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Synthesis and characterization of some triosmium and triruthenium cluster complexes containing unusual… Zheng, Tu C. 1993

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SYNTHESES AND CHARACTERIZATION OF SOMETRIOSMIUM AND TRIRUTHENIUM CLUSTER COMPLEXESCONTAINING UNUSUAL FERROCENYL MOIETIESbyTU CAI ZHENGB.Sc., FUDAN UNIVERSITY, 1985Shanghai, the People's Republic of ChinaA THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THEREQUIREMENT FOR THE DEGREE OF DOCTOR OF PHILOSOPHYinTHE FACULTY OF GRADUATE STUDIESDepartment of ChemistryWe accept this thesis as conforming to the required standardThe University of British ColumbiaMarch, 1993© Tu Cai Zheng, 1993In 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 C 1-tEN■:LV(2\v-The University of British ColumbiaVancouver, CanadaDate^7G(Aksz_^1193 DE-6 (2/88)ABSTRACTSeries of ferrocenyl ligands, predominantly phosphines, have beenprepared: PFcPh2 (Fc=(r1 5 -05H4)Fe(n 5 -05H5)), PFc2Ph, PEt2Fc, PEtFc2, PFc iPrz,PnBuFcPh, PtBu2Fc, Fc'PPh (Fc'4n 5 -05H4)2Fe), Fc'(PPh2 )2, Fc'(PiPr2 )2pAsFc2Ph, FC(SPh)2, Fc .(SMe)2, SFcPh, Fc2S2, and SbFc3, and characterized byspectroscopic and analytical techniques.The reactions of most of the ferrocenylphosphine ligands withM3(CO)12 (M=Os, Ru) were studied and a series of complexes of generalformulae M3(C0)1 IL, M3(CO)1 01,2, Ru3(CO)9L3, M3(C0)10(L-L), Ru3(CO)9(L-L)L' were prepared and characterized by spectroscopic and analyticaltechniques. The disubstituted compounds M3(C0)10L2 were found to existas symmetrical and unsymmetrical isomers. The electronic effectsaccounting for this phenomenon are discussed. The structure of theunsymmetrical isomer of 0s3(C0)10(PFc2Ph)2 (I) was determined.Os (C0)4Os^Os —P Fc2PhFc2PhP/(C0)3^(CO)3(I )A large number of pyrolytic reactions of these complexes and/orpyrolytic reactions of M3(C0)12 (M=Os or Ru) with an appropriate ligandwere studied in order to prepare metal cluster complexes containingunusual ferrocenyl moieties.iiFe(C0)3OsH ' A08 4-1t 0)2P iPre'Pr2P/(C0)2)17 011\sOs `Os(C0)3Cis(C )3^Os^,Os(CO) (C0)3FcThese pyrolytic reactions mentioned above have afforded manyinteresting complexes containing two to five metal atoms with the mostcommon one being three metal atoms. Over a hundred complexes, many ofthem novel, have been prepared and characterized by spectroscopic andanalytical techniques. Over thirty of these have been structurallycharacterized by using X-ray crystallography, and over thirty awaitanalysis.The novel ferrocyne and ferrodicyne complexes (II) and (III) havebeen prepared via the pyrolysis of 0s3(C0)11(PFc2Ph) and 0s3(C0)10[Fe(PiPr2)2] respectively and structurally characterized. Four series ofcomplexes (IV), (V), (VI), and (VII) containing Fe (ferrocene)-M (Os or Ru)bonds have been characterized. Series (IV) and (V) show Fe-Os bonddistances from 2.813(1) to 2.858(1) A. Some other novel complexes includethe first cluster naphthyne complex (VIII), the first 11.3-71 1 ,11 1 ,11 6 bondedbenzyne complex (VIV), complex (X) resulting from a CO insertion into anOs-R bond, complex (XI) derived from Ph2S, complex (XII) obtained via i-iiip R 1 R2Os(C0)3V / HOs^Os(CO)H,(0)3(V)PFcPhICO(VII)Ru(CO)3P'Pr'Pr2(VI)(C0)>H CONOs N^os^FePr and Fc C-H oxidative addition reactions, and complex (XIII) containing a11-11 1 ,715 bonded C5H4 moiety that is derived from a ferrocenyl group.R 1 R2=FcPhR 1 R2. ipr2R 1 R2=EtFc(IV)14 R2 P h2Ri R2 = Et 2 R=Fc R=PhDetailed reaction sequences have been proposed for the pyrolyses ofM3(C0)10[Fe(PiPr2 )21 (M=Os, Ru), 0s3(C0)11(PFc2Ph), 0s3(C0)1 (PFciPr2), and0s3(C0)11(PEt2Fc). In addition to a common Fe-M bonding involvement,ferrocenyl groups have been found to undergo orthometalation, hetero-annular metalation, or both, and these reactions are more facile than alkylC-H bond activation of ethyl and i-propyl groups. Ethyl and n-butyl groupsiv(CO)N Z(C0)3Fc(XIII)Fc''PrPI CHM(C0)2 os CH2Os H(CO)2 'Pr2(X)(1-C ioH 7)2A(co)20s^Os(CO)3H—Os(C0)3(VIII)(CO)3R0---Ru (CO)FcR ,^Ru(CO)3 \^(00)3Ph(XI)P'Prs(C0)3NH(C0)3 Os:■H. —Os.Frr (C0)22(XII)Ru (CO)Ru7undergo a C-H activation only, while i-propyl groups undergo 13 C-Hactivation preferentially. Phenyl and ferrocenyl groups undergo C-Pcleavages with the elimination of benzene and ferrocene, i-propyl groupsare lost as propene.In conclusion, this study has demonstrated that phosphine ligands onRua and 0s3 clusters are not inert to further reactions, and this reactivityhas been used successfully to prepare a large number of unprecedentedtype of complexes.VTABLE OF CONTENTSTitle^Abstract iiTable of Contents^ viList of Tables xxivList of Figures^ xvList of Schemes xxList of Abbreviations^ xxviAcknowledgement xxxDedication^ xxxiiPART ONE: INTRODUCTIONChapter 1 Benzyne, Ferrocyne, and Their Transition Metal Complexes^21.1 Benzyne^ 21.1.1 Historical Background^ 21.1.2 Preparation of Benzyne 51.1.3 Structure and Properties of Benzyne^71.1.4 Reactions of Benzyne^ 81.2 Transition Metal Complexes of Benzyne^ 1 11.2.1 Introduction^ 1 11.2.2 Mononuclear Metal Complexes of Benzyne^ 161.2.2.1 Complexes of early transition metalsand actinoid elements^ 161.2.2.2 Complexes of late transition metals^271.2.2.3 Structure and bonding of benzyne in mononuclearvimetal complexes^ 311.2.3 Metal Cluster Complexes of Benzyne^341.2.3.1 Ruthenium cluster complexes of benzyne^341.2.3.2 Osmium cluster complexes of benzyne 441.2.4 Dinuclear g2-Benzyne (g-o-Phenylene) Complexes^581.2.5 Metal Complexes of Benzdiyne^ 611.3 Ferrocyne and Its Transition Metal Complexes  ^651.3.1 Aromaticity of Ferrocene^ 651.3.2 Ferrocyne^ 6 71.3.3 Transition Metal Complexes of Ferrocyne^70Chapter 2 Syntheses and Structures of Some TrirutheniumTriosmium Phosphine and Arsine Complexes^722.1 Introduction^ 7 22.2 Syntheses and Structures of Some Triruthenium andTriosmium Phosphine and Arsine Complexes^2.2.1 Triruthenium Phosphine and Arsine Complexes^2.2.2 Triosmium Phosphine and Arsine Complexes^2.3 Pyrolytic Reactions of Some Triruthenium and TriosmiumPhosphine and Arsine Complexes2.3.1 Pyrolytic Reactions of Some TrirutheniumPhosphine and Arsine Complexes ^882.3.2 Pyrolytic Reactions of Some TriosmiumPhosphine and Arsine Complexes^ 952.4 Ferrocenylphosphines and Scope of the Present Work^ 100767683viiPART TWO: EXPERIMENTALChapter 3 Experimental^ 1 0 43.1 General Information 1 0 43.1.1 Materials^ 1 0 43.1.2 Reaction conditions^ 1 0 53.1.3 Chromatographic separation^ 10 63.1.4 Characterization^ 1 0 63.2 Preparation of Starting Materials^ 1073.2.1 Preparation of triruthenium dodecacarbonyl Ru3(CO)12 ^ 1073.2.2 Preparation of chlorodi(iso-propyl)phosphine CIPiPr2^ 1083.2.3 Preparation of ferrocenyl ligands^ 1093.2.31 Preparation of ferrocenyldiphenylphosphine PFcPh2^ 1093.2.32 Preparation of diferrocenylphenylphosphine PFc2Ph^ 1103.2.33 Preparation of diethylferrocenylphosphine PEt2Fc^ 1113.2.34 Preparation of ferrocenyldi(iso-propyl)phosphinePFciPr2^ 11 23.2.35 Preparation of n-b utylferrocenylphenylphosphinePnBuFcPh^ 1 1 23.2.36 Preparation of di(tert-butyl)ferrocenylphosphinePtBu2Fc^ 11 33.2.37 Preparation of ferrocene(1,1'-diyl)phenylphosphineFe(C5H4)2PPh^ 1 1 43.2.38 Preparation of ethyldiferrocenylphosphine PEtFc2^ 1153.2.39 Preparation of diferrocenylphenylarsine AsFc2Ph^ 1163.2.310 Preparation of 1,1'-bis(diphenylphosphino)-viiiferrocene Fe(C5H4PPh2)2^3.2.311 Preparation of 1,1'-bis(di-iso-propylphosphino)-ferrocene Fe(C5H4PiPr2)2^ 1 173.2.312 Preparation of 1,1'-bis(diethylphosphino)ferroceneFe(C5H4PEt2)2^ 1 1 83.2.313 Preparation of (3-diethylphosphinoferroceno)-diphenylphospliine (3-PEt2-1-PPh2-05H3)Fe(C5H5)^ 1193.2.314 Preparation of ferrocenylphenylsulfide^ 1193.2.315 Preparation of 1,1'-bis(phenylthio)ferroceneFe(C5H4SPh)2^ 1203.2.316 Preparation of 1,1'-bis(methylthio)ferroceneFe(C5H4SMe)2^ 1213.2.317 Preparation of diferrocenyldisulfide FcSSFc^ 1213.2.318 Preparation of diferrocenylsulfide SFc2 1223.2.319 Preparation of diferrocenylphenylphosphinesulfide S=PFc2Ph^ 12 33.2.320 Preparation of triferrocenylstibine^ 1233.3 Preparation of 0s3 Substitution Complexes 1 2 43.3.1 Preparation of 0s3(C0)11(PFcPh2)^ 1243.3.2 Preparation of 0s3(C0)10(PFcPh2)2 1253.3.3 Preparation of 0s3(C0)11(PFc2Ph)^ 1263.3.4 Preparation of 0s3(C0)10(PFc2Ph)2 1263.3.5 Preparation of 0s3(C0)11(PEt2Fc)^ 1273.3.6 Preparation of 0s3(C0)11(PFciPr2) 1283.3.7 Preparation of 0s3(C0)11(Pl-Bu2Fc)^ 1293.3.8 Preparation of 0s3(C0)11(PEtFc2) 1303.3.9 Preparation of 0s3(C0)10[Fe(PiPr2)2]and117ix(0s3(C0)11)2[Fc'(PiPr2)2]^ 1313.4 Preparation of Ru3 Substitution Complexes^ 1313.4.1 Preparation of Ru3(CO)i1(PFcPh2) 1323.4.2 Preparation of Ru3(C0)10(PFcPh2)2^ 1323.4.3 Preparation of Ru3(C0)9(PFcPh2)3 1333.4.4 Preparation of Ru3(C0)11(PFc2Ph)^ 1343.4.5 Preparation of Ru3(CO)9(PFc2Ph)3 1353.4.6 Preparation of Ru3(CO)i i(PEt2Fc)^ 1353.4.7 Preparation of Ru3(CO)1 I(PFciPr2) 1363.4.8 Preparation of Ru3(C0)9(PFciPr2)3^ 1373.4.9 Preparation of Ru3(C0)11(PtBu2Fc) 1373.4.10 Preparation of Ru3(CO)1 i(PnBuFcPh)^ 1383.4.11 Preparation of Ru3(C0)10[Fc'(PPh2)2] 1383.4.12 Preparation of Ru3(C0)10[Fe(PFcPh)2]^ 1393.4.13 Preparation of Ru3(C0)10[Fc'(PtBuPh)2] 1403.4.14 Preparation of Ru3(C0)10[Fc'(PiPr2)2]^ 1403.4.15 Preparation of Ru3(C0)9[Fe(PiPr2)2](PFc2Ph)^ 1413.4.16 Preparation of Ru3(C0)9[Fe(PiPr2)2](PEtFc2)^ 1413.4.17 Preparation of Ru3(CO)1 i(PEtFc2)^ 1423.5 Pyrolysis of 0s3 Complexes^ 1423.5.1 Pyrolysis of 0s3(C0)11(PFcPh2)^ 1423.5.2 Pyrolysis of 0s3(C0)9(PFc)(C61 .14) (239)^ 1463.5.3 Pyrolysis of 0s3(C0)10(PFcPh2)2 1473.5.4 Pyrolysis of 0s3(C0)11(PFc2Ph)^ 1493.5.5 Pyrolysis of 0s3(C0)10(PFc2Ph)2 1533.5.6 Pyrolysis of 0s3(C0)11(PEt2Fc)^ 1553.5.7 Pyrolysis of 0s3(C0)8(H)2[(C5H3PEt2)Fe(C5H4)] (269)^ 1563.5.8 Pyrolysis of 0s3(C0)12 with PEt2Fc in 1:2 molar ratio^ 1563.5.9 Pyrolysis of 0s3(C0)11(PFciPr2)^ ••1583.5.10 Pyrolysis of 0s3(C0)12 with PnBuFcPh^ 1603.5.11 Pyrolysis of 0s3(C0)12 with PtBu2Fc 1643.5.12 Pyrolysis of 0s3(C0)12 with