{"http:\/\/dx.doi.org\/10.14288\/1.0059512":{"http:\/\/vivoweb.org\/ontology\/core#departmentOrSchool":[{"value":"Science, Faculty of","type":"literal","lang":"en"},{"value":"Chemistry, Department of","type":"literal","lang":"en"}],"http:\/\/www.europeana.eu\/schemas\/edm\/dataProvider":[{"value":"DSpace","type":"literal","lang":"en"}],"https:\/\/open.library.ubc.ca\/terms#degreeCampus":[{"value":"UBCV","type":"literal","lang":"en"}],"http:\/\/purl.org\/dc\/terms\/creator":[{"value":"Alexander, Christopher Scott","type":"literal","lang":"en"}],"http:\/\/purl.org\/dc\/terms\/issued":[{"value":"2009-04-15T21:38:34Z","type":"literal","lang":"en"},{"value":"1995","type":"literal","lang":"en"}],"http:\/\/vivoweb.org\/ontology\/core#relatedDegree":[{"value":"Doctor of Philosophy - PhD","type":"literal","lang":"en"}],"https:\/\/open.library.ubc.ca\/terms#degreeGrantor":[{"value":"University of British Columbia","type":"literal","lang":"en"}],"http:\/\/purl.org\/dc\/terms\/description":[{"value":"Treatment of RuII(porp)L\u2082 complexes with HX acids in C\u2086H\u2086 yields the corresponding\r\nparamagnetic RuIV(porp)X\u2082complexes, where porp = the 2, 3, 7, 8, 12, 13, 17, 18-\r\noctaethylporphyrin dianion(OEP), L= pyridine(py), X= Cl; and porp = the 5, 10, 15, 20-\r\ntetramesitylporphynn dianion(TMP), L =CH\u2083CN, X= Cl or Br. The 3 day reactions ( at room\r\ntemperature) proceed via the paramagnetic Ru III(porp)X(L) intermediates, as demonstrated by\r\nisolation of Ru III(OEP)Cl(py) and Ru III(TMP)Br(CH\u2083CN). The Ru(OEP)Cl(py) complex was\r\nalso produced in situ by the reaction of Ru(OEP)Cl\u2082 with Ru(OEP)py\u2082.Reduction of the\r\ndihalo species with anhydrous ammonia yields the paramagnetic Ru III(porp)X(NH\u2083)species.\r\nCyclic voltammograms of the Ru(porp)X\u2082 complexes (where porp = OEP, X = Cl; porp\r\n= TPP (TPP 5, 10, 15, 20-tetraphenylporphyrin dianion), X = Cl; porp = TMP, X Br and\r\nCl) show reversible Ru IV(porp\u207a) \/Ru IV(porp) couples in the range of 1.22 to 1.35 V, reversible\r\nRu(IV)fRu(III) couples from 0.41 to 0.64 V, and a third irreversible response (tentatively\r\nassigned to the Ru III(porp)\/Ru III(porp) couples) in the range of -0.82 to -0.56 V vs. Ag\/AgCI.\r\nThe reversible Ru IV(porp\u207a)\/Ru IV(porp) couples of Ru(OEP)Cl(NH\u2083)and\r\nRu(TMP)Cl(NH\u2083)were measured at 1.31 and 1.45 V vs. AgIAgC1, respectively, while the\r\nreversible Ru(IV)\/Ru(III) couples were found at 0.74 and 0.85 V. Reversible signals\r\n(tentatively assigned as the Ru(III)\/Ru(ll) couples) were also observed at -0.51 and -0.42 V\r\nvs. AgIAgC1 for the OEP and TIVIP complexes, respectively.\r\nThe diamagnetic Ru(TMP)R\u2082 complexes (R = Me, Ph) were isolated from the reaction\r\nof Ru(TMP)X\u2082 (X = Br, Cl) with an excess (\u22486 equivalents) of the corresponding RLi\r\nreagents. On the other hand, the products of the reactions of Ru(OEP)Cl\u2082 with the alkylating\r\nagents RnM [where n 1, R = neopentyl (Np), M = Li; n = 1, R = benzyl (Bz), M = K; n = 2,\r\nR = 2-methyl-2-phenylpropyl (neophyl), M = Mg] and reactions of Ru(TMP)X\u2082 (X = Cl, Br)\r\nwith NpLi were dependent on the ratios of the starting material. In situ experiments reveal the\r\nimportance of the reducing power of these alkylating agents, as complexes of oxidation states\r\nll-IV were observed, with the yield of the Ru(ll) products increasing as the ratio of\r\nNpLi\/Ru(OEP)Cl\u2082 increased. The paramagnetic Ru(OEP)Np and Ru(OEP)(neophyl), and the\r\ndiamagnetic, lithium-bridged dimer [Ru(OEP)Np]\u2082(\u03bc-Li)\u2082,were isolated from these reactions\r\nand unambiguously characterized by microanalysis, UV\/visible and \u00b9H NMR spectroscopies,\r\nand X-ray crystal diffraction. The Ru(OEP)Np species is also produced along with\r\nRu(OEP)(NH\u2083)\u2082 from the reaction of Ru(OEP)Cl(NH\u2083)with 1 equivalent of NpLi.\r\nThe paramagnetic nature of the new Ru(TMP)Cl\u2082,Ru(OEP)Cl(py), Ru(TMP)Cl(NH\u2083),\r\nRu(TMP)Br(NH 3)and Ru(OEP)Np and Ru(OEP)(neophyl) species is evidenced by their\r\nbroad, temperature-dependent \u00b9H NMR spectra and the solution magnetic susceptibilities of\r\nRu(TIVIP)Cl\u2082 (2.5 B.M.), Ru(TMP)Cl(NH\u2083) (1.61 B.M.), Ru(OEP)Np (2.4 B.M.) and\r\nRu(OEP)(neophyl) (2.2 B.M.).\r\nThe lithium-bridged species is of a unique type among metalloporphyrin complexes, and\r\nthe structure is maintained in solution; however, oxidation by air or byH\u2082O gave\r\n[Ru(OEP)OH]\u2082(\u03bc-O)and Ru(OEP)Np, respectively.