 3) C (23 ) 346 (6) 5707 (7) 7325 (4) 62 3) c (24; 1045 (11) 6236 (10) 6570 (5) 99 4) C(25) -1130 (9) 6518 (10). 7344 (6) 100 4) C(26) 4350 o; -762 (6) 7183 (5) 63 3) C (27) 5639 O) -251 (8) 7133 (6) 83 3) C(28) 4791 (12) -2149 (7) 7234 (7) 101 4) C (29) -476 (9) 2035 (8) 6226 (5) 72 3) COO) -1572 (53) 1505 (51) 5947 (39) 94 20) C(31) -771 (76) 3428 (19) 5845 (45) 94 20) C (30A) -1496 (36) 1248 (32) 6198 (26) 87 12) C(31A) -1002 (45) 3330 (18) 5682 (25) 87 12) C(30B) -1643 (39) 1801 (39) 5792 (28) 83 14) C(31B) -463 (54) 3406 (16) 5940 (33) 83 14) C(32) 3559 (8) 3116 (8) 7526 (5) 59 2) C(33) 4530 O) 3933 O) 7569 (7) 96 4) C(34) 6025 (9) 3252 (11) 7634 (8) 121 5) C (35) 6931 (11) 4095 (13) 7659 (9) 148 7) C (36) 2943 (8) 2957 (7) 6951 (4) 49 2) C (37) 2932 O) 3376 (10) 6061 (4) 77 3) C (38) 4336 (10) 3205 (14) 5718 (5) 119 5) C(39) 4258 (13) 3554 (12) 4845 (5) 111 5) 357 Table S3. Bond Distances (A) and Angles (°) Ta (1) Ta (1) Ta (1) N(l) -C(l) -C(2) -C(3) -C(5) -C(7) -N(2) -CO) -C(ll) C(13) C(14) C(15) C(16) C (18) C (20) C(23) C (26) C (25) C (25) C (25) C (3C^ C (32) COS) C(36) C(38) -NO) -C (32) -N (2) C(l) CO) CO) C(4) CO) C(8) CO) C (10) -C(12) -NO) -C(19) -C(16) -C(17) -C (19) -C (22) - C (2 5 ) -C127) -C(31A) -COD -C(3 OB) ^ _ Q i -3 n D ) C (36) C (34) C(37) COS) 2 . 033 (6) Ta(1) -N (1) 2 . 053 (6) 2 . 062 (7) Ta(1)-C(36) 2 . 085(7) 2 . 255 (6) Ta(1)-Cl(1) 2 . 361 (2) 1. 436 (9) N(l) -C(7) 1. 463(9) 1 . 401 (10) C(l) -C(2) 1 . 401 (10) 1 . 383 (11) C(2) -C(20) 1. 515 (10) 1 . 361(11) C(4) -C(5) 1 . 370 (12) 1. 388(11) C(6) -C(23) 1 . 512(11) 1 494 (11) N(2) -C(12) 1. 345 (9) 1 348 (9) CO) -co) 1 379(11) 1 365 (12) C(10)-C(ll) 1 363(12) 1 369 (11) C(12)-C(13) 1 491(11) 1 464(9) NO) -C(14) 1 449(9) 1 396(11) C(14) -C(15) 1 415 (11) 1 399 (12) C (15) -C (29) 1 532 (12) 1 376 (14) C(17)-C (18) 1 .348 (14) 1 393 (11) C(19) -C(26) 1 . 506 (12) 1 532(5) C (20) -C (21) 1 .532 (5) 1 .533 (5) C(23) -C(24) 1 .533(5) 1 .530 (5) C(26) -C(28) 1 .531(5) 1 .531 (6) C (29) -C (30) 1 .533 (6) 1 .533 (6) C (25) -C O0A) 1 .533(6) 1 .534 (6) C(29)-C(31B) 1 .536(6) 0 .82 (6) C(31A)-C(31B) 0 .76(5) .287 (11) C(32)-C(33) 1 .527 (9) 1 .469 (8) C(34) -C(35) 1 .454(8) 1 .522 (8) C (37)-C(38) 1 .483(8) 1 .452(8) NO)-Ta (1)-N(D 137.2(2) N (3 )-Ta (1) - C (32 ) 122.1(3) N (1) - Ta (1) - C (32 ) 91.5(3) N (3)-Ta (1)-C (3 6 ) 90.0(3) N(l)-Ta(D-C{36) 105.2(3) C (32)-Ta (1) - C (36 ) 36.2(3) NO)-Ta (1)-N{2) 71.9(2) N (1)-Ta (1)-N (2) 71.4(2) C(32)-Ta (1)-N(2) 162.6(3) C (3 6 )-Ta (1)-N (2 ) 146.2(3) NO)-Ta (1)-CI (1) 56.5(2) N (1)-Ta (1)-Cl (1) 106.6(2) C(32)-Ta(1)-Cl (1) 94.5(3) C(36)-Ta(1)-Cl(1) 117.1(2) N(2) -Ta (1)-Cl (1) 93.7(2) C(l)-N(l)-C(7) 108.7(5) C(l)-N(l)-Ta(l) 126.3(5) C (7)-N (1)-Ta (1) 124.5(5) C(6)-C(l)-C(2) 120.1(7) C(6)-C(l)-N(l) 121.1(7) C(2)-C(l)-N(l) 118.8(6) CO)-C(2)-C(l) 118.7(7) CO)-C(2)-C(20) 118.4(7) C (1)-C (2)-C (20) 122.8(7) C(4)-C(3)-C(2) 122.1(8) C (3)-C (4)-C (5) 118.7(8) C(4)-C(5)-C(6) 122.4(8) C (5)-C (6)-C (1) 117.9(7) C(5)-C(6)-C(23) 118.8(7) C (1)-C (6 )-C (23 ) 123.2 (7) N(l)-C(7)-C(8) 110.6(6) C(12) -N(2)-CO) 120.2(7) C(12)-N(2)-Ta (1) 118.8(5) C(8)-N(2)-Ta(1) 121.0(5) N(2) -CO)-CO) 121.0(8) N(2)-CO)-C(7) 112.1(7) C(9)-C(8)-C(7) 126.8(8) C(10)-C(9)-C(8) 118.3(8) C(ll) -C(10)-CO) 120.6(8) C(10)-C(ll)-C(12) 119.6(9) N(2)-C(12)-C(ll) 120.2(8) N(2)-C(12)-C(13) 111.7(6) C(U)-C(12)-C(13) 127.9(8) N (3 ) - C (13 ) - C (12 ) 110.6(6) C(14)-N(3)-C(13) 109.3(6) C(14)-N(3)-Ta(1) 130.2(5) 358 C(13) - KM 3) -Ta (1) 120 . 4 (5) C(19) - C(14) -N(3) 120 . 6 (7) C(16) - C(15)-C(14) 116 . 1(9) C (14.) - C (15) -C (29) 123 0 (7) C(18) - C(17)-C(16) 119 7 (9) C(18) - C(19) -C(14) 118 1(9) C(14) - C(19) -C(26) 122 8 (7) C(2) -C(20) -C(21) 111 6 (7) C(6) -C (23)-C(25) 112 1 (7) C(25) - C(23) -C (24) 109 4 (5) C (19) - C (26) -C (28) 112 9(8) C(31A) -C(29)-C(15) 118 (2) COO)- C (29) -C (31) 109 7(6) C (31A) -C(29) -C(30A) 109 7 (6) C(15) - C(29) -C(30B) 113 (2) C (30B) -C (29) -C (31B) 109 .1(6) C(36) - C(32)-Ta(1) 72 .9 (4) C(34) - C(33)-C(32) 112 . 9(7) C(32) - C ( 3 6 ) - C (3 7 ) 137 2 (8) C ( 3 7 ) -C(36) -Ta '1! 151 .7(6; C(37) - C (36) -C (39 ) 111 .7(6) C(19) -C(14) -C(15) 121 . 6 (7) C(15) -C(14) -N(3) 117 . 7 (7) C(16) -CC15) -C (29) 120 . 9(9) C(17) -C(16) -C(15) 122 . 5 (10) C(17) -C(18) -C(19) 121 8 (9) C(18) -C(19) -C(26) 119 1(8) C(2) - C(20) - C(22) 111 8 (6) C(22) -C (20) -C(21) 109 7 (5) C(6) - C(23) - C (24) 112 3 (7) C(19) -C(26) -C(27) 113 7 (7) <C(27) -C(26) -C(28) 109 .8(5) COO) -C (29) -C(15) 109 (3) C(15) -C (29) -COD 115 O) C(15) -C (29) -C (30A) 107 (2) C(15) -C (29) -C(31B) 107 (2) C(36) -C(32) -C(33) 132 .6(8) C (33) -C(32) -Ta(1) 153 .3 (7) C(33) -C(34) -C (35) 110 .8(8) C (32) -C(36) -Ta(1) 71 .0(4) C(38) -C(37) -C(36) 114 .1 (7) 359 Table £4. Anisotropic displacement parameters (A2 x 103). The anisotropic displacement factor exponent takes the form: -2TT2 [h2a*2Ull + ... + 2hka*b*U12] U13 U12 atom Ull U22 U33 U23 Ta (1) 35 (1) 31 (1) 34 (1) -10 (1) CI (1) 60 (1) 54 (1) 51 (1) -6 (1) N(l) 37 (4) " . 