Fe(C5H4)2PPh^ 1663.5.13 Pyrolysis of 0s3(C0)12 with PEtFc2 1663.5.14 Pyrolysis of 0s3(C0)11(PEtFc2)^ 1703.5.15 Pyrolysis of 0s3(C0)12 with AsFc2Ph 1713.5.16 Pyrolysis of 0s3(C0)10[Fc'(PiPr2)2]^ 1733.5.17 Pyrolysis of (0s3(C0)11)2[Fc'(PiPr2)21 1763.5.18 Pyrolysis of 033(C0)12 with P(1-C1oll7)3^ 1773.5.19 Pyrolysis of 0s3(C0)12 with As(1-C107)3 1783.6 Pyrolysis of Rua Complexes^ 1793.6.1 Pyrolysis of Ru3(C0)11(PFcPh2)^ 1793.6.2 Pyrolysis of Ru3(C0)10(PFcPh2)2 1833.6.3 Pyrolysis of Ru3(C0)9(PFcPh2)3^ 1833.6.4 Pyrolysis of Ru3(CO)11(PFc2Ph) 1853.6.5 Pyrolysis of Ru3(C0)12 with PFc2Ph^ 1883.6.6 Pyrolysis of Ru3(C0)12 with PEt2Fc 1893.6.7 Pyrolysis of Ru3(C0)12 with PEtFc2^ 1903.6.8 Pyrolysis of Ru3(C0)10[Fc . (PPh2)2] 1903.6.9 Pyrolysis of Ru3(C0)10[Fc'(PtBuPh)21^ 1923.6.10 Pyrolysis of Ru3(C0)10[Fe(PiPr2)21 1943.6.11 Pyrolysis of Ru3(C0)12 with p(1-c10-17)3^ 1963.6.12 Pyrolysis of Ru3(C0)12 with As(1-C1 0117)3 1973.6.13 Pyrolysis of Ru3(C0)12 with SFcPh^ 197xi3.6.14 Pyrolysis of Ru3(C0)12 with SPh2^ 198PART THREE: RESULTS AND DISCUSSIONChapter 4 Pyrolysis of Triosmium Complexes ContainingFerrocenylphosphine Ligands^ 2004.1 Pyrolysis of 0s3(C0)11(PFcPh2) 2004.2 Pyrolysis of 0s3(C0)10(PFcPh2)2^ 2084.3 Pyrolysis of 0s3(C0)11(PFc2Ph) 2184.4 Pyrolysis of 0s3(C0)10(PFc2Ph)2^ 2374.5 Pyrolysis of 0s3(C0)1 1(PEt2Fc) 2394.6 Pyrolysis of 0s3(C0)12 with PEt2Fc in 1:2 molar ratio^2534.7 Pyrolysis of 0s3(C0)11(PFciPr2)^ 2544.8 Pyrolysis of 0s3(C0)12 with PnBuFcPh 2664.9 Pyrolysis of 0s3(C0)12 with PtBu2Fc^ 2734.10 Pyrolysis of 0s3(C0)12 with Fe(C5H4)2PPh^2784.11 Pyrolysis of 0s3(C0)12 with PEtFc2^ 2824.12 Pyrolysis of 0s3(C0)12 with AsFc2Ph 2894.13 Pyrolysis of 0s3(C0)10[Fc'(PiPr2)2]^ 2974.14 Pyrolysis of 0s3(C0)12 with P(1-C10117)3 3194.15 Pyrolysis of 0s3(C0)12 with As(1-C10H7)3^321Chapter 5 Pyrolysis of Triruthenium Complexes ContainingFerrocenylphosphine Ligands^5.1 Pyrolysis of Ru3(CO)1 (PFcPh2)5.2 Pyrolysis of Ru3(C0)10(PFcPh2)2^325325336Xii5.3 Pyrolysis5.4 Pyrolysis5.5 Pyrolysis5.6 Pyrolysis5.7 Pyrolysis5.8 Pyrolysis5.9 Pyrolysisof Ru3(C0)9(PFcPh2)3^of Ru3(CO)i1(PFc2Ph)^of Ru3(C0)12 with PEt2Fc ^of Ru3(C0)12 with PEtFc2 ^of Ru3(C0)10[Fc'(PPh2)2]^of Ru3(C0)10[Fc'(PtBuPh )2]of Ru3(C0)10[Fe(PiPr2)2] ^336343353354356 3603663783803823835.10 Pyrolysis of Ru3(C0)12 with P(1-C10H7)3 ^5.11 Pyrolysis of Ru3(C0)12 with As(1-C10H7)35.12 Pyrolysis of Ru3(C0)12 with SFcPh^5.13 Pyrolysis of Ru3(C0)12 with SPh2^Chapter 6 Ferrocenyl Ligands and Their Triosmium and TrirutheniumComplexes^ 3886.1 Syntheses and Characterization of Ferrocenyl Ligands^3883883893956.2.1 Syntheses of triosmium ferrocenylphosphinecomplexes^6.2.2 Characterization of triosmium ferrocenylphosphinecomplexes^6.3 Syntheses and Characterization of TrirutheniumFerrocenylphosphine Complexes^6.3.1 Syntheses of triruthenium ferrocenylphosphine6.1.1 Syntheses of ferrocenyl ligands^^6.1.2 Characterization of ferrocenyl ligands ^6.2 Syntheses and Characterization of TriosmiumFerrocenylphosphine Complexes^395396399complexes^ 3 9 96.3.2 Characterization of triruthenium ferrocenyl-phosphine complexes^ 4006.4 Structures of Triosmium and Triruthenium Ferrocenyl-phosphine Complexes^ 4036.4.1 Isomerism in the disUbstituted complexesM3(CO)i0L2^ 4 0 36.4.2 Molecular structure of 0s3(C0)10(PFc2Ph)2 (378)^4056.5 General Comments on the Pyrolytic Reactions andCharacterization of Pyrolysis Products^ 4086.5.1 General comments^ 4086.5.2 1 H NMR spectra of the pyrolysis products^4096.5.3 3 1 P NMR spectra of the pyrolysis products 4146.6 Iron (ferrocene)-metal Bonding Interactions inTriosmium and Triruthenium Complexes^417PART FOUR: SUMMARY AND FUTURE PROSPECTSChapter 7 Summary and Future Prospects^ 4247.1 Summary of the Present Work 4247.2 Suggestions for Future Work^ 43 67.3 Approaches to Mononuclear Ferrocyne Complexes^4417.4 Other Topics of Interest^ 442References^ 44 4XivList of FiguresFigure^ PageFigure 1.1 Calculated bond lengths (A) and bond angles ( 0 )in benzyne^ 8Figure 1.2 Numbering of complexes (106)^ 3 7Figure 1.3 Bond lengths (A) and angles ( 0 ) of benzyne in (106b)^39Figure 1.4 Numbering of complexes (107)^ 4 0Figure 1.5 Bond lengths (A) of benzyne in complexes (107c)^41Figure 1.6 Isomers of complexes (122) and (123)^ 4 9Figure 1.7 Positional isomers of benzyne complexes derivedfrom toluene and chlorobenzene (X=CH3, Cl)^ 5 1Figure 1.8 Numbering and structural types of 0s3 benzynecomplexes^ 5 2Figure 1.9 Structures of (121b), (107a), and (108a) withCO groups being omitted^ 5 6Figure 1.10 Comparison of the bond lengths and angles of the1,4-benzdiyne moieties in (148a) and (151)^65Figure 4.1 300 MHz 1 H NMR spectrum of complex (239) 200Figure 4.2 ORTEP diagram of complex (239)^ 201Figure 4.3 A proposed structure for complex (240)^204Figure 4.4 ORTEP diagram of complex (242)^ 206Figure 4.5 Proposed structures for complexes (243) and (244)^207Figure 4.6 ORTEP diagram of complex (245)^ 210Figure 4.7 Proposed structures for complexes (246) and (247)^212Figure 4.8 Proposed structures for complexes (248) and (249)^213xvFigure 4.9 Proposed structures for complex (250)^214Figure 4.10 400 MHz 1 H NMR spectrum of complex (251)^2 15Figure 4.11 ORTEP diagram of complex (251)^ 2 16Figure 4.12 400 MHz 1 H NMR spectrum of complex (252)^219Figure 4.13 ORTEP diagram of complex (252)^ 220Figure 4.14 Proposed structures for complexes (253), (254),and (255)^ 2 2 3Figure 4.15 Possible structures for complexes (256), (257),and (258)^ 2 2 4Figure 4.16 300 MHz 1 H NMR spectrum of complex (257)^225Figure 4.17 Possible structures for complexes (259) and (260)^226Figure 4.18 500 MHz 1 H NMR spectrum of complex (261)^227Figure 4.19 ORTEP diagram of complex (261)^ 2 2 8Figure 4.20 400 MHz 1 H NMR spectrum of complex (263)^230Figure 4.21 ORTEP diagram of complex (263)^ 231Figure 4.22 Possible structures for complexes (264), (265),and (266)^ 239Figure 4.23 200 MHz 1 H NMR spectrum of complex (269)^240Figure 4.24 ORTEP diagram of complex (269a)^ 240Figure 4.25 ORTEP diagram of complex (269b) 241Figure 4.26 Proposed structures of complexes (268) and (270)^243Figure 4.27 200 MHz 1 H NMR spectrum of complex (267)^244Figure 4.28 Four types of hydride arrangement in complex (227a)^245Figure 4.29 Possible structures for complex (267)^247Figure 4.30 Possible structures for complexes (272), (273),and (274)^ 2 5 4Figure 4.31 300 MHz 1 H NMR spectrum of complex (274)^255xviFigure 4.32 300 MHz 1 H NMR spectrum of complex (275)^256Figure 4.33 Proposed structures for complexes (274), (275),and (276)^ 2 5 7Figure 4.34 400 MHz 1 H NMR spectrum of complex (278)^258Figure 4.35 ORTEP diagram of complex (278)^ 2 5 9Figure 4.36 Possible structures for complexes (277), (279),and (280)^ 2 6 1Figure 4.37 400 MHz 1 H NMR spectrum of complex (279)^261Figure 4.38 Possible structures for complexes (281), (282),and (283)^ 2 6 7Figure 4.39 Possible structures for complexes (284) and (285)^268Figure 4.40 Possible structures for complexes (287), (288),(289), and (290)^ 270Figure 4.41 Possible structures for complexes (291) and (292)^271Figure 4.42 Possible structures for complexes (293) and (294)showing one type of PnBuFcAh coordination site^272Figure 4.43 300 MHz 1 H NMR spectrum of complex (295)^274Figure 4.44 Possible structures for complexes (295) and (296)^275Figure 4.45 Possible structures for complexes (297), (298),and (299)^ 276Figure 4.46 ORTEP diagram of complex (300)^ 279Figure 4.47 Possible structures for complexes (301) and (302)^283Figure 4.48 Possible structures for complexes (303) and (304)^284Figure 4.49 Possible structures for complexes (306), (307),and (309)^ 285Figure 4.50 ORTEP diagram of complex (308)^ 286Figure 4.51 Possible structures for complexes (312) and (313)^290xviiFigure 4.52 300 MHz 1 H NMR spectrum of complex (312)^291Figure 4.53 ORTEP diagram of complex (315)^ 2 9 2Figure 4.54 200 MHz 1 H NMR spectrum of complex (317)^294Figure 4.55 Possible structures for complexes (317) and (318)^295Figure 4.56 300 MHz 1 H NMR spectrum of complex (320)^295Figure 4.57 Possible structures for complexes (320) and (321)^296Figure 4.58 Possible structures for complexes (322) and (324)^298Figure 4.59 300 MHz 1 H NMR spectrum of complex (323)^298Figure 4.60 ORTEP diagram of complex (323)^ 300Figure 4.61 ORTEP diagram of complex (325) 302Figure 4.62 ORTEP diagram of complex (326)^ 306Figure 4.63 400 MHz 1 H NMR spectrum of complex (329)^308Figure 4.64 ORTEP diagram of complex (329)^ 309Figure 4.65 ORTEP diagram of complex (330) 31 1Figure 4.66 Possible structures for complexes (333) and (334)^320Figure 4.67 ORTEP diagram of complex (336)^ 322Figure 5.1 121.4 MHz 31 P NMR spectrum of a product mixture^325Figure 5.2 300 MHz 1 H NMR spectrum of complex (337)^326Figure 5.3 300 MHz 1 H NMR spectrum of complex (340) 327Figure 5.4 Possible structures for complexes (337), (340),and (341)^ 328Figure 5.5 121.4 MHz31 P NMR spectrum of complex (342)^329Figure 5.6 121.4 MHz variable temperature 31 P NMR spectrumof complex (342)^ 330Figure 5.7 ORTEP diagram of complex (342)^ 331Figure 5.8 Possible structures for complexes (338) and (343)^335Figure 5.9 121.4 MHz 3 1 P NMR spectrum of a mixture ofxviii(338) and (344)^ 337Figure 5.10 ORTEP diagram of complex (344)^ 3 3 8Figure 5.11 Possible structures for complex (345) 341Figure 5.12 300 MHz 1 1-1NMR spectrum of complexes (346)and (347)^ 3 4 1Figure 5.13 Possible structures for complexes (346) and (347)^342Figure 5.14 ORTEP diagram of complex (350)^ 344Figure 5.15 ORTEP diagram of complex (351) 3 49Figure 5.16 Two possible structures for complex (352)^351Figure 5.17 ORTEP diagram of complex (355)^ 35 4Figure 5.18 Possible structures for complexes (358) and (360)^359Figure 5.19 Possible structures for complexes (363) and (364)^361Figure 5.20 ORTEP diagram of complex (365)^ 362Figure 5.21 A possible structure for complex (366)^365Figure 5.22 Stereo ORTEP diagram of complex (368) 367Figure 5.23 Possible structures for complexes (369) and (370)^369Figure 5.24 300 MHz 1 H