\r\nThe Ru(TMP)R\u2082 species (R = Me, Ph) react with CO at 1 atm under laboratory light to\r\nyield Ru(TMP)(CO)\u2082 via the corresponding Ru(TMP)(COR)R intermediate. The conversion\r\nof Ru(TMP)(COPh)Ph is light-dependent and thus this benzyol species was produced in\r\nalmost quantitative yield by performing the reaction in the dark, and was identified by\r\nmicroanalysis, IR and \u00b9H NMR spectroscopy. The Ru(TMP)Me\u2082 species also undergoes a\r\nphoto-reaction with dioxygen to produce Ru(TMP)CO(L), where L is tentatively assigned as\r\nMeOH.\r\nThe Ru(TMP)R\u2082 complexes (R = Ph, Me) undergo thermal decomposition under\r\nanaerobic conditions to yield the corresponding five-coordinate, paramagnetic Ru(TMP)R\r\nspecies, as does Ru(OEP)(COPh)Ph to give Ru(TMP)Ph. The in situ Ru(OEP)Np\u2082 complex\r\nthermally decomposes to give a 50:50 mixture of Ru(OEP)Np and Ru(OEP)=CHC(CH\u2083)\u2083.All\r\nthese reactions proceed by the rate-determining homolysis of the axial metal-carbon bond, and\r\nEyring plots of the first-order rate constants (k\u2081) obtained at various temperatures yield\r\nactivation parameters for cleavage of the various Ru-R bonds [Ru(TMP)Ph\u2082,\u0394S\u2081\u2195, 33 kcal\r\nmol\u207b\u00b9 , \u0394S\u2081\u2195= 6.9 e.u. ; Ru(TMP)(COPh)Ph, \u0394H\u2081\u2195 = 22, \u0394S\u2081\u2195 = -11; Ru(TMP)Me\u2082, \u0394H\u2081\u2195 = 22,\r\n\u0394S\u2081\u2195= -17; Ru(OEP)Np\u2082, \u0394H\u2081\u2195 = 16, \u0394S\u2081\u2195 = -27]. The bond dissociation energies (BDE) of\r\nthese bonds are then estimated by an established method (i.e. BDE = \u0394H\u2081\u2195-2 kcal mol\u207b\u00b9), and\r\nthe accuracy of these estimates is discussed in light of the kinetic results.","type":"literal","lang":"en"}],"http:\/\/www.europeana.eu\/schemas\/edm\/aggregatedCHO":[{"value":"https:\/\/circle.library.ubc.ca\/rest\/handle\/2429\/7174?expand=metadata","type":"literal","lang":"en"}],"http:\/\/purl.org\/dc\/terms\/extent":[{"value":"5684289 bytes","type":"literal","lang":"en"}],"http:\/\/purl.org\/dc\/elements\/1.1\/format":[{"value":"application\/pdf","type":"literal","lang":"en"}],"http:\/\/www.w3.org\/2009\/08\/skos-reference\/skos.html#note":[{"value":"THE COORDINATION AND ORGANOMETALLICCHEMISTRY OF RUTHENIUM PORPHYRIN SPECIESByCHRISTOPHER SCOTT ALEXANDERB.Sc., The University of Guelph, 1984M.Sc., The University of Guelph, 1986A THESIS SUBMITTED TN PARTIAL FULFILMENT OFTHE REQUIREMENTS FOR THE DEGREE OFDOCTOR OF PHILOSOPHYinTHE FACULTY OF GRADUATE STUDIES(Department of Chemistry)We accept this thesis as conformingto the required standardTHE UNIVERSITY OF BRITISH COLUMBIAAugust 1995\u00a9 Christopher Scott Alexander, 1995In presenting this thesis in partial fulfilment of the requirements for an advanceddegree at the University of British Columbia, I agree that the Library shall make itfreely available for reference and study. I further agree that permission for extensivecopying of this thesis for scholarly purposes may be granted by the head of mydepartment or by his or her representatives. It is understood that copying orpublication of this thesis for financial gain shall not be allowed without my writtenpermission.(Signature)________________________________Department of L4The University of British ColumbiaVancouver, CanadaDate O_fDE-6 (2188)AbstractTreatment ofRu11(porp)L2complexes with FIX acids in C6H yields the correspondingparamagnetic Ru\u201dQorp)X2complexes, where porp = the 2, 3, 7, 8, 12, 13, 17, 18-octaethylporphyrin dianion(OEP), L= pyridine(py), X Cl; and porp = the 5, 10, 15, 20-tetramesitylporphynn dianion(TMP), L = CH3N, X= Cl or Br. The 3 day reactions ( at roomtemperature) proceed via the paramagnetic Ru(porp)X(L) intermediates, as demonstrated byisolation of Ru(OEP)Cl(py) and Ru(TMP)Br(CH3CN). The Ru(OEP)Cl(py) complex wasalso produced in situ by the reaction of Ru(OEP)C12with Ru(OEP)py2.Reduction of thedihalo species with anhydrous ammonia yields the paramagnetic Ru(porp)X(NH3species.Cyclic voltammograms of the Ru(porp)X2complexes (where porp = OEP, X = Cl; porp= TPP (TPP 5, 10, 15, 20-tetraphenylporphyrin dianion), X = Cl; porp = TMP, X Br andCl) show reversible Ru\u201d(porp) \/RuT(porp) couples in the range of 1.22 to 1.35 V, reversibleRu(IV)fRu(ffl) couples from 0.41 to 0.64 V, and a third irreversible response (tentativelyassigned to the Ru(jorp)\/Ru(porp) couples) in the range of -0. 