39(3) 36 (3) -11 (3) C(l) 44 (5) 34 (4) 41 (4) -15 (3) C(2) 47 (5) 36 (4) 55 (5) -16 (4) C(3) 73 (7) 57 (5) 59 (5) -19 (4) C(4) 128 (10) 41 (5) 70 (6) -19 (5) C(5) 104 (8) 28 (4) 62 (6) -4 (4) C(6) 60 (5) 40 (4) 45 (5) -12 (4) C(7) 46(5) 54 (5) 41 (4) -24 (4) N(2) 41(4) 41 (3) 34 (3) -12 (3) C {6; 4 3(5) 57 (5) 39 (4) -9 (4) C(9) 54 (6) 82 (7) 50(5) -21 (5) C (10 ) 70 (7) 90 (7) 61 (6) -13(5) C (11) 66 (6) 68 (6) 65 (6) -10(5) C (12) 56 (5) 3 7(4 ) 50 (5) -7 (4) C (13) 66(6) 36 (4) 75 (6) -20 (4) N(3) 45(4) 37 (3) 47 (4) -15 (3) C'14) 49(5) 4 6(4) 4 3(4) -24(4) C (15) 64 (6) 72 (6) 55 (5) -33(5) C (16) 80(8). 111(9) 63(6) -41 (6) C (17) 73 (7) 134 (10) 64 (6) -69 (7) C (18) 61(6) 6 9(7) 7 6^7) -49(6) C (IS) 61 {6 ) 54 (5) 59 (5) -27(4) C (20) 59(6) 43 (4) 46 (5) -8 (4) C(2i) 69(7) 76 (7) 100(8) -18(6) C(22) 98 (S ) 80(7) 51 (5) -18 (5) C(23) 56 (7 ) 40 (5) 47 (5) -4 (4) C (24 ) 129 (11) 102 (6) 48(6) -6 (6) C (25) 80(6) 115 (S) 93 (8) -39 (7) C (26) 65 (6) 52 (5) 66 (6) -16 (4) C (27) 69 (7) 83 (7) 93 (8) -16 (6) C (28) 114 (10) 59 (6) 127 (10) -35 (7) C (29) 45 (6) 106 (8) 78 (7) -47 (6) C(32) . 64 (6) 78 (6) 53 (5) -22 (5) C(33) 97 (9) 134 (11) 80(8) . -42 (7) C (34 ) 99 (11) 155 (13) 95 (9) -38(9) C(35) 97(11) 167 (16) 192 (16) -39 (13) C(36) 53 (5) 55 (5) 45 (5) -19 (4) C(37) 73 (7) 107 (8) 46(5) -13 (5) C (38) 97 (10) 200 (15) 52 (6) -20 (8) C(39) 135(12) 150 (12) 59 (7) -28 (7) 6(1) -9(1) -6(1) 5(1) 5(3) -11(3) 9(4) -6(3) •11(4) -8(4) •13(5) -20(5) •12(6) -37(6) -6(6) -10(5) -9(4) -7(4) 7(4) -10(4) 10(3) -13(3) 0(4) -14 (4) 21(4) -24(5) 28(5) -51(6) 18(5) -36(5) 13(4) -22(4) '9(5) -18(4) 11(3) -16(3) 12 (4 ) -23(4) 2(5) -22(5) -1(6) -33 (7) 20(6) -27(7) 21(6) -18(6) 23(5) -15(5) -10(4) -15(4) -31(6) -3(6) -8(5) -27(6) -13(5) -1(5) -5(7) -8(8) -24(7) 13(7) 23(5) -7(5) 1(6) -19(6) 41(8) -14(7) -3(5) -14(5) 15(5) -47(5) 23(7) -58(8) -4(8) -1(10) -33(10) -98(11) 8(4) -21(4) 7(5) -22(6) 19(7) -39(10) 43(7) -58(10) 360 Table £5. Calculated Hydrogen Atom Coordinates (X IO4) Parameters (x 103) atom x y y Ueq H(3) 3310 (10) 5348 (8) 9765 (5) 73 H (4) 2644 (12) 7191 (8) 8847 (5) 90 H(5) 1320 (11) 7320 (7) 7786 (5) 80 H(7A) -794 (8) 3943 (7) 8907 (4) 55 H (7B) 240 (8) 3207(7) 9614 (4) 55 H(9) -2073 (9) 2115 (9) 9810 (5) 73 H(10) -2509 (10) 323 (9) 9657(5) 84 H(ll) -1255 (10) -672 (9) 8789 (5) 79 H(13A) 1578 (9) -796 (7) 8117 (5) 68 H(13B) 339(9) -184 (7) 7506 (5) 68 H (16) 704(12) 1500 (10) 4925 (6) 95 H (17) 2853 (11) 371 (11) 4682 (6) 99 H (18) 4427 (11) -614 (9) 5675 (6) 84 H (20) 2599 (7) 2508(7) 9754 (4) 59 H (21A) 4816 (7) 2003(37) 10341(30) 128 H ( 2 IB) 4863 (8) 3395 (32) 10075(42) 128 H (21C) 4872 (8) 2651 (66) 9449 (14) 128 H(22A) 2719 (57) 3633 (45) 10679 (18) 112 H(22E) 2621 (62) 2455 (17) 11071 (10) 112 H (2 2 C) 1355 (10) 3525 (62) 10670 (10) 112 H (23) 266 (8) 4865 (7) 7311 (4 ) 74 H(24A) 1962 (31) 5747(50) 6567 (24) 149 K(24B; 1056(82) 7074(23) 6543 (25) 149 H (24C) 534 (53) 6215 (74) 6127 (5) 149 H(25A) -1634 (30) 6551(66) .6877 (24) 150 K(25B) -1063(9) 7325 (26) 7374 (50) 150 H (25C) -1597 (31) 6147 (41) 7753 (28) 150 H (26) 3 5 0 8(8) -675 (6) 7678 (5) 75 H(27A) 6286 (34) -754 (40) 7547 (26) 124 H(27B) 5370 (14) 563 (24) 7185 (42) 124 H (27C) 6068 (43) -262 (62) 6637 (18) 124 H (28A) 5348(75) -2573 (12) 7700(28) 151 H USE) 5322 (78) -2283 (9) 6784 (27) 151 H (28C) 3978 (12) -2460 (17) 7250 (51) 151 H(33A) 4385 (9) 4618 (9) 7103 (7) 115 H(33B) 4295 (9) 4274 (9) 8018 (7) 115 H (34A) 6266 (9) 2901 (11) 7189 (8) 145 H(34B) 6163 (9) 2578 (11) 8105(8) 145 H (35A) 6755 (91) 4775 (60) 7199 (36) 221 H(35B) 7891 (11) 3648 (32) 7676(71) 221 H (35C) 6732 (88) 4404 (88) 8116 (39) 221 H(37A) 2411 (9) 2918 (10) 5853 (4) 92 H(37B) 2450(9) 4244 (10) 5897 (4) 92 H(38A) 4846 (10) 2347 (14) 5902(5) 143 H(38B] 4841 (10) 3709 (14) 5893(5) 143 H(3 9A) 5180 (15) 3376 (83) 4643 (5) 167 H(39B) 3830 (92) 4422 (22) 4659 (5) 167 H (39C) 3715 (85) 3090 (66) 4671 (5) 167 361 Table 1. Crystal data and structure refinement for 1 362 Identification code Empirical formula Formula weight Temperature Wavelength Crystal system Space group Unit cell dimensions Volume, Z Density (calculated) Absorption coefficient F(000) Crystal size Theta range for data collection Limiting indices Reflections collected Independent reflections Absorption correction Refinement method Data / restraints / parameters Goodness-of-fit on F*2 Final R indices [I>2sigma(I) ] R indices (all data) Extinction coefficient Largest diff. peak and hole dm002 C58 H73 N3 Ta 993.14 293(2) K 0 .71073 A Monoclinic P2(l)/c a = 13.530(2) A b = 18.389(2) A c = 21.604 (3) A alpha = 90 deg. beta = 102.98 (1) deg. gamma =90 deg. 5238(1) A~3, 4 1.259 Mg/m"3 2 .136 mirT-1 2060 0.10 x 0.10 x 0.10 mm 1.47 to 21. 00 deg. -17c=h<=17, -ll<=k<=23, -28<=lc=27 18018 5624 [R(int) = 0.0902] None Full-matrix least-squares on F~2 5575 / 3 / 500 1.230 RI = 0.0794, wR2 = 0.1458 RI = 0.1099, wR2 = 0.1593 0.0033(3) 0.667 and -0.634 e.A~-3 363 Table 2. Atomic coordinates ( « «« ^^of ii'SfiS* S'Si'SSS "TS'Se^ei ?he°orU=|onaii,eo BiJ tensor. U(eq) Ta C(l) N(l) C(2) N(2) C(3) C(4) C(5) C(6) C(7) C(8) C(ll) C(12) C(13) C{14) C(15) N(16) 0(21) C(22) C(23) C(24) C(25) C(26) C(31) C(32) C(33) C(34) C(35) 