NMR spectrum of complex (370)^371Figure 5.25 ORTEP diagram of complex (371)^ 373Figure 5.26 Likely structures for complexes (372) and (373)^379Figure 5.27 300 MHz 1 H NMR spectrum of complex (374)^381Figure 5.28 A most likely structure for complex (375) 383Figure 5.29 300 MHz 1 H NMR spectrum of complex (376)^384Figure 5.30 ORTEP diagram of complex (376)^ 3 8 5Figure 6.1 ORTEP diagram of complex (378) 407xixList of SchemesScheme^ PageScheme 1-1 The preferred formation of resorcinol from benzene-1,4-disulfonate or 4-bromobenzenesulfonate^2Scheme 1-2 The first aryne intermediate proposed in arearrangement reaction^ 3Scheme 1-3 Reaction of fluorobenzene-(1- 14C) with phenyllithium^4Scheme 1-4 Reactions of 1- and 2-halonaphthalenes with lithiumpiperidide^ 5Scheme 1-5 Synthesis of cubane by using (11 4 -C4H4)Fe(C0)3(41) as a source of free cyclobutadiene^ 1 3Scheme 1-6 Reaction of benzyne precursors with Pt(0) complexes^ 14Scheme 1-7 Influence of Ag+ on the cycloaddition of benzyneto benzene^ 15Scheme 1-8 Generation and trapping of [Cp2ri(C6H4)] (54)^ 17Scheme 1-9 Aryl group exchange in Cp2Zr(aryl)2^ 18Scheme 1-10 Reactions of [Cp2Zr(C6H4)] (60) 19Scheme 1-11 Reactions of Cp2Zr(C6H4)(PMe3) (70)^ 19Scheme 1-12 Olefin exchange in zirconindan complexes^20Scheme 1-13 Synthesis and reactions of [Cp2Zr(aryne)] (72)^21Scheme 1-14 Synthesis of dihydrocyclobutabenzenes from (72)^21Scheme 1-15 Hydrogen/deuterium exchange in Cp2Zr(D)(Ph)^22Scheme 1-16 Reactions of [Cp2Zr(C6H4)] (60) with Ph3P=CH2^23Scheme 1-17 Preparation of Ni(Cy2PCH2CH2PCy2)(C6H4) (96)^28Scheme 1-18 Preparation of (2-halogenphenynnickel(II)xxhalide complexes^ 2 8Scheme 1-19 Reactions of Ni(Cy2PCH2CH2PCy2)(C6H4) (96)^30Scheme 1-20 Preparastion and reactions of (PMe3)4Ru(11 2-C6H4) (99)^3 1Scheme 1-21 Reactions of benzyne complexes (106a), (107a),and (108)^ 43Scheme 1-22 Two rapid intramolecular processes proposed for0s3(1.13-C6H4)(AsMe2)2(C0)7^ 46Scheme 1-23 Synthesis of the benzdiyne complexes (146) and (147)^62Scheme 1-24 Reactions of the benzdiyne complexes (148a) and(148b)^ 6 3Scheme 1-25 Some typical reactions of ferrocene (153)^67Scheme 1-26 Some reactions of mono- and 1,1'-dilithiatedferrocenes^ 6 8Scheme 1-27 A possible pathway for the reasction of FcCl withnB uLi not involving a ferrocyne intermediate^69Scheme 1-28 Reactions of a substituted chloroferrocene with nBuLi ^70Scheme 2-1 The proposed mechanism .for BPK catalyzed mono-substitution of Ru3(C0)12^ 77Scheme 2-2 A possible reaction sequence for the formation of(218) from Ru3(C0)8(dPPIn)2^ 92Scheme 2-3 A proposed reaction sequence for the pyrolysis ofRu3(C0)10(bPPf)^ 9 4Scheme 2-4 Proposed mechanism for the pyrolytic reactions0s3(C0)11(PRPh2)^ 98Scheme 4-1 A possible reaction sequence for the pyrolysis of0s3(C0)11(PFcPh2)^ 2 33Scheme 4-2 A possible reaction sequence for the pyrolysis ofxxi0s3(C0)11(PFcPh2)^ 234Scheme 4-3 A possible reaction sequence for the pyrolysis of0s3(C0)11(PFcPh2)^ 235Scheme 4-4 A possible reaction sequence for the pyrolysis of0s3(C0)11(PFcPh2)^ 236Scheme 4-5 A possible reaction sequence for the pyrolysis of0s3(C0)11(PEt2Fc)^ 249Scheme 4-6 A possible reaction sequence for the pyrolysis of0s3(C0)11(PEt2Fc)^ 250Scheme 4-7 A possible reaction sequence for the pyrolysis of0s3(C0)11(PEt2Fc)^ 251Scheme 4-8 A possible reaction sequence for the pyrolysis of0s3(C0)11(PEt2Fc)^ 252Scheme 4-9 A possible reaction sequence for the pyrolysis of0s3(C0)11(PFciPr2)^ 263Scheme 4-10 A possible reaction sequence for the pyrolysis of0s3(C0)11(PFciPr2)^ 2 6 4Scheme 4-11 A possible reaction sequence for the pyrolysis of0s3(C0)11(PFciPr2)^ 265Scheme 4-12 A possible reaction sequence for the pyrolysis of0s3(C0)12 and PtBu2Fc^ 277Scheme 4-13 A possible reaction sequence for the pyrolysis of0s3(C0)12 and Fe(C5H4)2PPh^ 282Scheme 4-14 A possible reaction sequence for the pyrolysis of0s3(C0)10[Fc'(PiPr2)2]^ 314Scheme 4-15 A possible reaction sequence for the pyrolysis of0s3(C0)10[Fc'(PiPr2)2]^ 3 1 5Scheme 4-16 A possible reaction sequence for the pyrolysis of0s3(C0)10[Fc . (PiPr2)2]^ 317Scheme 4-17 A possible reaction sequence for the pyrolysis of0s3(C0)10[Fc'(PiPr2)2]^ 3 1 8Scheme 5-1 A possible reaction pathway for the formationof complex (371)^ 374Scheme 5-2 Possible reaction sequence for the pyrolysis ofRu3(C0)10[Fc'(PiPr2)2]^ 375Scheme 5-3 Possible reaction sequence for the pyrolysis ofRu3(C0)10[Fc'(PiPr2)2]^ 377Scheme 6-1 An exchange pathway of two unsymmetricalstructures^ 4 0 4Scheme 6-2 A postulated electrophilic substitution reactionpathway involving initial attack of the electrophileson the central metal atom^ 418Scheme 7-1 A hypothetical route to a ferrocyne complex^441List of TablesTable^ PageTable 1-1 Anionic bis(aryne) complexes isolated from reactionsof early transition metal pentahalides witharyllithium reagents^ 2 5Table 1-2 Comparison of C-C bond lengths in metal benzynecomplexes with those in free benzyne [27]^32Table 1-3 Some important structural parameters forcomplexes (106)^ 3 8Table 1-4 Important bonding parameters for complexes (107)^40Table 1-5 Important bonding parameters for the determinedstructures of 0s3 benzyne complexes^ 5 3Table 2-1 Structural data for Ru3(C0)12 (167) and0s3(C0)12 (168)^ 76Table 2-2 Ru-Ru bond distances for some Ru3(C0)10(L-L)and Ru3(C0)8(L-L)2 complexes^ 83Table 4-1 Hydride NMR resonances for complexes (277),(228), (267), (269), (271), and (272)^ 246Table 6-1 Comparison of measured and calculated31p NMR chemical shifts^ 39 1Table 6-2 Major features of the EI mass spectra offerrocenyl ligands^ 39 3Table 6-3 3 1 P and hydride NMR resonances for complexes0s3(C0)8(H)2[(C5H3PR2)Fe(C5H4)]^ 411xxivTable 6-4 Hydride resonances for complexesM3(C0)8R 1 -CI 0H7)2E( 1 -CI 0H5)]^Table 6-5 31 P and hydride NMR resonances for complexes0s3(C0)10(H)2[(C5H4PR2)Fe(C5H3)]^412413xxvList of AbbreviationsA^angstroma, b, c^unit cell dimensionsa, (3, y^unit cell anglesanal.^analysisatm^standard atmospherebra^broad multipletbppf^bis(diphenylphosphino)ferrocene Fe(C5H4PPh2)2BPK^sodium benzophenone ketyl radical anion NalPhCOP111 -bs^broad singletnB u^n-butyl -CH2CH2CH2CH3tBu^tert-butyl -C(CH3)3Bz^benzyl -CH2C6H5°C^degrees centigrade (Celsius)13C^carboncalc.^calculatedcm^centimeter (10 -2 m)cm3^cubic centimeter (milliliter; 10 -6 m 3 )Cp^cyclopentadienyl C5H5 or C5H4 or C5H3Cp*^pentamethylcyclopentadienyl C5Me5Cy^cyclohexyl -C6Hd^doublet8^chemical shift• degree (angle)DCI^Desorption Chemical Ionizationdd^doublet of doubletxxv idmpm^bis(dimethylphosphino)methane Me2PCH2PMe2dppa^bis(diphenylphosphino)acetylene Ph2Pa-CPPh2dpae^bis(diphenylarsino)ethane Ph2AsCH2CH2AsPh2dpam^bis(diphenylarsino)methane Ph2AsCH2AsPh2dppb^bis(diphenylphosphino)butane Ph2PCH2CH2CH2CH2PPh2dppe^bis(diphenylphosphino)ethane Ph2PCH2CH2PPh2cis-dppee cis-bis(diphenylphosphino)ethylene cis-(Ph2P)CH=CH(PPh2)dppm^bis(diphenylphosphino)methane Ph2PCH2PPh2dppp^bis(diphenylphosphino)propane Ph2PCH2CH2CH2PPh2Dcaic^calculated densityEI^Electron Impact or IonizationEt^ethyl -CH2CH 3FAB^Fast Atom BombardmentFc^ferrocenyl (C5H4)Fe(C5H5)Fc'^ferrocenyl (C5H4)Fe(C5H4)ffars^1 ,2 -bis(dimethylarsino)-3,3,4,4-tetrafluorocyclobutenef6fos^1,2-bis(diphenylphosphino)-3,3,4,4,5 ,5 -hexafluorocyclopentenef4fos^1,2-bis(diphenylphosphino)-3,3,4,4-tetrafluorocyclobuteneg gram1 H^protonh hourhapticityHz^HertzIR^infra-redJ^coupling constantL^LiterL general monodentate phosphine or arsinexxviiL-L^general bidentate phosphine or arsineM^general transition metalm^multipletm^millibridging bonding modem/e^mass over charge ratioMe^methyl -CH3mg^milligramMHz^megahertz (10 6 Hz)min^minutemL^millilitermmol^millimolemol^moleNMR^Nuclear Magnetic Resonance31p^phosphorusP+^parent ionPh^phenyl -C6H5ppm^parts per millionPPN+^bis(triphenylphosphino) iminiutn (Ph3P)2N+npr^n-propyl -CH2CH2CH3iPr^iso-propyl -CH(CH3)2Py^pyridyl -05H5Nq^quartetR^residualR, RI, R'^aryl, ferrocenyl, alkylRw^weighted residuals^singletxxviiit^triplettd^triplet of doubletTHE^tetrahydrofuranTLC^thin layer chromatographyTMEDA^tetramethylethylenediamine Me2NCH2CH2NMe2UV-vis^ultraviolet-visibleV^unit cell volumeX^halogen or halide F, Cl, Br, IZ^number of molecules in a unit cellACKNOWLEDGEMENTFirst of all, I wish to express my sincere gratitude to my researchsupervisor, Professor William R. Cullen, for his advice, guidance, patience,encouragement, and assistance during the course of this work. It has beena pleasant and rewarding experience. I also thank him for financialsupport during the preparation of this thesis.I am very grateful to Professor Brian R. James and Mr. ChristopherSimpson for reading the manuscript of this thesis.Merci beaucoup to Dr. Steven J. Rettig for his excellent crystalstructure determinations and for his help! He helped to make chemistry somuch fun for me!I am grateful to the technical staff of this department, in particularDr. S. 0. Chan, Mrs. M. Austria, and Mrs. L. Darge for the assistance of NMRexperiments, and Mr. P. Borda for his expert micro-analyses. I am alsograteful to Dr. Graham Ball for all the 500 MHz NMR spectra.My special thanks go to Professor Michael I. Bruce, Dr. EugeneWickenheiser, Dr. Cashman Hampton, Dr. Paul Wood, and Mr. Olaf Kuhl forfruitful discussions. Dank sehr to Mr. Kuhl for his help in performing anumber of pyrolysis experiments.I thank Mrs. Akiko Kadono, Mrs. Jafariah Jaafar, Mr. Xiao-chun Le,Mrs. Xing-fang Li, Mr. Olaf Kuhl, and Dr. William Maher for theirfriendship, and Mr. Kuhl and Dr. Maher for sharing precious tea time withme.It is a great pleasure to thank my friendly and cooperativecolleagues: Dr. G. J. Kang, Dr. N. F. Han, Dr. D. Hettipathirana, Dr. M. Dodd, Dr.L. Z. Zhu, Mrs. A. Talaba, Mr. H. L. Zhang, Mr. 0. Abiodun, Mr. B. Nwata, Ms.xxxA. Tsang, Mrs. C. Mudalige, Mr. S. Pergantis, Mr. M. H. Luo, Mr. J. Nelson,and Mr. H. Li. Special thanks to Mrs. A. Talaba for tolerating me playingBeethoven in the laboratory.I express my greatest thanks to my beloved wife for her everlastinglove! Without