82 to -0.56 V vs. Ag\/AgCI.The reversible Ru\u201d(porp)\/Ru\u201d(porp) couples of Ru(OEP)Cl(NH3)andRu(TMP)Cl(N113)were measured at 1.31 and 1.45 V vs. AgIAgC1, respectively, while thereversible Ru(IV)\/Ru(ffl) couples were found at 0.74 and 0.85 V. Reversible signals(tentatively assigned as the Ru(ffl)\/Ru(ll) couples) were also observed at -0.51 and -0.42 Vvs. AgIAgC1 for the OEP and TIVIP complexes, respectively.The diamagnetic Ru(TMP)R2complexes (R = Me, Ph) were isolated from the reaction\u2018aof Ru(TMP)X2(X = Br, Cl) with an excess ( 6 equivalents) of the corresponding RLireagents. On the other hand, the products of the reactions of Ru(OEP)C12with the alkylatingagents RM [where n 1, R = neopentyl (Np), M = Li; n = 1, R = benzyl (Bz), M = K; n = 2,R = 2-methyl-2-phenylpropyl (neophyl), M = Mg] and reactions of Ru(TMP)X2(X = Cl, Br)with NpLi were dependent on the ratios of the starting material. In situ experiments reveal theimportance of the reducing power of these alkylating agents, as complexes of oxidation statesll-IV were observed, with the yield of the Ru(ll) products increasing as the ratio ofNpLiIRu(OEP)Cl2increased. The paramagnetic Ru(OEP)Np and Ru(OEP)(neophyl), and thediamagnetic, lithium-bridged dimer [Ru(OEP)Np]2Q.-Li),were isolated from these reactionsand unambiguously characterized by microanalysis, UV\/visible and \u2018H NIvER spectroscopies,and X-ray crystal diffraction. The Ru(OEP)Np species is also produced along withRu(OEP)(NH3)2from the reaction of Ru(OEP)Cl(NH3)with 1 equivalent of NpLi.The paramagnetic nature of the new Ru(TMP)C12,Ru(OEP)Cl(py), Ru(TMP)Cl(NH3,Ru(TMP)Br(NH3)and Ru(OEP)Np and Ru(OEP)(neophyl) species is evidenced by theirbroad, temperature-dependent \u2018H NIVIR spectra and the solution magnetic susceptibilities ofRu(TIVIP)C12(2.5 B.M.), Ru(TMP)Cl(NH3(1.61 B.M.), Ru(OEP)Np (2.4 B.M.) andRu(OEP)(neophyl) (2.2 B.M.).The lithium-bridged species is of a unique type among metalloporphyrin complexes, andthe structure is maintained in solution; however, oxidation by air or by H20 gave[Ru(OEP)OH]2(i-O)and Ru(OEP)Np, respectively.The Ru(TMP)R2species (R = Me, Ph) react with CO at 1 atm under laboratory light toyield Ru(TMP)(CO)2via the corresponding Ru(TMP)(COR)R intermediate. The conversionII\u2019of Ru(TMP)(COPh)Ph is light-dependent and thus this benzyol species was produced inalmost quantitative yield by performing the reaction in the dark, and was identified bymicroanalysis, IR and \u2018H NIv[R spectroscopy. The Ru(TMP)Me2species also undergoes aphoto-reaction with dioxygen to produce Ru(TMP)CO(L), where L is tentatively assigned asMeOH.The Ru(TMP)R2complexes (R = Ph, Me) undergo thermal decomposition underanaerobic conditions to yield the corresponding five-coordinate, paramagnetic Ru(TMP)Rspecies, as does Ru(OEP)(COPh)Ph to give Ru(TMP)Ph. The in situ Ru(OEP)Np2complexthermally decomposes to give a 50:50 mixture of Ru(OEP)Np and Ru(OEP)=CHC(CH3).Allthese reactions proceed by the rate-determining homolysis of the axial metal-carbon bond, andEyring plots of the first-order rate constants (k1) obtained at various temperatures yieldactivation parameters for cleavage of the various Ru-R bonds [Ru(TMP)Ph2,zSH, 33 kcalmof\u2019 , AS,= 6.9 e.u. ; Ru(TMP)(COPh)Ph, AH, = 22, AS, = -11; Ru(TMP)Me2,AH1 = 22,-17; Ru(OEP)Np2,IJ1, = 16, AS, = -27], The bond dissociation energies (BDE) ofthese bonds are then estimated by an established method (i.e. BDE = AH,- 2 kcal mof\u2019), andthe accuracy of these estimates is discussed in light of the kinetic results.lvTable of ContentsABSTRACT.iiLIST OF FIGURES xLIST OF TABLES xivNUMBERING SCHEME FOR PORPHYRINS xviLIST OF ABBREVIATIONS xviiACKNOWLEDGMENTS xxiiDEDICATION xxiii1. INTRODUCTION TO RUTHENIUM PORPHYRIN CHEMISTRY I1.1 RUTHENIUM(II) DERIVATIVES 41.1.1 Synthesis and physical properties 41.1.2 Reactivity of Ru(porp)CO complexes 61.1.3 Reactivity of Ru(porp)L2complexes 101.1.4 Reactivity of [Ru(porp)12and Ru(TMP) 161.2 RUTHENTUM(0) Mfl) RUTHENTUM(I) DERIVATIVES 211.3 RUTHENTUM(III) DERIVATIVES 231.3.1 Synthesis and physical properties 231.3.2 Reactivity 251.4 RUTHENIUM(IV) DERIVATIVES 261.4.1 Synthesis and physical properties 261.4.2 Reactivity of Ru(IV) complexes 321.5 RUTHENTUM(VI) DERIVATIVES 341.6 CATALYTIC REACTIVITIES OF RUTIIENTUM PORPHYRiNCOMPLEXES 36V1.6.1 Decarbonylation. 361.6.2 Oxygenation\/oxidation 381.6.3 Hydrogenase models 391.7 SCOPE OF THIS THESIS 401.8 REFERENCES FOR CHAPTER 1 422. GENERAL EXPERIMENTAL PROCEDURES 502.1 MATERIALS 502.1.1 Solvents 502.1.2 Gases 502.1.3 Reagents 512.1.4 Ruthenium precursor complexes 512.1.5 Preparation of dichloro(octaethylporphyrinato)ruthenium(IV) 522.1.6 Preparation of tetramesitylporphyrin 532.1.7 Preparation of bis(2-methyl-2-phenyl-propyl)magnesium(II) 542.1.8 Preparation of neopentyllithium (I) 552.1.9 Preparation of Na(naphthalenide) 552.2 METHODS 562.2.1 Instrumentation 562.2.2 Cyclic voltammetry 562.2.3 Special techniques 592.2.4 Anaerobic columns 602.3 PREPARATION OF NEW RUTHENIUM PORPHYRIN COMPLEXES 612.3.1 Preparation of (neopentyl)(octaethylporphyrinato)ruthenium(III) 612.3.2 Preparation of neophyl(octaethylporphyrinato)ruthenium(III) 622.3.3 Preparation of [Ru(OEP)Np12(p.