0(36) C(41) 0(42) 0(43) 0(44) 0(45) 0(46) 0(51) 0(52) 0(53) 0(54) 0(55) 0(56) 0(61) 0(62) 0(63) 0(64) 0(65) 0(66) 0(211) 0(212) 0(213) -2885(1) -1329(10) -3131(8) -1575(9) -3284 (7) -1135(10) -1777(12) -2907(11) -3457(10) -4135(11) -4352(10) -4855 (7) -5792 (7) -6307 (6) -5886 (7) -4949 (7) -4434(5) -2156(8) -1437 (9) -92B (7) -1137 (8) -1856 (9) -2366(6) -2237 (8) -1629 (7) -1441(6) -1860(8) -2468 (7) -2656 (6) -37(8) 857(9) 1433(7) 1113(9) 219(9) -356(6) -5128(11) -6175(10) -6667(6) -6111(11) -5065(11) -4573(6) 18(12) 442(12) 1602(14) -1465(12) -1402(13) -1063(17) -2708(14) -2016(17) -3538(14) 5671(1) 5602(7) 6643 (6) 5336(7) 5147(6) 4920(8) 4553(8) 4559(7) 4910(8) 6965(9) 5105(8) 6657(5) 6916(5) 6564(6) 5953(6) 5694 (4) 6046 (5) 7075(5) 7540(7) 8033(6) 8061(6) 7596(6) 7103(5) 5111(4) 4742(7) 4004 (7) 3635(4) 4004 (5) 4742(5) 5106(5) 5175(6) 5806(8) 6368(6) 6299(5) 5668(7) 5304(7) 5233(8) 4661(10) 4159(8) 4230(7) 4802(8) 4891(9) 5597(12) 5633(14) 4080(8) 3290(9) 2828(11) 6576(9) 6138(12) 6960(11) -2871(1) -2786(6) -2512(5) -2265(6) -3704(5) -1723(7) -1457(7) -1731(7) -2255(7) -2588 (8) -4075(7) -3126(4) -3455 (5) -4002 (5) -4221(4) -3892 (4) -3345 (4) -1474 (5) -1119 (5) -1423 (7) -2082(7) -2438(5) -2134 (5) -4481(5) -4817 (4) -4713 (5) -4272 (5) -3935(4) -4040 (4) -3337 (5) -3546(5) -3418(6) -3079(6) -2870(5) -2998(4) -2090(6) -2190(8) -2554(8) -2818(6) -2718(6) -2354(6) -1495(8) -1212(9) -1080(13) -853(7) -1016(9) -413(11) -1120(8) -564(9) -869(10) 51(1) 54(3) 60(3) 49(3) 50(3) 59(4) 70(4) 65(4) 63(4) 84 (5) 72(4) 67(4) 83 (5) 86(5) 76(5) 64 (4) 55(3) 72(4) 98(6) 127 (8) 113(7) 82(5) 63 (4) 59 (4) 78 (5) 91(6) 75(5) 57(4) 57(4) 68(4) 90(5) 99(6) 99(6) 84(5) 56(3) 123(7) 175(12) 155(11) 134(9) 108(6) 76(5) 84(5) 115(7) 191(12) 81(5) 107(6) 160(10) 93(6) 143(8) 127(7) 364 C(251) C(252) C(253) C(311) C(312) C(313) C(351) C(352) C{353) C(93) C(92) C(91) •2036(17) •2932(18) •1138(17) •2390 (14) •3173(18) -1428(14) -2903(12) -2093(16) -3647(16) -5486(33) -5709(30) -4983(55) 7640(10) 8051(20) 7912(11) 5930(8) 6058 (13) 6339(10) 3607(7) 3270(10) 3000(11) 8521(29) 9159(27) 9641(11) •3169 (10) -3492 (12) •3394 (12) •4616(9) •5234(14) -4634 (9) -3444 (8) -2933(9) -3766(11) -4598(24) -4901(29) -4939(28) 110(7) 238 (19) 167(10) 89(5) 224 (17) 127 (8) 78(5) 126(7) 152(9) 358(37) 351(37) 356(44) Table 3. Bond lengths [A] and angles [deg] Ta-N(2) Ta-N(l) Ta-C(2) Ta-C(l) Ta-C(6) Ta-N(16) C(l)-C(2) C(l)-C(46) N(l)-C(7) N(l)-C<26) C(2) -C(3) N(2) -C(36) N(2)-C(8) C(3) -C(4) C(3)-C(61) C(4)-C{5) C(4) -C(€4) C(5) -C(6) C(6)-C(56) C{7)-C(ll) C(8) -C(15) C(ll)-C(12) C(ll)-N(l€) C(12) -CU3) C(13) -C(14) C(14)-C(15) C(15)-N(16) C(21)-C(22) C(21) -C(26) C(21)-C(211) C(22)-C(23) C(23)-C(24) C(24)-C<25) C(25)-C(26) C(25)-C(251) C(31)-C(32) C(31)-C(36) C(31)-C(311) C(32)-C(33) C(33) -C(34) C(34)-C(35) C(35)-C(36) C135)-C(351) C(41)-C(42) C(41)-C(46) C(42)-C(43) C(43)-C(44) C(44)-C(45) C(45) -C(46) C(51)-C(52) C(51)-C(56) C(52)-C(53) C(53)-C(54) C(54)-C(55) C(55)-C(56) C(61)-C(62) 1 1. 1 1 1, 1 1 1 1 1 1. 2.005(10) 2.006(11) 2.030(12) 2.075(14) 2.19(2) 2.225(6) 1.30(2) 1.49(2) 1.46(2) 1.440(12) 1.45(2) 1.442(12) 1.49(2) 1.33(2) 1.53(2) 1.51(2) 1.55(2) .37 (2) .49(2) .45(2) .46(2) .39 .39 .39 .39 .39 .39 .39 1.39 1.50(2) 1.39 1.39 1.39 1.39 1.55(2) .39 .39 .54(2) .39 1.39 1.39 1.39 1.51(2) 1.39 1.39 1.39 1.39 1.39 1.39 1.39 1.39 .39 .39 .39 .39 .49(2) 1 1. 1. 1 1 1, 1 1. 1 C(62)-C(63) C(64)-C(65) C(65)-C(66) C(211)-C(213) C(211)-C{212) C(251) -C(252) C(251)-C(253) C(311)-C(313) C(3ll)-CJ312) C(351)-C(352) C(351)-C(353) C(93)-C(92) C(92)-C(91) C(91)-C(91)#l N(2)-Ta-N{l) N(2)-Ta-C(2) N(l)-Ta-C{2) N(2) -Ta-C(l) NU) -Ta-CU) C{2) -Ta-CU) N(2)-Ta-C(6) N(l)-Ta-C(6) C{2)-Ta-C(6) CU) -Ta-C(6) N(2) -Ta-NU6) NU) -Ta-N(l6) C(2) -Ta-NU6) CU) -Ta-N(16) C(6)-Ta-N(16) C(2) -CU) -C(46) C(2) -CU) -Ta C(46) -CU) -Ta C(7) -NU) -C(26) C(7) -NU) -Ta C(26) -NU) -Ta CU) -C(2) -C(3) CU) -C(2) -Ta C(3)-C(2)-Ta C(36) -N(2) -C(8) C(36)-N(2)-Ta C{8)-N(2)-Ta C(4) -C(3) -C(2) C(4)-C(3)-C(61) C(2)-C(3)-C(61) C(3)-C(4)-C(5) C(3)-C(4)-C(64) C(5)-C(4)-C(64) C(6)-C(5)-C(4) C(5)-C(6)-C(56) C{5)-C(6)-Ta C(56)-C(6)-Ta NU)-C(7)-C(11) CU5)-C(8)-N(2) CU2)-C(11)-N(16) C (12)-C(ll)-C(7) N(16)-C(ll)-C(7) C (13) -CU2) -CUD C(14)-C(13)-C(12) CU5)-C(14)-C(13) 1. 53(2) 1. 50(2) 1. 54(2) 1. 52 (2) 1. 57(2) 1. 46(3) 1. 49(2) 1. 51(2) 1. 52(2) 1. 50(2) 1. 56(2) 1. 35(4) 1. 34 (4) 1. 35(4) 137. 9(4) 115. 8(5) 103. 1(5) 96. 5(4) 105. 9 (5) 36. 8(5) 100 2 (5) 102 8(5) 78 7 (5) 113 3 (5) 72 6 (4) 71 4 (4) 169 0(4) 153 .1 (4) 93 .0(4) 134 .1(12) 69 .7(8) 156 .1(9) 111 .0 (10) 123 .3(8) 125 .6(7) 140 .0(13) 73 .5(8) 145 .3(10) 108 .3 (9) 129 .0(7) 122 .7(8) 116 .4(12) 124 .3(14) 119 .2(13) 122 .1(13) 124 .7(14) 113 .3(13) 129 .9(13) 113 .6(13) 127 .2(10) 118 .9(10) 111 .9(12) 110 .3(10) 120 .0 130 .2(9) 109 .5(9) 120 .0 120 .0 120 .0 C(14)-C(15)-N(16) C(14)-C(15)-C(8) N(16)-C(15)-C(8) C(15)-N(16)-C(ll) C(15)-N(16)-Ta C(ll)-N(16)-Ta