her, the whole world is a hell to me, and I cannot breathe!I also wish to thank the University of British Columbia for providingUniversity Graduate Fellowships from 1988 to 1992, the Department ofChemistry for providing teaching assistantships, and the Department ofEducation of my motherland, the People's Republic of China, for supportingme in the first year of the programme. I missed my country very much!There is no place like home!Finally, I must also thank Ludwig V. Beethoven, whose soul livesforever, for his inspiring music, something that balms my soul andnurtures my spirit!DEDICATIONTo my beloved Ying-minDu bist wiz eine 13Eurne,So hoEd und salon und rein;-1„cft scrum' dick an , and WeftrnutSchteicht tnvr ins 3-ferz hinetn.nix ist, nis ob id" die 3-LandeAufs 3-Ectupt dir Eggert salt',tetend, dat3 Gott di.cb. erhatteSo rein und sawn and hofd.3-1einrich 3 LeinePART ONE: INTRODUCTIONSO3KBrSO3KSO3K SO3KSO3KresorcinolChapter 1 Benzyne, Ferrocyne, and TheirTransition Metal Complexes1.1 Benzyne1.1.1 Historical BackgroundSoon after Kekule [1] and Wurtz [2] discovered the transformation ofsodium benzenesulfonate to phenol by molten alkali in the 1860 .s, thepreferred formation of resorcinol from the alkaline fusion of benzene-1,4-disulfonate [3] or 4-bromobenzenesulfonate [4] was reported (Scheme 1-1).It was also found that the action of the N-alkali-derivatives of ammonia orScheme 1-1 The preferred formation of resorcinol from benzene-1,4-disulfonate or 4-bromobenzenesulfonate.2amines upon aryl halides leads to substitution with rearrangement [5,6].The first interpretation of these rearrangements in nucleophilicaromatic substitution reactions appeared in 1902 when Stoermer andKahlert [7] rationalized the formation of 2-ethoxycoumarone • from thereaction of 3-bromocoumarone with sodium ethoxide in terms of the aryneintermediate (1), Scheme 1-2. OEt( 1 )Scheme 1-2 The first aryne intermediate proposed in a rearrange-ment reaction.In 1927, Bachmann and Clarke [8] ascribed the small amount oftriphenylene formed on treating chlorobenzene with sodium to atrimerization of 'phenylene radicals', C6H4. Wittig [9] postulated the 'dipolarphenylene" (2) as intermediate in the formation of o-lithiobiphenyl fromthe reaction of fluorobenzene with phenyllithium. He also discussed thestructure of a neutral, triply bonded aryne (3). The dipolar phenylene (2)was also used by Morton et al. [10] to interpret the reaction ofchlorobenzene with amylsodium.(2)^(3)3Ph PhScheme 1 - 3 Reaction of fluorobenzene-(1_ 14C) with phenyllithium.LiLi(4) PhPhRoberts et al. [111 studied the isotope distribution in aniline obtainedfrom the reaction of chlorobenzene-(1- 14C) with potassium amide in liquidammonia and coined the name "benzyne" for the proposed intermediate. Arelated reaction of fluorobenzene-(1- 14C) with phenyllithium, studied byJenny et al. [12], is shown in Scheme 1-3. The 14C labelled benzyne inter-mediate (4) reacts in the indicated proportions. The small deviation from a50:50 product ratio can be attributed to a kinetic isotope effect.Huisgen et al. [131 found that both o- and m-fluoroanisole affordcommon products (5) and (6) upon treatment with phenyllithium andcarbon dioxide. Similar reactions with a- and A-fluoronaphthalenes yield(7) and (8) in the same ratio ((9) was also obtained from the (3-isomer).Bunnett et al [141 and Sauer et al 1151 found that lithium piperidideconverts 1 - and 2-halonaphthalenes to a- and f3-naphthylpiperidines in aconstant isomer ratio (Scheme 1-4, X=CI, Br, I). These results indicate acorn mon inter mediate 1,2 -naphthyne (10).The involvement of 'free' benzyne in some solution reactions is4COONPhPhCOOH(6)^(7)Ph(8)'(5 )NC5H10NC 5H io(10)OMe^OMe^Ph^COOHScheme 1-4 Reactions of 1- and 2-halonaphthalenes with lithiumpiperidide.implied from the results of a competition experiment [16]. When bothfuran and cyclohexadiene are present, benzyne generated by severaldifferent routes (Section 1.1.2) affords Diels-Alder addition products (11)and (12) in the same ratio.1.1.2 Preparation of BenzyneBenzyne may be prepared in a variety of ways. Dehalogenation ofhalobenzenes with strong bases such as amide ion or phenyllithium, asdiscussed above, remains a convenient and important route to benzyne.5COOHPh(9) (13)(12)(14) (15) (16)(11)COONNH 2COO-NN+Treatment of o-dihalobenzenes such as (13) with magnesium also producesbenzyne [171.The action of heat or light upon the zwitterionic salt (14) leads tobenzyne [181. A modification of this method involves the in situdiazotisation of anthranilic acid (15) with i-amyl nitrite in methylenechloride [191. Photolysis of o-diiodobenzene [201 and of the iodonium salt(16) [211 produces benzyne. Thermolysis of phthalic anhydride [221 and ofthe benzothiadiazole (17) [23] also affords benzyne.Benzyne can be generated by the lead tetraacetate oxidation of 1-amino-triazolo (18) [241, and by the reduction of nitroso compounds suchas (19) with ethoxydiphenylphosphine [251. A particularly gentle methodN\ ^N_‘•N^•N •NN N NN N^N\^\ \NH2 NO Li N —N=N—NHTs(18)^(19)^(20)6(22) (23)is to cover the salt (20) with tetrahydrofuran at 0°C and to allow themixture to warm up to room temperature to produce benzyne [261.1.1.3 Structure and Properties of BenzyneEarlier descriptions suggest two formulations for benzyne. In thefirst of these, two carbon atoms have sp hybrid orbitals and there is a truetriple bond (21). Severe distortions are necessary to obtain appreciableoverlap between the sp 2 - and sp-hybrid orbitals, accounting for the highreactivity of benzyne. A resonance structure can be written as in (22).In the alternative description, the benzene ring retains its a-bondskeleton with sp 2 hybridization and the geometry of a regular hexagon(23). The two electrons, forming the special bond of benzyne, occupy twosp 2 orbitals within the plane of the carbon atoms. The binding overlap ofthese orbitals will be very weak because they are not parallel but includean angle of 60 0. Such a model would also account for the high reactivity ofbenzyne. If the electrons have parallel spins, a triplet state will result.However, this is an unlikely description for the ground state benzyne sincethere is no n bonding involved.The resonance structure (22) has generally been accepted as theground state representation of benzyne [271. Benzyne has been subjectedto theoretical calculations at various levels of sophistication [28-33]. Figure71.1 shows bond lengths and angles obtained from an ab-initio 6-31G*-based calculation [321; the lengths are corrected values based on thestandard C=C and CEC bond lengths of 1.334 and 1.203 A, respectively. Theacetylenic bond length C1-C2 generally falls in the range 1.22-1.25 A andis thus only slightly longer than a normal C C bond.4^21.402 ♦ 1.393Figure 1.1 Calculated bond lengths (A) and bond angles (°) in benzyne.The mass and UV spectra of benzyne can be measured by the use ofvarious flash techniques [34,351.The microwave spectrum of benzyne in the gas phase can besimulated by using the ab-initio geometry, and the predicted andobserved rotational constants agree to within 1% [361. The IR spectrum ofbenzyne, measured in an argon matrix, shows a CEC stretching band at2085 cm -1 , which is only slightly lower than the value of ca. 2200 cm -1 inacyclic alkynes [37].1.1.4 Reactions of BenzyneBenzyne is a short-lived species, and the short lifetime of freebenzyne was first demonstrated by passing argon saturated with di-(o-8.^(24)iodophenyl)mercury through a hot zone at 750°C and observing the abilityof the emerging gas to add to furan as a function of the distance fromwhere it was formed [38]. It can be observed by using spectroscopicmethods in an argon matrix at low temperatures or at low pressure in thegas phase as mentioned above [36,37,39-41]. In the absence of otherreagents, benzyne dimerizes to biphenylene (24) and in some casestrimerizes to triphenylene (25) 134,35,42].N(25) 0^(26)OHBenzyne often acts as an electron deficient species. A number ofaddition reactions of metallorganic substances and metal amides tobenzyne have already been mentioned (Section 1.1.1). If one of the carbonatoms adjacent to the benzyne triple bond carries an atom or group that isnucleophilic, cyclization readily occurs and a wide variety of heterocycliccompounds can be prepared this way [43]. For example, compounds (26)and (28) can be synthesized from (27) and (29), respectively.Ph Ph Cl(29)(28) (30) (31)9PhPhPh0Ph(34)(33) (35)R1(32)PhNH2A well studied reaction of benzyne is the Diels-Alder reaction inwhich benzyne acts as a dienophile. The benzofuran (30), for example,traps benzyne effectively to give 7-oxanorbornadienes such as (31).Pyrroles also react with benzynes, but the products undergo furtherreactions to form j3-naphthylamines (32) [44]. Tetracyclone (33) is alsofrequently used to trap benzynes and the adducts generally split offcarbon monoxide rapidly to give 1,2,3,4-tetraphenylnaphthalenes (34).Even benzene [45] and naphthalene [46] react readily with benzyne to givebenzo- and dibenzobarrelene, (35) and (36), respectively.Benzyne can also react with an olefin. A remarkable example is thereaction of o-bromofluorobenzene (13) and 3,4-dichlorotetramethylcyclo-butene with lithium amalgam in ether to form (37) [47]. Benzyne can evenadd to more widely separated centers; tetrachlorobenzyne reacts withnorbornadiene to give product (38) together with some [2+2] cycloadditionproduct (39) [48]. Benzyne can add to longer conjugated systems; thus, thethermal decomposition of o-benzenediazonium carboxylate (14) in theabsence of other trapping reagents gives (40) [49].Most recently, reactions of benzyne with fullerenes have beenstudied and a series of compounds of the composition C60 4- (C611 4)n (n= 1 , 2 ,3, 4) were identified by using mass spectroscopy [50]. The monoaddition10Me CI(36) Cl -(38) ClCl(39)^(40)product was isolated by using chromatography and structurallycharacterized