-Li) 632.3.4 Preparation of lrans-dichloro(tetramesitylporphyrinato)ruthenium(IV) 642.3.5 Preparation of ammine(chloro)(tetramesitylporphyrinato)ruthenium(Ill).... 652.3.6 Preparation of bisphenyl(tetramesitylporphyrinato)ruthenium(IV) 65vi2.3.7 Preparation of benzoyl(phenyl)(tetramesitylporphyrinato)ruthenium(IV).... 662.3.8 Preparation of dimethyl(tetramesitylporphyrinato)ruthenium(IV) 672.3.9 Kinetics of the decomposition of Ru(TMP)Ph2 682.3.10 Kinetics of the decomposition of Ru(TMP)(COPh)Ph andRu(TMP)(Me) 682.3.11 Kinetics of the decomposition of Ru(OEP)Np2 692.4 REFERENCES FOR CHAPTER 2 703. HALO(PORPHYRINATO)RUTHENIUM DERIVATIVES 713.1 Ru(IV)(PORP)X2DERIVATIVES (PORP = OEP AND TMP) 713.1.1 Preparation of Ru(OEP)X2derivatives 723.1.2 Preparation and characterization of Ru(TMP)C12 753.1.3 Electrochemistry of Ru(porp)X2complexes 833.2 Ru(PORP)X(L) DERIVATIVES (L = NH3, Py, X = HALOGEN) 893.2.1 Preparation of Ru(porp)X(NH3complexes (porp = OEP, X= Cl; porp =TMP,X=ClandBr) 913.2.2 Characterization ofRu(TMP)Cl(NH3and Ru(TMP)Br(NH3) 923.2.3 Preparation and characterization of Ru(OEP)Cl(py) 973.2.4 Attempts to prepare Ru(OEP)Cl 1013.2.5 Electrochemistry of the Ru(III) derivatives 1073.3 THE OXIDATION OF Ru(II) COMPLEXES REVISITED 1103.4 REFERENCES FOR CHAPTER 3 1164. ALKYL COMPLEXES OF RUTHENIUM OCTAETHYLPORPHYRIN 1204.1 REACTION OF Ru(OEP)X2WITH NEOPENTYL LITHIUM 1224.1.1 Reaction with two equivalents of neopentyllithium 1234.1.2 Thermal decomposition of Ru(OEP)Np2 1284.1.3 Reaction with three equivalents of neopentyllithium 1354.1.4 Reaction with 4 equivalents of neopentyllithium 1404.2 REACTION OF Ru(OEP)Cl(NH3)WITH NEOPENTYLLITITILJM 143vu4.3 REACTION OF Ru(OEP)Cl2WITH (NEOPHYL)2Mg.1484.4 REACTION OF Ru(OEP)C12WITH BENZYLPOTASSIUM 1494.5 CHARACTERIZATION OF ISOLATED COMPLEXES 1534.5.1 Preparation and isolation ofRu(OEP)CHC(CH3),Ru(OEP)Np andRu(OEP)(neophyl) 1534.5.2 Spectral characteristics 1554.5.3 Crystal structures of Ru(OEP)Np and Ru(OEP)(neophyl) 1624.5.4 Preparation and characterization of [Ru(OEP)Np]2(p.-Li) 1664.5.5 Crystal Structure of[Ru(OEP)NpJ2(.t-Li) 1684.6 REACTIVITY OF [Ru(OEP)Np]Q.t-Li) 1714.6.1 Reaction with 02 1714.6.2 Reaction with H20 1744.6.3 Reaction with NH3 1764.7 REFERENCES FOR CHAPTER 4 1805. ORGANOMETALLIC COMPLEXES OF (TETRAMESITYLPORPHYRINATO)RUTHENIUM 1835.1 INTRODUCTION 1835.2 PREPARATION AND CHARACTERIZATION OF Ru(TMP)R2COMPLEXES 1845.3 REACTION OF Ru(TMP)X2(X= Cl or Br) WITH NpLi 1905.4 REACTION OF Ru(TMP)R2(R= Me, Ph) COMPLEXES WITH CO 2015.5 KINETICS OF THE DECOMPOSITION OF THE Ru(TMP)R2COMPLEXES 2095.5.1 Thermal decomposition of Ru(TIvIP)Ph2 2145.5.2 Thermal decomposition of Ru(TMP)(COPh)Ph 2175.5.3 Thermal decomposition ofRu(TMP)Me2 2205.5.4 Determination of the strength of Ru-R bonds (R= Ph, PhCO and Me) 2235.6 PHOTOREACTIONS OF Ru(TMP)Me2 2265.7 REFERENCES FOR CHAPTER 5 234VIII6. GENERAL CONCLUSIONS AND RECOMMENDATIONS FOR FUTUREWORK 238APPENDIX A: TEMPERATURE DEPENDENCE\u2019S OF THE ISOTROPICPROTON SHIFTS 243APPENDIX B: KINETIC DATA FOR THE ANAEROBIC THERMOLYSIS OFRu(PORP)R2COMPLEXES 254APPENDIX C: X-RAY CRYSTALLOGRAPIC ANALYSIS OF Ru(OEP)Np ...248APPENDIX D: X-RAY CRYSTALLOGRAPHIC ANALYSIS OFRu(OEP)(NEOPHYL) 256APPENDIX E: X-RAY CRYSTALLOGRAPHIC ANALYSIS OF[Ru(OEP)Np12(i.t-Li) 265APPENDIX F: X-RAY CRYSTALLOGRAPHIC ANALYSIS OFRu(TMP)Ph2 274lxList of FiguresFigure 1-1: The structures of, a) porphine dianion, b) heme, c) free-base porphyrins usedin the work 2Figure 1-2: Molecular orbital diagram for [Ru(OEP)]2 15Figure 1-3: Structure of Ru2DPB (DPB = diporphyrinatobiphenylene tetraanion) 17Figure 1-4: The possible ground state configurations for the three lowest levels of a d4metal in a tetragonally distorted octahedral crystal field 32Figure 2-1: Electrochemical cell used for cyclic voltammetry 57Figure 2-2: Anaerobic glassware; a) NIVIR tube, b)UV\/visible cell 59Figure 2-3 : Apparatus used for the chromatographic purification of air-sensitivecompounds 60Figure 3-1: UV\/visible spectrum ofRu(TMP)C12(10 .tM in CH21) 78Figure 3-2: \u2018H NMR spectrum (300 MHz) ofRu(TMP)C12in C6D at 200 C 79Figure 3-3: Plot of the isotropic chemical shift vs. lIT (K\u2019) for Ru(TMP)Cl2 81Figure 3-4: Cyclic voltammogram of Ru(TMP)C12 83Figure 3-5: Cyclic voltammograms of Ru(OEP)C12(0.5 mM) 88Figure 3-6: UVlvisible spectrum of Ru(TMP)Cl(NH3) 92Figure 3-7: \u2018H NMR spectrum (300 MHz) of Ru(TMP)Cl(NH3in C6D taken at293 K 94Figure 3-8: \u2018H NMR spectrum (300MHz) of isolated Ru(TMP)Br(NH3)in C6D taken at293 K 95Figure 3-9: Plot of isotropic chemical shift vs. l\/T (K) for Ru(TMP)Cl(NH3 96Figure 3-10: \u2018H NIVIR spectrum (300 MHz) of Ru(OEP)Cl(py) in C6D taken at293 K 99Figure 