C{22)-C(21)-C(26) C(22)-C(21)-C(211) C(26) -C(21) -C(211) C(21)-C(22)-C(23) C(24),-'C(23) -C(22) C(23)-C(24) -C(25) C(26)-C{25)-C(24) C(26)-C(25)-C(251) C(24)-C(25)-C(251) C(25) -C(26) -C(21) C(25)-C(26)-N(l) C(21) -C(26) -N(l) C(32)-C(31)-C(36) C(32)-C(31)-C(311) C(36)-C(31)-C(311) C(31)-C(32)-C(33) C(32)-C(33)-C(34) C(35)-C(34)-C(33) C(36)-C(35)-C(34) C(36)-C(35)-C(351) C(34)-C(35)-C(351) C(35)-C(36)-C(31) C(35) -C(36) -N(2) C(31) -C(36) -N(2) C(42)-C(41)-C(46) C(43) -C(42) -C(41) C(42) -C(43) -C(44) C(45)-C{44)-C(43) C(46)-C(45)-C(44) C(45)-C<46)-C(41) C(45) -C(46) -C(l) C(41) -C(46) -C(l) C(52)-C(51)-C{56) C(51)-C(52)-C(53) C(52)-C(53)-C(54) C(55)-C(54)-C(53) C(56)-C(55)-C(54) C(55)-C(56)-C(51) C(55)-C(56)-C(6) C(51)-C(56)-C(6) C(62)-C(61)-C(3) C(61)-C(€2)-C(63) C(65)-C(64)-C(4) C(64)-C(65)-C(66) C(21)-C(211)-C(213) C(21) -C(211) -C(212) C(213)-C(211)-C(212) C(252)-C(251)-C(253) C(252)-C(251)-C(25) C(253)-C(251)-C(25) C(313)-C(311)-C(312) C(313)-C(311)-C(31) C(312)-C(311)-C(31) C(35)-C(351)-C(352) 120.0 127.9(8) 111.9(8) 120.0 119.2(5) 120.7 (5) 120.0 117.5(10) 122.5(10) 120.0 120.0 120.0 120.0 122.5(10) 117.5 (10) 120.0 119.0(9) 121.0(9) 120.0 116.6(11) 123.3(11) 120.0 120.0 120.0 120.0 120.0(10) 120.0(10) 120.0 122.0(9) 118.0(9) 120.0 120.0 120.0 120 .0 120.0 120.0 120.0(10) 120.0(10) 120 .0 120.0 120.0 120.0 120.0 120.0 121.5(11) 118.5(11) 111.9(14) 113(2) 111.5(14) 111(2) 113.0(14) 115(2) 109(2) 109(2) 116(2) 113(2) 109(2) 114.3(14) 110.8(14) 112.3 (14) 368 C(35)-C(351)-C(353) 110.3(14 C(352)-C(351)-C(353) 109.0(14) C(91)-C(92)-C(93) 121(5) C(92)-C(91)-C(91)#l 132(10Symmetry transformations used to generate equivalent atoms: #1 -x-l,-y+2,-z-l 369 Table 4. Anisotropic displacement parameters (A"2 x 10"3) for 1. The anisotropic displacement factor exponent takes the form: -2 piA2 [ h*2 a**2 Ull + ... + 2 h k a* b* U12 ] Ull U22 U33 U23 U13 U12 Ta C(l) N(l) C(2) N(2) C(3) C(4) C(5) C(6) C(7) C(8) C(ll) C(12) C(13) C(14) C(15) N(16) C(21) C(22) C{23) C(24) C(25) C(26) C(31) C(32) C(33) C(34) C(35) C(36) C(41) C(42) C(43) C(44) C(45) C(46) C(51) C(52) C(53) C(54) C(55) C(56) C{61) C(62) C<63) C(64) C(65) C(66) C(211) C(212) C(213) 44 (1) 74(10) 35(7) 49(8) 39(7) 32(8) 64(11) 65(11) 45(9) 64(11) 52(10) 37(9) 71(12) 51 (10) 73(12) 43 (9) 47 (7) 68 (11) 85(14) 76 (14) 95(15) 72(12) 45(10) 55 (9) 73 (12) 69(12) 77(12) 59 (10) 54(9) 54(10) 64(12) 70(12) 82(14) 62(11) 49 (9) 44 (11) 85(19) 54(14) 75(16) 66(13) 50(11) 78(13) 69(12) 71(15) 91(12) 82(13) 189(23) 110(15) 184(22) 125(17) 51(1) 46(8) 57(7) 56(9) 64(8) 83(11) 67(11) 67(11) 80(11) 81(12) 78(11) 63(10) 73(11) 90(13) 63(11) 53 (9) 63 (8) 60(11) 97(15) 120(19) 90(14) 55(11) 59 (10) 85(12) 106 (14) 134(18) 54(10) 36(9) 66(11) 96(13) 123(17) 125(17) 91(15) 89(14) 66 (10) 161(20) 164(25) 184(27) 189(25) 155(19) 111(14) 91(13) 165(21) 263(33) 68 (12) 79 (14) 112(18) 84(13) 169(21) 116 (16) 53(1) 40(8) 83(9) 31(8) 41(6) 61(10) 73(11) 69(10) 68(11) 96(13) 74(11) 98(12) 99(13) 107 (15) 86(12) 88(11) 53 (7) 83 (13) 93(14) 178(25) 158(21) 120(16) 78(12) 39(9) 52(10) 59(12) 79(12) 71 (10) 43(9) 49 (9) 84(13) 108(15) 122 (16) 103(14) 47(8) 171(21) 292(37) 218(30) 118(17) 98(14) 70 (11) 80(12) 102 (15) 215(28) 83(12) 152(19) 162(22) 78(13) 71(13) 141(19) -4(1) -1(7) -10(6) 1(7) 12(5) -4(8) 18(8) 5(8) -5(9) -19(10) -11(9) -9(9) -12 (10) 8(11) -12(9) 13 (9) -6(6) -39(10) -32(12) -62 (18) -45 (15) -41 (11) -17(9) -16(8) 19(10) -19(11) -15(9) -12(8) -7(8) -2(9) 4(11) 24 (13) -5(12) 14(10) 15(8) -15(16) 17(24) 84(23) 35(16) -12(13) 28(10) 2(10) -17(15) 19(24) 11(9) 38(13) 74(16) -44(11) 8(14) -23(14) 2(1) 7(7) 2(6) -12(7) -4(5) 9(8) 3(9) 24(9) 19 (8) -4(9) -8(8) 8(9) 5 (10) -2(10) 6(10) -2 (8) 7(6) 5(10) -18 (11) 12(15) 40(14) 22(11) 4 (9) 12 (7) 7(9) -6(9) -16(9) 8(8) -7(8) 2(8) 20 (10) 32(11) 21(12) 20(10) 1(7) 39(12) 81(21) 14(16) -18(13) 5(10) 20(9) 12(10) 0(10) -20 (16) 15(10) 11(12) 0(18) 7(11) 19(14) 33(14) 0(1) -3 (8) -5(6) 10(7) 10(6) 0(8) 5(8) -1(8) 4(8) 0(10) 1(8) 17 (8) 14(10) 7 (10) -3 (9) 5 (8) -8(6) -2(9) -2(11) -9(13) -28(12) -26(9) 17(8) 7(8) -15(11) -2(12) 27 (9) 1(7) 2(8) -1(9) 1(11) 3 (13) -27(11) 2(10) 0(9) -18(12) 4(16) 13(16) -40(16) -37(13) 5(10) 4(10) -2(14) -41(18) -3(9) -4(10) 11(16) 13(11) 55(18) 16(14) 370 C(251) 132 (18) 94(14) 125 (18) -29(13) 73(16) -42(13) C(252) 123 (21) 457(56) 128(22) 37(29) 16(17) 111 (30) C(253) 184 (23) 109 (17) 243(29) 65(19) 124(22) 24(17) C(3H) 113(15) 57(11) 105(14) 7(9) 38 (12) -19(10) C(312) 156(23) 152(22) 287(37) 118(24) -111(24) -59 (18) C(313) 144(18) 114(16) 102(15) 44(12) -17(13) -55(14) C(351) 101 (13) 28(9) 97(13) -8(8) 4(11) -5(9) C(352) 153(19) 109(16) 123(18) 32(13) 43(15) 19(14) C(353) 165(21) 125(18) 177(23) -23 (17) 63(18) -46(17) C(93) 317(67) 527(90) 250 (52) 103(55) 107(45) 255(62) C(92) 149(37) 501(108) 376(81) 13(80) 3 (44) 106(55) C(91) 300 (57) 300(82) 505(80) -247(90) 166(58) -78(73) 371 15 Design of polymerization reactoi 1000 mL LC SERIES STIRRED REACTOR WITH INTERNAL COMPONENTS DISPLAYED RATED FOR 138 BAR AT 350 C IN STAINLESS STEEL 373 CP-F-14 CONTROL PACKAGE PID TEMPERATURE CONTROL WITH DIGITAL TACHOMETER, DIGITAL PRESSURE INDICATION, AND HIGH SKIN TEMPERATURE SHUTDOWN 

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