by 1 H and 1 3C NMR spectroscopy [50].1.2 Transition Metal Complexes of Benzyne1.2.1 IntroductionDuring the development of organometallic chemistry, especially thatof the transition metals, the ability of metal containing moieties to stabilizehighly reactive organic fragments such as carbene, carbyne, and cyclo-butadiene, on one hand, and to activate stable molecules towards selectiveattack, on the other, have been well established and extensively studied.For example, cyclobutadiene is too reactive to be isolated, but coordinationto a transition metal fragment stabilizes this molecule. The first complex ofunsubstituted cyclobutadiene to be isolated was (rr4 -C4H4)Fe(C0)3 (41), pre-11CIEt3NCI( 1.2 )CqA ,CO CO2NaCo(CO)4 12+hv( 1.3 )(CO)2(42)C I+ Fe2 (CO) 9CI L J(CO)3(41)pared in 1965 as in Equation (1.1) [51]. Cyclobutadiene(cyclopentadienyl)cobalt (42) was later prepared as in Equations (1.2) and (1.3) [52,53]. Themost interesting aspect of these compounds is that the cyclobutadiene canbe liberated and trapped with various organic substrates. Oxidation of (11 4 -C4H4)Fe(C0)3 (41) with CO+ generates transient, free cyclobutadiene whichreacts with alkynes to give Dewar-benzene derivatives, while its treatmentwith p-quinones opens up an elegant route for the synthesis of cubane asshown in Scheme 1-51541The first unsuccessful attempts to form transition metal complexes ofbenzyne made by Wittig and Bickelhaupt [55] involved the treatment of1,2-dilithiobenzene with various transition metal salts. An attempt to12• IFFe(CO)3RCsCRKOH200BBr0 0COOHCe 4+hv^0Scheme 1-5 Synthesis of cubane by using (r14 -C4H4)Fe(C0)3 (41) as asource of free cyclobutadiene.prepare Pt(PPh3)2(C6H4) by treating 1,2-dilithiobenzene with cis-PtC12(PPh3)2 was also unsuccessful [561 as were other early efforts to trapbenzyne, generated from suitable precursors, by zero valent platinumcomplexes. Thermal decomposition of 1,2-benzenediazonium carboxylate(14) or benzo-1,2,3-thiadiazole-S,S-dioxide (17) in the presence ofPt(PPh3)2(C2H4) or Pt(PPh3)4, Scheme 1-6, are two examples. The metalla-cyclic platinum(II) complexes (43) and (44) are the final products [57-591.These are resistant to CO2 or SO2 elimination to give a benzyne complex.UV irradiation of (45) does generate free benzyne which can be trappedwith furan or tetracyclone [57,591. Free benzyne also inserts into theacetylide-metal bond of the nickel(II) complex (46) as in Equation (1.4)[601.13COO" Pt (Pr! 3) 2l‘d2r14/or Pt(PPh3)40 130°Cipt (PPh3)2NONN9C'Opt (PPh3)2citC(17)5;0 12Pt(PPh 3)2(C2H4)N/ ^or Pt(PPh3)402S'Pt(PPh3/2 Et0HNN^70°C0pt (PP h3)2NON(45)(1.4)PEt 3—CCICC12PEt3ScPh(14)^ (43)0 ,/130°CPC(PPh3)2(44 )Scheme 1-6 Reaction of benzyne precursors with Pt(0) complexes [27].PEt3Ph —C NEC NiIPEt3(46)Reaction of Ni(CO)4 with 1,2-diiodobenzene was reported to give abenzyne complex [61], but it was later shown to be a polymeric nickel(IV)complex (47) [62].The first indication of a benzyne transition metal complex was thereactivity change associated with the presence of silver ion observed forthe cycloaddition of benzyne to benzene (Scheme 1-7) [63]. The normal14(48)C6H6trace trace—Ag+1,4-cycloaddition to give benzobarrelene (35) is suppressed and the mainproducts become benzocyclooctatetraene and biphenyl. A silver-benzynecomplex (48) is thought to be involved. Similar effects are observed inother cycloadditions of benzyne [64-66]. C6H6+(35)major(14) (22)Ag+(24)Scheme 1-7 Influence of Ag+ on the cycloaddition of benzyne to benzene.In the course of studying the thermal substitution reactions of PPh3with 0s3(C0)12 in 1972, Bradford, Nyholm and coworkers isolated andcharacterized by X-ray crystallography the first three benzyne complexes(49), (50), and (51) [67-69]. Since then, many transition metal stabilizedbenzyne complexes have been isolated, both with early and late transitionmetals. Though the largest number of these complexes contain three metal15(co)20%Ph2P/Os(C0)3Os•--PPh2(CO)2Ph2P\(CO)2Os ^Os(C0)3H Os" PPh 2(CO)2(51)atoms like Ru3 and 0s3, complexes in which benzyne is stabilized by one,two, four, and five metal centers are known.(49)(C0)20s-,7.7,Os Os(C0)3(PPh3) /..-PPh2H--(CO)2(50)1.2.2 Mononuclear Metal Complexes of BenzyneTwo limiting modes of coordination of benzyne, (52a) and (52b), to ametal center are possible. The contributions from each depend on themetal center and its ligands.M-1(52a) (52b)1.2.2.1 Complexes of early transition metals and actinoid elementsBenzyne complexes are generally implicated as reactive inter-mediates in the thermal decomposition of perphenyl derivatives of theearly transition metals, and of uranium and thorium. A benzyne-chromiumcomplex is probably involved in the hydrolytic a- to 11 6 -rearrangement ofCr(C6H5)3(THF)3 to Cr(C6H6)2+ [70]. Heating Cp2TiPh2 (53) gives mainlybenzene with almost no biphenyl formation. The benzene is formed byelimination of one phenyl group and a hydrogen atom from the ortho-16SeCp TiRCECR'R=R'=Ph;R' R=SiMe 3 , R'=Ph;R=R'=Me, Ph, CF3[ forCp2Ti(m- or p-C61-14Me)2]Cp211 (C6H5)2 -C6H6(53)[Cp2Ti-I(54)Se 5 _^Ti• •01.02 'A(58)(57)position of the other phenyl group [71-73]. A benzyne intermediate suchas (54) is implied which can be trapped with alkynes [74-76], carbondioxide [77] or selenium [78], to give the expected titanacycles (55)-(57) asshown in Scheme 1-8. Compound (54) is probably also formed whenCp2TiC12 is treated with 1-bromo-2-fluorobenzene (13) and magnesiumbecause in the presence of diphenyl-acetylene the titanacycle (55)(R-R'-Ph) was isolated [79].Scheme 1-8 Generation and trapping of [Cp2Ti(C6H4)] (54).Heating CP2TiPh2 (53) or its 3- or 4-tolyl analogues in benzene orether at 80-130 .0 under nitrogen (100 atm) affords small amounts ofaniline or the appropriate toluidine in addition to the main productammonia [80]. Reaction of Cp2TiC12 with 1-bromo-2-fluorobenzene (13)and magnesium under N2 (100 atm) also gives aniline. A nitrogen insertionproduct (58) is believed to derive from (54) and N2. The aromatic aminesare not formed in the corresponding zirconium systems [80].17CpgCp2Zr(m-C6H4Me) 2Cp2Zr(p-C6I-14Me)2[Zirconium complexes Cp2Zr(ary1)2 on heating in aromatic solventsundergo aryl group exchange with the solvent (Scheme 1-9) [81, 82]. Thesereactions suggest a 16 electron aryne-metal intermediate (e.g. (59)).Cp2Zr(p-C61-14Me)(C6H5)C 6H6 CP2Zr(rn -C6H4 Me ) w %, f(59)^ (60)Scheme 1-9 Aryl group exchange in Cp2Zr(ary1)2.Typical reactions of [Cp2Zr(C6H4)] (60) are shown in Scheme 1-10.Ethylene inserts to give the zirconaindan (61) [83], and cis- and trans-stilbene insert specifically to give (62) and (63) respectively [84]. Cyanidesinsert to give azazirconacyclopentenes (68) [85]. The oxophilicity of theCp2Zr unit of (60) is clearly seen from its reaction with W(C0)6 to give (69)[86].Complex (60) can be trapped as a stable trimethyiphosphine adduct(70) whose structure was determined by X-ray crystallography [87]. Readydisplacement of PMe3 in (70) provides a' convenient alternative source of(60). Some insertion reactions of (70) and its methanolysis to give (71) areshown in Scheme 1-11The zirconaindan complex (64) obtained from (60) and 1-hexeneundergoes olefin exchange on heating with norbornene to give a newzirconaindan complex (65) (Scheme 1-12). This implies that benzynecomplexes (66) and (67) are in equilibrium with (64) and (65) respectively[831.18Se t)/,Se• Cp2Zr\seCp2Zr,PMe3(70)Cp2Zr\o W(CO)5(69)^ (68) (63)N^ ptii^PhCp2Zr—)(60)RCNCp2ZrCP2Zr(C6H5)2A/C6H 680°C^C2H4Cp2Zr(61)Ph "r=\PhPhN=_-\PhCp2ZrPMe3EtCp2ZrCp2Zr.,.pme3(70)EtCECEt^Me2C0/PhMe0H Cp2Zr,,ome(71)MetBuCNScheme 1-10 Reactions of [Cp2Zr(C6H4)] (60) [27].Scheme 1-11 Reactions of Cp2Zr(C6H4)(PMe3) (70).19(65)Cp2Zr ^I ^ Cp2Zr(67)Cp2Zr(66)Scheme 1 - 12 Olefin exchange in zirconaindan complexes.A more general route to aryne-zirconocene complexes involves thetreatment of Cp2ZrCl(Me) with an aryllithium [88]. The resulting complexCp2Zr(ary1)(Me) readily loses methane on heating to give the transientaryne complex (72) which can be trapped with cyanides (Scheme 1-13) orethylene (Scheme 1-14) [88]. The zirconacycles can be converted intoorganic products such as aromatic ketones and 2-iodo-phenylketones,isothiazoles (Scheme 1-13) and dihydrocyclobutabenzenes (Scheme 1-14).The high regiospecificity in the reactions in Scheme 1-13 is presumablydue to steric hindrance of the substituents X [88].Phenyl derivatives of bis(pentamethylcyclopentadienyOzirconium[89,90], -uranium [90], and -thorium [91] also undergo phenyl groupexchange with aromatic solvents, and the intermediate benzyne complexescan be trapped with ethylene or diphenylacetylene. A solution of Cp2*ZrD(Ph) in C6D6 incorporates deuterium in both the phenyl ring and in the Cp*methyl groups at room temperature; these processes probably proceed viathe benzyne complex (73) (Scheme 1-15). When either Cp2*ZrPh2 orCp2*ZrH(Ph) is heated in benzene, the cyclometalated complex (74) isformed by hydrogen transfer from a Cp* methyl group to the coordinatedbenzyne [89,90]. Similar processes occur on heating complexes Zr(i5-20MeCNI 1. Cp2ZrCIMe2.(72)COMe(a)COMBX=OMe, 98:2X=Me, 100:0Scheme 1-13 Synthesis and reactions of [Cpgr(aryne)] (72) [27].(a) Only one isomer observed for X-OMe, Me. ZrCp2 C2H4 "BuLi(72) (a) (a)Scheme 1-14 Synthesis of dihydrocyclobutabenzenes from (72).(a) Mixture of regioisomers.21PhZr/Ph 120°C_ _-■Ph"C6H6Ph -HD -HD+HD +HD-HD+HDScheme 1-15 Hydrogen/deuterium exchange in Cp2*Zr(D)(Ph).