3-11: \u2018H NMR spectrum (C6D,20 \u00b0C, 300 MHz) of the products of the reactionof Ru(OEP)C12with 1 equivalent of sodium naphthalenide 105Figure 3-12: Cyclic voltammogram of Ru(OEP)Cl(NH3) 108xFigure 4-1: \u201811 NMR (C6D)spectrum of the products of the reaction of Ru(OEP)C12with 2 equivalents ofNpLi 124Figure 4-2: First-order plot for the thermal decomposition of Ru(OEP)Np2at 38\u00b0 C... 129Figure 4-3: Eyring plot for the decomposition of Ru(OEP)Np2 132Figure 4-4: Reaction profile for the decomposition of Ru(OEP)Np2,showing therelationship between the bond dissociation energy (BDE) and the enthalpies ofactivation (t\\H) 133Figure 4-5: \u2018H NIvIR spectrum of the products of the reaction of Ru(OEP)C12with 3equivalents ofNpLi 136Figure 4-6: \u2018H NIv1R spectrum of the products of the reaction of Ru(OEP)C12 with 4equivalents ofNpLi 141Figure 4-7: Proposed structure for the co-product of the reaction of Ru(OEP)C12withfour equivalents ofNpLi 142Figure 4-8: \u2018H NMR spectrum (C6D)of the products of the reaction ofRu(OEP)C1(NH3)with one equivalent ofNpLi 144Figure 4-9: \u2018H NMR spectrum ofRu(OEP)(NH3)2produced in situ by the reaction of[Ru(OEP)12with anhydrous NH3 145Figure 4-10: \u2018H NMR spectrum of Ru(OEP)Np(NH)produced in situ by the reaction ofRu(OEP)Np with anhydrous NH3 147Figure 4-1 la: \u2018H NMR spectrum of the products of reaction of Ru(OEP)C12with 2equivalent of BzK after 30 mm 150Figure 4-12: \u2018H NIvIR spectrum (C6D,300 MHz) ofRu(OEP)CHC(CH3isolated fromthe reaction of Ru(OEP)C12with 2 equivalents ofNpLi 156Figure 4-13: \u2018H NMR spectrum (C6D,300 MHz) of Ru(OEP)Np (T=22\u00b0 C) 157Figure 4-14: \u2018H NMR spectrum (C6D,300 MHz) of Ru(OEP)(neophyl) (T50\u00b0 C)... 158Figure 4-15: Isotroic chemical shift vs. lIT for Ru(OEP)(neopentyl) in CDC13 161Figure 4-16: Isotropic chemical shift vs. lIT for Ru(OEP)(neophyl) ind8-toluene 161Figure 4-17: ORTEP diagram of Ru(OEP)Np; thermal ellipsiod 33% 163Figure 4-18: ORTEP diagram of Ru(OEP)(neophyl); thermal ellipsoids 33% 165Figure 4-19: \u2018H N1\\4R spectrum (C6D,300 MF{z) of [Ru(OEP)Np]2(.i-Li) 167xiFigure 4-20: ORTEP Diagram of[Ru(0EP)Np]2(.t-Li);thermal ellipsoids 33% 169Figure 4-21: 1H NIVIR spectrum (C6D,300 1VIHz) of the products of the reaction of[Ru(OEP)Np1(p.-Li)with 02. Spectra were collected: a) within 5 minutes; b)after 2 days 172Figure 4-22: \u2018H N1VIR (300 MHz) spectral changes observed over time for the reaction of[Ru(0EP)Np](.t-Li)( 3mM) in water-saturated ( 30 mM) C6D 175Figure 4-23: 1H NEVIR spectrum (C6D,300 MHz) of [Ru(OEP)Np]2(p.-Li) ( 7mM)under anhydrous NH3 177Figure 5-1: \u2018H N1VIR spectrum (C6D,300 MHz) ofRu(TMP)Ph2 186Figure 5-2: \u2018H NMR spectrum (C6D,300 Mz) ofRu(TMP)Me 187Figure 5-3: a) ORTEP diagram of Ru(TIVIP)Ph2.b) Proposed structure; thermalellipsoids 33% 188Figure 5-4: \u2018H NMR spectrum (C6D,300 IVIHz) of the products of the reaction ofRu(TMP)C12with 2 equivalents NpLi 192Figure 5-5: 1H N1VIR spectrum (C6D,300 MHz) of the products of the reaction ofRu(TMP)Cl2with 3 equivalents ofNpLi 194Figure 5-6: \u2018H NMR spectrum (C6D,300 MHz) of the products of the reaction ofRu(TMP)Br2with 7 equivalents of neopentyl lithium 197Figure 5-7: a) \u2018H N[VIR spectrum (C6D,300 IVIHz) of Ru(TMP)(COPh)Ph 204Figure 5-8: 1 N\u2019R spectrum (C6D,300 MHz) ofRu(TMP)Me2under C0(1 atm) for 5days 206Figure 5-9: 1H NIVIR spectrum (d8- toluene, 300 MHz) of Ru(TIVIP)Me prepared via theanaerobic thermolysis ofRu(TMP)Me2at 1110 C for 24 h 211Figure 5-10: \u2018H NMR spectrum (d8- toluene, 300 MHz) of Ru(TMP)Ph prepared via theanaerobic thermolysis ofRu(TMP)Ph2at 1110 C for 24 h 212Figure 5-11: UV\/visible absorbance changes (measured at 25\u00b0 C) for the thermolysis ofRu(TMP)Ph2at 111\u00b0 C 214Figure 5-12: First-order plot for the thermal decomposition of Ru(TMP)Ph2in toluene at111\u00b0C 215xl\u2019Figure 5-13: Eyring plot for the decomposition of Ru(TMP)Ph2 217Figure 5-14: First-order plot for the thermal decomposition of Ru(TMP)(COPh)(Ph) indg-toluene at 800 C 218Figure 5-15: Eyring plot for the decomposition of Ru(TMP)(COPh)Ph 219Figure 5-16: First-order plot for the thermal decomposition of Ru(T1VIP)Me2in toluene at70\u00b0C 220Figure 5-17:Eyring plot for the decomposition of Ru(TMP)Me2 224Figure 5-18: \u2018H NMR spectrum(d8-toluene, 300 mHz) of Ru(TMP)CO(MeOH)produced by the photolysis of Ru(TMP)Me2under 1 atm 02 228Figure C-i: PLUTO Plot showing the numbering scheme of Ru(OEP)Np 248Figure C-2: Stereoview of Ru(OEP)Np 249Figure D-1: PLUTO Plot showing the numbering scheme for Ru(OEP)(neophyl) 256Figure D-2: Stereoview of Ru(OEP)(neophyl) 257Figure E- 1: ORTEP plot of a monomeric unit of [Ru(OEP)NpJ2(.t-Li) 265Figure E-2: Stereoview of[Ru(OEP)Np12(t-Li) 266Figure F-i: PLUTO Plot showing the numbering scheme of Ru(TMP)Ph2 274Figure F-2: Stereoview of Ru(TMP)Ph2 275XIIIList of TablesTable 3-1: Reduction potentials of Ru(IV)(porp)X2complexes (\u00b1 .01 V vs. Ag\/AgCl)... 