(1.5)C5H4CMe2Ph)2Ph2 and Zr(rL5-C5H4CMe3)2Ph2; the former undergoes aphenyl C-H bond activation of the CMe2Ph substituent preferentially(Equation 1.5) [921.Scheme 1-16 shows the reaction of Ph3P=CH2 with [Cp2Zr(C6H4)1 (60)22(76) (77)to give the phenylzirconium(IV) complex (75), probably via anintermediate zirconium(II) complex. A hydrogen atom is transferred fromthe ylide to the coordinated benzyne. The 4-methylbenzyne complex (59)reacts with Ph3P-CH2 similarly to give a mixture of 3- and 4-tolylderivatives 1931. The titanium analogue of (59) behaves similarly, but herea competing reaction also occurs in which PPh3 is eliminated and CH2inserts into the titanium-aryne bond to give (76) and (77) 1941CP2Zr(C6H5)2C6H680°C Cp2Zr—I(60)Phi-C142 [Cp2Zr <\CH+PPR3Cp2Zr IIPPh 3Scheme 1-16 Reaction of [CP2Zr(C6H4)] (60) with Ph3P-CH2.The elimination of benzene or an alkane from appropriate precursorcomplexes has given benzyne complexes of Nb, Ta, Mo, W, and Re. Forexample, Cp*M(Ph)Me3 (M-Ta, Nb) lose methane on heating to givebenzyne complexes (78) and (79) [951. Complex (78) was the first23mononuclear benzyne complex to be structurally characterized [95,96].The reaction of Cp2 *TaC12 with PhLi (1:2 molar ratio) also gives benzynecomplex [Cp2 sTa(C6H4)H1 (81) directly. This compound was shown to be inequilibrium with the a-phenyl complex Cp2 *Ta(C6H5) [971. The reaction ofPh2Zn with Cp`Ta(CH2CMe3)C13 (Equation 1.6) gives the benzyne complex(80) without the presumed intermediate being detected 195].Cp*Ta(CH2CMe3)C6 Ph2Zn [ Cp*Ta(CH2CMe3)(Ph)C12] -CMe4 (1.6)A series of benzyne complexes of general formula IlLi(Et2O)]nIM(C6H4)2(C6H5)4] are formed from MC15 (M-Ta, Nb, W, and Mo) and PhLior arylLi in ether [98-102]. Hexaphenylmetalates of the general formulaILi(Et20)ln[M(C6H5)6] are likely precursors to the bis(benzyne) complexes[98, 99]. Table 1-1 summarizes the compounds described to date with theformal oxidation states and electron configurations of the metal atoms.Benzyne is regarded as a neutral or a dianionic ligand. The productsisolated from these reactions are very sensitive to slight changes inexperimental conditions and to the reagents used.Complexes with the empirical formulae (88) and (89) have beenstructurally characterized 1103]. The niobium center in (88) has anapproximately trigonal bipyramidal geometry with both q 2 -benzyneligands in equatorial positions. The tantalum center in (89) is coordinated24Table 1-1. Anionic bis(aryne) complexes isolated from reactions of earlytransition metal pentahalides with aryllithium reagents [27].Reactants Productsa Oxidation state, doC6H4 neutral (dianion)ReferencesNbBr5/PhLi/Et20 (82)b Nb(0),d5 (Nb(IV),d 1 ) 98,100TaBr5/PhLi/Et20 (83) Ta(0),d5 (Ta(IV),d 1 ) 97b,100TaBr5/PhLi/Et20 (84)c Ta(I),d 4 (Ta(V),d 0 ) 97b,100MoC15/PhLi/Et20 (85) Mo(0),d 6 (Mo(IV),d 2 ) 97bWBr5/PhLi/Et20 (86) W(0),d 6 (W(IV),d 2 ) 98,100WBr5/4-tolylLi/Et20 (87) W(0),d 6 (W(IV),d 2 ) 101NbC15/PhLi/THF (88)d Nb(-I),d 6 (Nb(III),d 2 ) 102TaC15/PhLi/THF (89)e Ta(I),d 4 (Ta(V),d 0 ) 102a. [Li(Et20)]4[Nb(C6H4)2(C6H5)4] (82) [Li(Et20)]4[Ta(C6H4)2(C6H5)41 (83)[Li(Et20)i3iTa(C6114)2(C6H5 )4] (84)^[Li(Et20)14[Mo(C6H4)2(C6H5 )4] (85)fLi(Et20)14[W(C6H4)2(C6H5)41(86) [Li(Et20)]4[W(C6H3Me)2(p-C6H4Me)41(87)^[Li(THF)14[Nb(C6H4)2(C6H5)31[C6H5Li(THF)]•0.5THF•0.5C6H14 (88)[Li(THF)]2fLi4C12(THF)101[Ta(C6H4)2(C6H5)41 (89) b. Thermally unstable.c. Intermediate in the synthesis of (83). d. Contains five-coordinated Nb.e. Contains six-coordinated Ta.in approximately octahedral geometry with two n 2 -benzyne ligands in a cisarrangement. If C6H4 is regarded as dianionic, the coordination geometriesof (88) and (89) are approximately pentagonal bipyramidal and squareanti-prismatic, respectively. These anions are thought to be stabilized by25extensive secondary interactions between solvated lithium ions and carbonatoms of the C6H4 and C6H5 moieties.The benzyne tantalum complex (91) is in equilibrium with thephenyl-substituted metallaspiro complex (90) at 120°C [104, 105]. Ahydrogen atom transfers reversibly between the phenyl group and the Ta-CH2 group (Equation 1.7).(1.7)(88) (89) (90) (91)The aryne complex Mari 2 -3-C6H3Me)(2-McC6H4)2(PMe2Ph)2 (92) isformed by the interaction of PMe2Ph with Mo(2-MeC6H4)4, and theanalogous complex W(n 2 -3,6-C6H2Me2)(2,5-Me2C6H3)2(PMe3)2 ( 9 3) isobtained similarly from PMe3 and W(2,5-Me2C6H3)4 [106]. Both structureshave been determined and they have approximate trigonal bipyramidalgeometries around the metal center. Similar reactions of Re(2 - MeC6H4)4with PMe3 or PMe2Ph afford paramagnetic 3-methylbenzyne complexes(94) [107, 108]. They undergo facile reversible oxidation to thediamagnetic cations (95) (Equation 1.8). X-ray crystallographic analyses of(94) (L-PMe2Ph) and (95) (L-PMe3, 15 - salt) show that both haveapproximately trigonal bipyramidal structures. Unlike some other benzynecomplexes, these two compounds are remarkably inert towards a variety26(94)1.8)[04=FeCp2+, CO2(C0)8, Ag[CF3SO3],CF3SO3H; [Red]=Li[13Et3H], Me3SiCH 2MgCl.[Ox][Red]of substrates such as olefins, acetylenes, acetonitrile, and acetone.No benzyne complexes of hafnium, vanadium, chromium, manganeseand the lanthanides have been observed or implicated as reactionintermediates. Also, the chemistry of benzyne complexes has been largelydeveloped from titanium and zirconium complexes, and relatively littleattention has been paid to the complexes of niobium, tantalum,molybdenum, and tungsten.1.2.2.2 Complexes of Late Transition MetalsThe possible involvement of a silver-benzyne complex in thecycloaddition of benzyne to benzene has been mentioned (Section 1.2.1),but no effort has been made to stabilize or isolate such complexes.Despite early unsuccessful attempts to stabilize benzyne on platinumcenters (Section 1.2.1), the first well characterized mononuclear group 8metal benzyne complex, a nickel(0)-benzyne complex (96), was obtained asshown in Scheme 1-17 and the structure of (96) was determined by X-raycrystallography [109]. Complexes NiL2(C6H4) (1.4-13Cy3, PiPr3) were obtainedsimilarly [27], although the PEt3 complex was assigned a dimericphenylene structure [1101.27(97)1% Na/HgCY2/N .EY2(96)X 2LPPh3,NiPh3r yX,Y=CI,Br,INi(COD)2/bipyNi(COD)(BiPy)ZnNiCl2(PPh3)2 V^ultrasoundCompound (96) or its analogues cannot be prepared by usingprocedures analogous to those used to prepare the zirconocene compoundssince on heating, diphenyl- or methyl(phenyl)nickel(II) complexes undergoreductive elimination rather than hydrogen abstraction. Convenient highyield routes to the (2-halogenphenyl)nickel(II) halide precursors areshown in Scheme 1-18 [27].^Cy2^ Cy2;^13,^1. o-Br2C6H4C - -HI2.1..14. C Ni—II 2. LiCI/^CI^)92 EY2Scheme 1-17 Preparation of Ni(Cy2PCH2CH2PCy2)(C6H4) (96).(BiPy)Ni, yScheme 1-18 Preparation of (2-halogenphenyl)nickel(II) halidecomplexes [27].28PhCH2OH C6 H 6CY2C \/NEY2(96)CY2CP\NI\OCH2PhCY2CY2P\  H Ph(1.9)CY2Mononuclear platinum-benzyne complexes PtL2(C6H4) (2L-2PEt3,2PCy3, 2PiPr3, Cy2PCH2CH2PCY2) have been prepared similarly [27].Tertiary phosphines in M(PiPr3)2(C6H4)^Pt) can be replaced by lessbulky phosphines, thus M(PMe3)2(C6H4)^Pt) and Pt(P 1Pr3)L(C6H4)(L=PMe3, PEt3, PPh3, PMe2Ph, PMePh2) have been characterized [27].These benzyne complexes are very sensitive to water, alcohols, andother protic solvents. For example, the nickel complex (96) reacts rapidlywith primary and secondary alcohols to give alkoxides; these are unstableat room temperature and form the nickel(0) complexes of aldehyde orketone with elimination of benzene (Equation 1.9) [109]. The benzyne-nickel bond in (96) is also attacked by other electrophiles such as iodineand methyl iodide and undergoes insertion with CO2, ethylene, anddimethyl acetylenedicarboxylate to give metallacycles (Scheme 1-19)[10.9]. Whereas acetonitrile inserts into the benzyne-zirconocene complex(60), it is deprotonated by (96). Also in contrast with [Cp2Zr(C6H4)] (60),(96) does not undergo insertion with diphenylacetylene; instead, thebenzyne is displaced to give Ni(Cy2PCH2CH2PCy2)(Ph-CEC-Ph) [109].A very reactive ruthenium benzyne complex (PMe3)4Ru(n 2 -C6H4)(98) has been reported and structually characterized [111]. It is generatedby heating the cis-diphenyl or the cis-methyl (phenyl) precursors. Theruthenium-benzyne bond in (98) reacts with a wide range of substrates29Cy2PC \Ni<H2CNEY2CH3IPh-C-C-PhCOOMeCH3CNY2p\L., 1NigY2(96)CY2P\C I.N .bY2ICY2 Ph>ill42 PhCy2lkC ;N .8112Cy2P\C N .E/Y2PCY2C '/NEY2CO2C2H4ICPY21....... ;NibY2Scheme 1-19 Reactions of Ni(Cy2PCH2CH2PCY2)(C6H4) (96) [27].that are typically inert toward late transition metal-carbon bonds,including those in benzyne complexes [109, 112]. The reactions aresummarized in Scheme 1-20. The reaction with C6D6 parallels that in thezirconium system (Scheme 1-9), but with PhCH3 simple exchange does nottake place, instead a methyl C-H is also activated to give the 4-memberedmetallacycle. Benzaldehyde inserts into the ruthenium-benzyne bond justas acetone inserts into the zirconium benzyne trimethylphosphine adduct(70), however, acetone undergoes C-C bond cleavage in reaction with (98)to form the unusual compound (99). Interestingly, the reaction ofacetophenone with (98) also gives (99) presumably by way of the phenylenolate complex (100).There are no known mononuclear benzyne complexes of iron,osmium, cobalt, rhodium, iridium, copper, gold, zinc, cadmium, mercury,30cis-L4Ru(CI)(Me)L=PMe3Ll- p.) C),eL.- N Ph PhL(100)LL^°I.Iu1_^ILCH2(99)FimilBrkk.