84Table 3-2: Reduction potentials for Ru(ffl)(porp)X(L) complexes (\u00b1 0.01 V vs.Ag\/AgC1) 108Table 4-1: Rate constants for the decomposition of Ru(OEP)Np2at varioustemperatures 132Table 4-2: \u2018H NMR spectra of the discussed Ru(OEP) complexes 179Table 5-1: Selected dimensions for some ruthenium porphyrin complexes 189Table 5-2: \u2018H NIVIR (C6D,300 MHz) signals observed following the reaction ofRu(TMP)Cl2 with 2 equivalents of neopentyllithium 193Table 5-3: Observed rate constants for the decomposition ofRu(TMP)Ph2 at varioustemperatures in toluene 216Table 5-4: Observed rate constants for the thermolysis ofRu(TMP)(COPh)Phin toluene 219Table 5-5: Observed rate constants for the thermolysis ofRu(TMP)Me2ind8-toluene atvarious temperatures 223Table 5-6: Bond dissociation energies for the axial Ru-R bonds of some Ru(porp)R2complexes 225Table C-i: Experimental Details for the X-ray diffraction analysis of Ru(OEP)Np 250Table C-2: Atomic coordinates and Beq 252Table C-3: Bond Lengths (A) 253Table C-4: Bond Angles (0) 254Table C-5: Least Square Planes 255Table D-1: Experimental Details for the X-ray diffraction analysis ofRu(OEP)(neophyl) 258Table D-2: Atomic coordinates and Beq 260xivTable D-3: Bond Lengths(A).261Table D-4: Bond Angles (\u00b0) 262Table D-5: Least Square Planes 264Table E- 1: Experimental Details for the X-ray difiiaction analysis of[Ru(OEP)Np]2(p-Li) 267Table E-2: Atomic coordinates and Beq 269Table E-3: Bond Lengths (A) 270Table E-4: Bond Angles (\u00b0) 271Table E-5: Least Square Planes 273Table F-i: Experimental Details for the X-ray diffraction analysis ofRu(TMP)Ph2 276Table F-2: Atomic coordinates and Beq 278Table F-3: Bond Lengths (A) 279Table F-4: Bond Angles (\u00b0) 280Table F-5: Least Square Planes 281xvNumbering Scheme for Porphyrins.8 (pyrrole)20\\ \/ 1O(meso)19\u2014N Nz18\u2019 1217 15 13Note: Carbons 2, 3, 7, 8, 12, 13, 17 and 18 are referred to as the pyrrole positions andcarbons 5, 10, 15 and 20 are referred to as the meso positions.xv\u2019List of AbbreviationsA absorbanceA Angstrom unit (100 meter)Anal. calcd analysis calculatedatm atmosphereBDE bond dissociation energyB.M. Bohr magnetonbr broad, in NN\u2019IR spectroscopyBu normal butyltBu tert-butylBzK benzyl potassiumC degree Celsiuscarbon-13 isotopem-CPBA meta-chloroperbenzoic acidcm centimetercm\u2019 wave number, in JR spectroscopyCV cyclic voltammogramd day, deuterium or doublet, in NIVIR spectroscopyDMA N, N\u2019-dimethylacetamide (CH3CON(CH)2DMF N, N\u2019-dimethylformamide (HCON(CH3)2xviiDMSO dimethylsulfoxide ((CH3)2S0)DPB diporphyrinatobiphenylene tetraanione electronE potentialchange of potentialEl electron impact mode in mass spectroscopyeq. equationEt ethyle.u. cal mol\u2019 IC\u2019FT Fourier transformg gramGC gas chromatography\u2018H protonactivation enthalpyh hourhv light energyHz HertzIR infraredK equilibrium constant or degree Kelvink kinetic rate constantk0b observed kinetic rate constantkeal kilocaloriesmitL ligand7Li lithium-7 isotopeM metal or molaritym multiplet in NMR spectroscopym meta-proton on an aryl or pyridine ringm-CPBA meta-chloroperbenzoic acidMe methyl (CH3-)MeO methoxy (CH3O-)mg milligrammL millilitermmol millimolemol moleMS mass spectroscopymV millivoltsnaph naphthalenenm nanometerNp neopentylNp neopentyl radicalNpLi neopentyllithiumNMR nuclear magnetic resonanceo ortho-proton on an aryl or pyridine ringOCP 5, 10, 15, 20-tetra(2, 6-dichlorophenyl)porphyrinato dianionxixOEP 2, 3, 7, 8, 12, 13, 17, 18-octaethylporphyrinOFP 5, 10, 15, 20-tetra(2, 6-fluorophenyl)porphyrinato dianionp para-proton on an aryl or pyridine ringPh phenyl (C6H5-)Pfr phenyl radicalPhIO iodosobenzeneporp generic porphyrinato dianionppm or \u00f6 chemical shift in parts per million relative to TMSpy pyridinepyrr pyrrole positions on the porphyrinq quartet in N?v\u2019IR spectroscopyR alkyl or arylRLi organolithiumRMgX Grignard reagentRT room temperatureS spin states second or singlet in NMR spectroscopyLS activation entropyT temperatureT1 spin lattice relaxation timeTBAP tetra-n-butylammonium perchiorateTBHP tert-butyl hydroperoxidexxTEMPO tetramethyl- 1 -piperidinyloxyTHF tetrahydrofuranTMP 5, 10, 15, 20-tetramesitylporphyrinato dianionTMS tetramethylsilaneTPP 5, 10, 15, 20-tetraphenyporphyrinato dianionUV ultra-violetV voltsX halidev Infrared frequencywavelength of a principle absorption peak in UV\/vis spectroscopyJ.Leff effective magnetic moment.tL microliterc molar absorptivity (extinction coefficient)xx\u2019AcknowledgmentsFirst, I would like to thank my supervisor Professor Brian James, whose continuoussupport made this work possible. I would also like to thank all the members of the Jamesresearch group who have come and gone over the years. Special thanks go to Don Yapp,Ken MacFarlane, Grant Meng and Richard Schutte for lending an ear and helping mework through some of the more confusing aspects of this work. I would also like to thankProfessor Micheal Fryzuk and his group, for allowing liberal access to their glove box.Specifically I would like to thank Guy Clentsmith and Dave McConville, andMurugesipilai Mylvaganum for their help when I was working in their labs.I would like to thank all the members of the Department staff who provided serviceover the years. The number of people who helped is far to many to list here, however Iwould mention Dr. S. Rettig for the X-ray crystallography, Peter Borda for the elementalanalysis, Dr. N. Burlinson, Marietta Austria and Liane Darge for their help with NEVERspectroscopy and S. Rak for glass blowing.Finally, I would like to thank my wife Christine for her Job-like patience andsupport.xxiiFor Christinexxii\u2019Chapter 11. Introduction to Ruthenium Porphyrin ChemistryThe study of the chemistry of porphyrins and metalloporphyrins has been vigorouslypursued since chlorohemin was first crystallized in 18521 and progress in the field has beenwell documented.2 The impetus for this research stems from the interest in biologicallyimportant proteins such as oxygen carriers (hemoglobin), electron-transfer cytochromesand oxygen reducing enzymes (cytochrome P-450) as these species contain themetalloporphyrin unit heme3 at the active site of the molecule. Workers have alsoattempted to derive insight into other porphyrin-like systems such as chlorophyll4andvitamin B12.5 To this end, many porphyrin and metalloporphyrin model complexes havebeen prepared, and extensive research into the structure, physical properties and thereactivity of these species has been done. While this work has improved ourunderstanding of the functions of the naturally occurring systems, it has also providedinteresting and varied chemistry in itself.The porphine dianion, illustrated in Figure 1-1 a is the structural template for allporphyrin ligands. Typically, these tetradentate dianionic ligands bind via the 4 nitrogenatoms with the metal sitting approximately in the center of the macrocycle. This restrictsany subsequent ligand binding to the axial sites. This constraint has led to someinteresting chemistry involving strong trans effects and radical mechanisms (see chapters 4and 5). Metalloporphyrin complexes have extensive ic-systems involving the 11 double12-a) b)octaethylporphyrinA=H, B=CH2CH3tetraphenylporphyrinc) A A=, B=HtetramesitylporphyrinA=\u00d8-, B=HFigure 1-1: The structures of a) porphine dianion, b) heme, c) free-base porphyrinsused in the work.BBB A B2bonds illustrated in Figure 1-la, and this feature results in very distinctive electronicspectra which have often proven very useftil in the characterization of these complexes.Protoporphyrin IX is the porphyrin ligand found in naturally occurring systems. Theheme moiety, shown in Figure 1-ib, is composed of an iron(II) ion inserted into thecentral cavity of this porphyrin. This group in turn is found within large proteins andusually constitutes the active site of the system. To say the least, these are very complexsystems, and initial work in the field focused primarily on isolating the heme moiety inorder to study its reactivity in the absence of the protein. Alternatively, workconcentrated on preparing analogues of protoporphyrin IX and heme, and studying theproperties of these systems. By altering the functional groups around the periphery of theporphyrin, researchers have managed to create a multitude of derivatives with which towork. Figure 1-1 c illustrates the porphyrin ligands that were involved in the present work.Today, metalloporphyrin complexes representing almost the entire periodic table ofelements have been prepared, although iron complexes have been by far the mostextensively studied. Although a great deal has been learned from this work, many of theintermediate species described in the iron chemistry have been proposed by indirectevidence. This is due to the short lifetime of these species. In an attempt to overcomethis problem, researchers in this and other laboratories have undertaken the task ofpreparing and studying porphyrin complexes of ruthenium, which lies directly below ironin the periodic table. The hope was that these species would exhibit chemistry that was ofdirect relevance to the iron systems, yet would provide added stability so that analogues ofthe latent intermediates proposed in the iron work could be directly observed or isolated.3The first ruthenium porphyrin complex was described in 1969,6 although it was notcorrectly characterized as Ru(TPP)(CO)(EtOH) until two years later.7 Studies thatfocused primarily on Ru(II) complexes continued throughout the 1970s. However, agreat deal of progress has been made since that time and, as of today complexes inoxidation states of 0-VI (except for V) have been isolated or detected. Complexes withC-, N-, P-, As-, 0-, S-, and halogen-donor ligands have been prepared, including somepossibly biologically relevant species containing small diatomic gases such as 02, N2, andCO. The purpose of this chapter is to provide the reader with a brief summary of theprogress made in this field with the hopes of providing some perspective for materialdiscussed in subsequent chapters.1.1 Ruthenium(ll) Derivatives1.1.1 Synthesis and physica\u2019 propertiesComplexes of this oxidation state constitute the largest class of ruthenium porphyrinsystems and are inevitably the starting point for any work in this field. This is becausealmost every successful insertion of ruthenium into a free-base porphyrin has resulted inthe formation of a Ru(II)(porp)(carbonyl) complex.7\u20198These preparations involverefluxing solutions of ruthenium precursors such as Ru3(CO)12,RuC13(H20), or[RuCI2(CO)3}and a free base porphyrin under CO or N2 gas (eq. 1.1). The solvents usedare usually high boiling and non-coordinating such as toluene or mesitylene. In the4N orCORu3(CO)12 + H2porp 2 Ru(porp)(CO)L 11refluxfinal product, the coordination site trans to the carbonyl ligand can be vacant, but oftencontains a weakly coordinating sixth ligand (such as an alcohol) that is picked up duringthe final work-up. Attempts to metallate the porphyrins, using precursors such asRuC12(DMSO)4or Ru(DMSO)62,to give products without an axial carbonyl ligand wereunsuccessfhl.9 The only exception where metalation resulted in a product other than acarbonyl complex involved insertion ofRu3(CO)12 into the N, N-bridgedtetraphenylporphyrin to give the carbene complex shown in reaction 1.2.10 Mechanismsfor these reactions (eq. 1.1 and 1.2) have not been reported.R\u2022R RcJII IIC Ru3(CO)12THFR=p-CIC6H4 1.2At this time, numerous Ru(porp)CO complexes have been prepared including someof the more exotic systems such as the \u201cpicnic basket8e,hl or \u201cpicket porphyrincomplexes. Consequently, the 11, physical\u20192and electrochemical\u20193properties of these species have been well documented.All of the known carbonyl complexes exhibit remarkable chemical stability and forexample, can be easily handled under aerobic conditions. This stability has been attributedto the strong Ru to L back-bonding from the dir orbitals of the ruthenium to the empty 7r5orbitals of the carbonyl group. This interaction is well documented in organometallicchemistry and can be verified by a study of the vibrational spectra of these compounds.The net result of placing electrons in the ic orbitals is a subsequent weakening of the CObond. This is evident in the energy of the vco stretching frequencies which fall in therange of 1889-1969 considerably lower than the value of 2143 cm\u2019 for free CO.The frequency of this vibration is influenced by the basicity of the porphyrin and the donorproperties of the trans axial ligands.1.1.2 Reactivity of Ru(porp)CO complexesThe ruthenium carbonyl interaction described above causes this bond to be relativelyinert. Accordingly, initial studies of the reactivity of these complexes were limited to anexamination of the exchange of ligands at the sixth axial position. Several in situ studieshave been carried out to inspect these fast equilibrium reactions (eq 3.1).KRu(porp)CO + L q Ru(porp)(CO)L 1.3The magnitude of the equilibrium constant in these systems depends largely on theproperties of the ligand L. For example, studies have demonstrated that there is a directcorrelation between K and the donor number of the ligand L (L=CH3CN, THE andpyridine).\u20193 Further work, equilibrium constants in the range of 4.2 x iO to 4.3 x iOwere obtained for 20 different nitrogenous bases, and a trend of increasing withincreasing pKa of the ligand was observed. 13e Nitrogen donor ligands are of interest inattempts to understand interactions in proteins.6Neutral oxygen donors tend to bind relatively weakly, while ligands withphosphorus donors exhibit the highest stability presumably due to strong a-donationcoupled with some it-back donation into empty d orbitals of the phosphorus. Overall, thegeneral stability trend increases in the order 0< N