^LL igiu R 1V. I Th2LR i =R2=PhFl 1 =Ph,R2=MeMeCOPhPhCHOLL-^1^Ph■L' Iu NHArLAHBOLL RIu SOHLand most remarkably palladium. The rich chemistry of the rutheniumbenzyne complex (98) and the zirconium benzyne complexes (60) and (70)are particularly accessible and general applications of these benzynecomplexes in synthesis may be expected.Scheme 1-20 Preparation and reactions of (PMe3)4Ru(n 2 -C6H4) (99).1.2.2.3 Structure and Bonding of Benzyne in Mononuclear Metal ComplexesTable 1-2 compares the benzyne C-C bond lengths determined by X-ray crystallography in various complexes with those in free benzyne as3 1obtained by an ab -initio calculation [32]. In all cases the "acetylenic" bond(C1-C2) is lengthened on coordination; the remaining C-C bonds are ofabout the same length as those in free benzyne. The greatest deviation isfound in complex (92) where C2-C3 (1.52±0.06 A) and C6-C1 (1.60±0.06 A)are much longer and C5-C6 (1.26±0.06 A) much shorter than thecorresponding lengths in free benzyne.Table 1-2. Comparison of C-C bond lengths in metal benzyne complexeswith those in free benzynea [27].C6H4b (70)^(88) (89)^(78)^(92)C (9 3)C (94)C (95)C^(98) (96)C1-C2 1.2401.364(8)1.419(7) 1.384(8)1.364(5)1.276(16)1.410(7) 1.402(8)1.431(33) 1.34(1)1.39(2) 1.355(3) 1.332(6)C2-C3 1.393 1.389(8) 1.410(5) 1.522(19) 1.410(32) 1.43(1) 1.39(2) 1.372(3) 1.386(6)C3-C4 1.402 1.383(9) 1.362(2) 1.417(18) 1.357(35) 1.38(1) 1.39(2) 1.411(4) 1.383(7)1.388(8) 1.380(9)C4-05 1.421 1.380(9)^- -^1.403(6) 1.443(18) 1.470(43) 1.41(1) 1.44(2) 1.363(4) 1.390(8)1.416(7)d 1.404(9) dC5-C6 1.402 1.377(9) 1.375(6) 1.261(18) 1.478(39) 1.37(1) 1.36(2) 1.398(4) 1.383(7)C6-C1 1.393 1.406(8) 1.408(6) 1.595(19) 1.441(35) 1.41(1) 1.36(2) 1.382(3) 1.389(6)a. Carbon atoms numbered as in Figure 1-1. b. Calculated values from ref.32. c. The carbon where methyl attaches is numbered 3. d. C4-05 is theshortest bond.Benzyne behaves as a two electron donor in (70), (96) and (98) andthese are saturated complexes. The nickel complex (96) is similar to other16 electron ML2(alkyne) (M-Ni, Pt) complexes. Though the Cl-C2 bond32M(101)^(102) (103) (104) (105)length of 1.322(6) A is greater than the value of 1.29 A typical of mostML2(alkyne) complexes, the lengthening on coordination relative to thefree ligand is about the same [27]. All the other C-C bonds in (70) and (96)are almost equal and show no variation indicating delocalization of the itelectrons. Thus a reasonable representation would be structure (101). Incomplex (98), the C-C bonds do show alternation indicating slightlocalization of the aromatic it electrons though the average value 1.385 Adoes not differ from those of (70) and (96). An appropriate representationis . structure (102).All the other complexes listed in Table 1-2 are unsaturatedelectronically, and the benzyne most probably donates two to fourelectrons. The bond lengths of the rhenium complexes (94) and (95) do notshow clear alternation, and the authors suggest that these structures bebest described as a rhenacyclopropene type with a delocalized aromaticbenzyne ring (structure (103)).The molybdenum and tungsten benzyne complexes (92) and (93)seem to have relatively large deviations in the bond lengths, and structure(104) is possibly the best representation of the benzyne bonding.The niobium and tantalum complexes (88) and (89) have shorter M-C(aryne) (by 0,07-0.14 A) bonds than the other complexes in Table 1-2, andthese bonds are presumably stronger than the 6-M-C (aryl) bonds. The Cl-C2 (aryne) distances in (88) and (89) (average 1.414(8) and 1.393(8) Arespectively) are slightly longer than those in (70) and (78). The remaining33C-C distances in (88) and (89) show very small, if any, variation and thebonding can be represented by structure (103).Finally the tantalum complex (78) is highly electron-deficient. TheCl-C2 distance is similar to those in (70), (89), (94) and (98), but theremaining C-C distances show a similar long-short alternation as found in(92). Also, the benzyne ligand in (78) is oriented perpendicular to theplane of the Cp* ring, whereas in the ethylene complex Cp*TaMe2(C2H4) theolefin is parellel to this ring. These observations led to the suggestion thatboth sets of orthogonal benzyne n-orbitals are involved in bonding to themetal [94,95]. Thus benzyne bonding in (78) could be represented as instructure (105).1.2.3 Metal Cluster Complexes of BenzyneBy far the largest number of known benzyne complexes are thosebased on triruthenium and triosmium carbonyl metal frameworks [27,1131. No benzyne cluster complexes of other metals have been described.Much attention has been paid to the structures and fluxional behaviour ofthese benzyne complexes; relatively little attention has been paid to theirchemistry [1141.1.2.3.1 Ruthenium Cluster Complexes of BenzyneThe first three ruthenium cluster benzyne complexes Ru3(p.3-C6H3R')(PR2)2(C0)7 (R'-'H, R=C6H5, (106a); R'=Me, R=3-MeC6H4, (106e); R'=Me, R=4-MeC6H4, (106f)) were isolated following the pyrolysis of Ru3(C0)9(PR3)3(R-Ph, 3-MeC6H4, 4-MeC6H4) in refluxing decalin or mesitylene, and werecharacterized on the basis of analytical and spectroscopic data [115]. The34crystal structure of (106a) was determined later [116] revealing that itbelongs to a structural series known previously for osmium (e.g. structure(49)). Complex (106a) was also obtained from the pyrolysis of Ru3(CO)10(PPh3)2 and Ru3(C0)11(PPh3) [117, 118]. The latter starting material alsoafforded a tetra-nuclear benzyne complex Ru4(C0)10(11-00)(114 -C6H4)(114 -PPh) (107a) and a penta-nuclear benzyne complex Ru5(C 0 )13(µ5 -C6H4)(114 -PPh) (108a), the structures of both have been determined [117, 118].Complexes (106e) and (106f) were also obtained from the pyrolysis ofRu3(CO)i i(PR3) (R=3-MeC6H4, 4-MeC6H4) which in addition afforded thetetra-nuclear benzyne complexes Ru4(C0)10(11-00)(44-C6H3W)(114-PR) (R'=Me,R=3-MeC6H4, (107d); R'=Ivie, R-4-MeC6H4, (107e)) [118]. Pyrolysis ofRu3(CO)i 1(Ph2PCH2NPh2) afforded the tetra-nuclear benzyne complexRu4(C0 )10(g -00)(14 - C6H4)(1.14 -PCH2NPh2) (107b) and its structure wasdetermined [117, 118]. Pyrolysis of Ru3(CO)1 I(AsPh3) afforded both thetetra-nuclear Ru4(C0)10(g -00)(g4 -C6114)(14 -AsPh) (107f) and the penta-nuclear benzyne complexes Ru5(C0)13(115 -C6H4)(114 -AsPh) (108b), but noanalogue of (106a) [118]. Pyrolysis of Ru3(CO)1 i(PPh2Me) gave a hexa-nuclear bis(benzyne) complex Ru6(C0)12(g4 -PMe)2(13 -C6114)2 (109) whosestructure was determined [118]. An attempt to trap ferrocyne by pyrolysisof Ru3(C0)10(PFcPh2)2 was unsuccessful, instead the benzyne complex(106b) was obtained in good yield [119]. Further effort in this respectinvolving Ru3(C0)10[FOPPh2)2] as a potential source of ferrocyne led to thecharacterization of a number of products, and while no ferrocynederivatives were isolated, two benzyne complexes (106c) and (107c) wereobtained and characterized by X-ray diffraction studies 1120]. A similarattempt to trap (benzyne)chromium tricarbonyl via pyrolysis ofRu3(C0)11(PPh2[C6H5Cr(C0)3]) led to the complex (106d)[121].35(CO)3RU1(C0)3RU ■^ • I..4%%%,...•%% . .t.000.eER '-, Ru (C0)2, \/COu (C0)2Remarkably similar structures were found in the series (106a)-(106d). Table 1-3 summarizes some important bonding parameters forthese complexes and the numbering scheme is shown in Figure 1.2. In thestructures, Ru(1)-Ru(2) and Ru(2)-Ru(3) are asymmetrically bridged bythe phosphido groups PA and PB, respectively. One of the CO groups onRu(1) is semibridging with Ru(3); all other CO groups are normal terminalcarbonyls. Ru(1)-Ru(2) is significantly longer than the other two Ru-Rubonds with Ru(2)-Ru(3) being slightly longer than Ru(1)-Ru(3). PA liesabove the Ru3 plane on the same side as the benzyne moiety, while PB issituated below the Ru3 plane.d, PR2=PPh[(C6H5)Cr(C0)3],PPh[(C6H5)Cr(C0)3l,R'=H(C0)2 Ru^Ru (C0)3^\ I^R2P^Ru---PR2(CO)2a, PR2=PPh 2 , PPh2 , R'=Hb, PP2=PFcPh, PFcPh,R'=Hc, PR2=PFcPh, PPh2 ,R'=He, PR2=P(m-MeC 6 H4 )2 , P(m-MeC6H 4)2 , R'=Mef, PR2=P(P -MeC6H4)2 , P(P-MeC6H4)2 , R'=Me(106)!a, ER=PPh, R'=Hb, ER=PCH2NPh2 , R'=Hc, ER=PFc, R'=Hd, ER=P(m-MeC6H4), R'=Mee, ER=P(p-MeC6H4), R'=Mef, ER=AsPh, R'=H(107)3 6Ru(C0)3(CO)2(C0)3Ru-(C0)3Ru^ Ru(CO)2XIEVa, ER=PPhb, ER=AsPhMeP(108)^ M= Ru(CO)2(109)^3^1(C0)2Ru ^R (C0)3^\^IR2P B^PAR2CO)2Figure 1.2 Numbering of complexes (106).Though complex (106a) has no possible geometrical isomers,complexes (106b), (106c), and (106d) have at least one other possibleisomer ( e.g. with the bulky ferrocenyl or (phenyl)chromium tricarbonylgroup on PA lying on the other side of the Ru3 plane. In both (106b) and(106c), the ferrocenyl group on PA points to benzyne side of the Ru3 plane.The (phenyl)chromium tricarbonyl moiety on PA in (106d) has the samearrangement. The ferrocenyl and (phenyl)chromium tricarbonyl groups onPg in (106b) and (106d), respectively point to the opposite side of the Ru3plane. No evidence for the existence of these isomers was reported. In both(106e) and (106f), the methyl group is in the 4-position of the benzyne37Table 1-3. Some important structural parameters for complexes (106)a.(106a)[1161 13(106b)[119]b(106c)112OP(106d)[1211"Ru 1 -Ru2 2.956(1) 2.8983(8) 2.938(1) 2.9227(8)Ru2-Ru3 2.776(1) 2.7748(8) 2.794(1) 2.793(1)Ru3-Rul 2.759(1) 2.7420(8) 2.779(1) 2.7248(8)PA-Rul 2.361(2) 2.380(2) 2.378(2) 2.360(2)PA -Ru2 2.319(2) 2.321(2) 2.314(2) 2.311(2)PB -Ru2 2.334(2) 2.343(2) 2.320(2) 2.340(2)PB -Ru3 2.267(2) 2.270(2) 2.251(2) 2.266(2)C(semi-bridging 2.625(6) 2.670(8) 2.696(8)CO)-Ru3Rul-C-0 164.4(6) 165.3(7) 169.8(9)Rut-C1 2.127(6) 2.123(7) 2.116(8) 2.117(6)Ru2-C2 2.135(6) 2.123(7) 2.138(8) 2.132(6)Ru3-C1 2.303(6) 2.318(6) 2.374(8) 2.327(6)Ru3-C2 2.353(6) 2.360(6) 2.313(8) 2.319(6)C6H4 toRu 3 c 65.2 64.0(2) 61.5(2)a. All bond lengths in (A) and angles in (°). b. These are correspondingreferences. c. The angle refers to the dihedral angle between the benzyneand Ru3 planes.ligand. This is attributed to reversible hydrogen transfer between thebenzyne moiety and the metal cluster [1391, a process that also occurs in0s3 complexes 1128].Some degree of bond localization is found in the benzyne ligand. Thebond lengths and angles for the benzyne moiety in (106b) are shown inFigure 1.3 as an example. The C(3)-C(4) and C(5)-C(6) bonds are somewhat38benzyne fragment in (106b) indicate that a 180 rotation process is lessfacile than in related 0s3 systems [119].5 1.398(12  4.)1210(7)^1.379(1 1)^121.0(7)6^21.1(7) 120.5(7)1.410(9)^118.8(5)118.6(6)1.417(9).350(12)3.438(10)Figure 1.3 Bond lengths (A) and angles (°) of benzyne in (106b).The structures (107a)-(107c) contain a square Ru4 unit capped onone face asymmetrically by a g4-phosphinidene ligand, and on the other bya g4-benzyne moiety that in this case acts as a six-electron donor to theRu4 plane. The important bonding parameters are tabulated in Table 1-4and the numbering scheme is shown in Figure 1.4. Ru(1)-Ru(2) lies close tothe C6 plane and show Ru-C a bond distances that are considerably shorterthan the 7r-bonded Ru(3)-C and Ru(4)-C distances. The 71 2 -interaction ofC(2)-C(3) and C(6)-C(1) with Ru(3) and Ru(4), respectively, are ratherasymmetric. The flexibility of this bonding mode is reflected in the varyingangle between the Ru4 and C6 planes. Some bond localization within thebenzyne moieties is present with (107b) as an example (Figure 1.5), butthe alternation trend is opposite to that shown in Figure 1.3 for (106b),that is, the C(1)-C(2) bond is longer than C(3)-C(4) and C(5)-C(6) which arelonger than C(1)-C(6) and C(2)-C(3). The C(4)-C(5) bond is the shortest.39Table 1-4. Important bonding parameters for complexes (107).a107ab[117, 1181C107b[117, 1181C107c(120]cRu 1-Ru2 2.943(1) (2.932(1)) 2.921(1) 2.993(4)Ru2-Ru3 2.896(1) (2.918(1)) 2.927(1) 2.893(3)Ru3-Ru4 2.791(1) (2.805(1)) 2.816(1) 2.841(4)Rul-Ru4 2.891(1) (2.910(2)) 2.875(1) 2.879(2)Rul-P 2.352(3) (2.344(3)) 2.359(1) 2.351(7)Ru2-P 2.353(3) (2.354(4)) 2.356(1) 2.348(7)Ru3-P 2.425(3) (2.444(3)) 2.423(1) 2.478(7)Ru4-P 2.446(3) (2.432(3)) 2.469(1) 2.495(7)Rut-Cl 2.108(10) (2.100(11)) 2.115(4) 2.10(3)Ru2-C2 2.1 10(10) (2.122(10)) 2.117(3) 2.10(2)Ru3-C2 2.294(9) (2.309(12)) 2.301(4) 2.32(3)Ru3-C3 2.656(11) (2.583(12)) 2.634(4) 2.61(3)Ru4-C1 2.299(10) (2.317(13)) 2.292(4) 2.30(3)Ru4-C6 2.689(11) (2.619(14)) 2.592(4)C6H4d to 54.7 (49.0) 50.9Ru4a. All bond lengths in ( A ) and angles in (°). b. Two crystallographically distinctmolecules are found. Data in brackets are for the second molecule. c. These are thecorresponding references. d. The angle refers to the dihedral angle between thebenzyne and Ru4 planes.4,Ru (C0)2COC(C0)3Ru ^„ u (C0)22^.`,F).: 3RFigure 1.4 Numbering of complexes (107).40^1.427(6)^1.407(6)6 3^1.391(5)^.380(9).447(5)5^4Ru 1^Ru2Figure 1.5 Bond lengths (A) of benzyne in complex (107c).The Ru5 complex (108a) may be envisaged as a derivative of (107a)formed by replacing the bridging CO with a Ru(C0)3 moiety that is r1 2 -bonded to the remaining carbon atoms C(4) and C(5) in the C6 ring. Thenumbering is shown with the structure (108a). The gephosphinidene capsthe square Ru4 unit symmetrically (P-Ru(n) lengths 2.379(1), 2.386(2),2.378(2), 2.381(2) A). The Ru(1)-Ru(2) (2.902(1) A), Ru(2)-Ru(3) (2.905(1)A) and Ru(4)-Ru(1) (2.897(1) A) distances are the same and the longest,while Ru(3)-Ru(5) (2.769(1) A) and Ru(4)-Ru(5) (2.783(1) A) are theshortest. The Ru(3)-Ru(4)-Ru(5) unit is similar to the 0s3 unit in0s3(C0)9(C6H6) [122]. As in (107a), Ru(1) and Ru(2) are almost coplanarwith the benzyne ring and the Ru(1)-C(1) (2.097(6) A) and Ru(2)-C(2)(2.116(6) A) bonds are as expected. The Ru-C bonds involving the 11 2-bound carbon atoms are longer. Thus, Ru(3)-C(2) (2.334(5) A) and Ru(4)-C(1) (2.251(6) A) are longer, Ru(3)-C(3) (2.391(5) A), Ru(4) -C(6) (2.391(6)A), Ru(5) -C(4) (2.398(7) A) and Ru(5) -C(5) (2.427(6) A) are the longest.The bond length alternation in the benzyne ring is similar to that in (107b)(Figure 1.5). An interesting feature of the structure of (108a) is that thefive ruthenium atoms mimic a step-site on a metal (111) surface, thus41Ru(3)Ru(4)Ru(5) would be in one terrace and Ru(1)Ru(2) would be stepatoms in the first row of the next terrace. It is attractive to envisage thatthe approach of a benzene molecule to a metal (111) surface in whichthere are exposed, low-coordinate, step atoms would result in theactivation of two ortho-C-H bonds, to generate benzyne chemisorbed as in(108a) [123].The Ru6 complex (109) may be viewed as having a slipped trigonalprismatic Ru6 core in which two of the quadrilateral faces of the prism arebridged by the µ4-PPh groups, while the third has a diagonal Ru-Ru bond(Ru(11)-Ru(14)). The Ru atoms each carry two terminal CO groups. Thetriangular faces of the Ru6 prism are each capped by a g3-benzyne moiety.The Ru(13)-Ru(15) bond is the longest at 3.143(1) A followed by thediagonal Ru(11)-Ru(14) bond of 2.991(1) A. In each of the two triangularfaces, one Ru-Ru bond (Ru(11)-Ru(13) 2.915(1) A, Ru(14)4-Ru(15) 2.916(1)A) is longer than the other two which are almost equal and are theshortest (Ru(11)-Ru(12) 2.740(1), Ru(12)-Ru(13) 2.739(1) A; Ru(14)-Ru(16) 2.731(1), Ru(15)-Ru(16) 2.748(1) A). Both phosphinidene caps areslightly asymmetric with P-Ru(13) and P-Ru(15) bonds ca. 0.05 A longerthan the others. The benzyne moiety is bonded to the Ru3 face in a fashionsimilar to that found in (106a) except that here both the o (by ca. 0.03 A)and the it (by ca. 0.12 A) bonds are shortened. The C-C bond alternationpattern is also similar to that in (106a), and the electron localization iseven more profound.Some reactions of (106a), (107a) and (108a) with CO have beenstudied [114] and are summarized in Scheme 1-21. Treatment of (106a)with CO at room temperature yields (110) quantitatively and the structureof its PiPr3 derivative was determined. The Ru3 triangle is opened and CO42toluenereflux0Ph^\\/Crill^Ru (CO)3(CO)ainsertion generates a novel orthometalated benzoyl ligand that triplybridges the Rua unit in w-acyl fashion. The µ4-benzyne complex (107a)undergoes cluster fragmentation under CO (50 atm) at 60.0 to give the^(C0)2 R\^Ru (C0)3^CO (1 atm) ^(C0)2RuRu(C0)3^ph 2PPrRu PPh2^hexane reflux^Ph2P .....-.pph2(CO)2 (CO)2(106a) (110)(a3NPh(co)2 CO(CO)flu-^„Au^toluene00reflux(107a)Ph^0(CO)3(C0)4Ru\--^/\c(C0)3Ru-0-0/(112)Iuv^(CD)3 ^/ ZRu(C0)2^RPh(108)(C0)3Ru(CO)fiu-^""u (c0)2\\.Scheme 1-21 Reactions of benzyne complexes (106a), (107a), and (108).u(C0)2(111)dinuclear compound (112) in good yield. The 1.L5-benzyne complex (108)also undergoes cluster fragmentation under CO (50 atm) at 100.0 to giveRu3(C0)12 and (111), but not (112). The structure of (111) and (112) were43( c 801 k: 470‘22 01pS1 (pChO ) 3..,...^2(51)44established by X-ray diffraction studies. In both (110) and (111) one COmolecule has been inserted into the cluster-benzyne moiety. In (112) twoCO molecules have been inserted into the Ru-benzyne a-bonds to form apathaloyl ligand. Under refluxing complexes (110), (111) and (112) reformthe starting complexes (106a) and (107a), respectively.1.2.3.2 Osmium Cluster Complexes of BenzyneThe first three benzyne complexes to be isolated were 0s3 clustercomplexes (49), (50) and (51) which have already been mentioned (Section1.2.1) [67-69]. They were obtained by heating 0s3(CO)12 with PPh3 orrefluxing 0s3(CO)10(PPh3)2 in xylene, and all were structurallycharacterized. The structure of (49) is typical of a range of 0s3 and Ru3complexes. All the three structures are closely related. In (51), thebenzyne moiety is bonded to the ortho position of a phenyl group on aPPh2 moiety that is attached to Os(3). This compound shows a rareexample of C-C coupling.Pyrolysis of 0s3(C0)11(PMe2Ph) produces HOs3(g3-C6H4)(PMe2)(C0)9(114a), similarly 0s3(CO)10(PMe2Ph)2 affords 0s3(µ3-C6H4)(PMe2)2(C0)7(113a), an analogue of (49), H0s3(113 - T1 3- Me2PC6H4C6H3)(PMe2)(C0)8 (115)6 23^1(C0927 Zsp (CO)3Ph 2 P —Os 2 12 (CO)2(49)3Mee P^Os --(C0)21Os(c0)3P Me2Os 2(CO)3and HOs3(g3-C6114)(PMe2)(C0)8(PMe2Ph) (116) [124, 125]. Pyrolysis of 0s3(CO)11(AsMe2Ph) affords HOs3(g3-C6H4)(AsMe2)(C0)9 (114b), and pyrolysisof 0s3(CO)10(AsMe2Ph)2 also affords (114b) in addition to 0s3(g3 - C6 11 4)(AsMe2)2(CO)7 (113b). Complex (113b) was also obtained by heating0s3(CO)12 with 1,2-C6H4(AsMe2)2 [125]. All these complexes werecharacterized by spectroscopic and analytical techniques and the structureof (114b) was confirmed by an X-ray diffraction study [126]. Anothercomplex HOs3(C0)9(C6H4)(PEt2), obtained from the pyrolysis of 0s3(C 0 )11(PEt2Ph), was also mentioned and presumably it has the structure (1 14c)[127].Variable temperature 1 H and 31 P NMR studies of (113) reveal thatthe benzyne moiety is fluxional; a rapid rotation and flip of the benzynering was suggested to account for the results [124, 1251. Later variabletemperature 1 11 and 1 3C NMR analysis of (113b) and its C6H3iPr analogueindicate that one CO ligand rapidly transfers between two Os atoms andthat opposite faces of the 113-benzyne ligand interchange during twodistinct fast intramolecular processes (Scheme 1-22) [126]. Variabletemperature 1 H and 13 C NMR studies of (114b) and its C6H3iPr analogueshow that the presence of only two Os-Os bonds does not interfere with the(C Os^Os(C0)3..-•E R2R2 E—Os(CO)2a, ER2=PMe2(113) b, ER2=AsMe23^„,‘,.._^1( C0)3Osr-^=--,Os (C0)31.....,,E R2(C0)3 OS2a, ER2=PMe2(114) b, ER2=AsMe2c, ER2=PEt2 (115)45interchange of the benzyne ligand faces which is accompanied byreversible hydride migration from one Os-Os bond to the other [126).(a)1C012Osme2E.7 \tei 4,421C0130C-1::^0 s(C012{C0 )2Os14,71lNNE,mt,Istto,20,— - —0 KohI0Ico),^•Os14 2 E, t„„Eb14e 2100/20s —0s1C0/3(b)IC0)2Os^MI;E,^tbMt?I^IMPS^1t0)21C01 2Os1C01205 ^ 0510012O^J01001 2Os10 2 F. k..c,^14 21001 2 0s^Z--s- 0510017Scheme 1-22 Two rapid intramolecular processes proposed for 0s3(g3-C6H4)(AsMe2)2(C0)7.The proposed structure of (115) can be related to (51) by openingthe Os(1)-0s(2) bond and attaching an extra CO to Os(2), or can be relatedto (114) by replacing one CO on Os(3) with PMe2Ph and coupling the ortho-position of the phenyl group to the benzyne moiety. A crystal structuredetermination is needed to confirm this new type of structure. Thestructure of (116) is also a proposed one and the PMe2Ph ligand isassumed to be on Os(3) (compare with (50), (51), (114) and (115)). If thestructure is correct, it is closely related to (114) and (115) by coupling theortho-position of the phenyl group with the benzyne moiety.Pyrolysis of 0s3(C0)10AsMe2(2-MeC6H4)] gives the unexpectedisomer HOs3(t3-4-C6H3Me)(AsMe2)(C0)q (117). Similarly 0s3(CO)ii(AsMe2(2-Me0C6H4)) and 0s3(C0)11[AsMe2(4-Me0C6H4)1 both give the 3-methoxy-46Me2Ph\s3^H•^1(C ) 3/p Me2Os 2(CO)3(116)362ods^(Js(co)3cco)N 2 /p erOs(C0)3(119)(C0)3OS^Os(CO)N As Me2Os(00)3(117)OMe(co)N sA c:32Os(00)3(118)benzyne cluster HOs3(1/3 - 3 -C6H30Me)(AsMe2)(C0)9 (118) [128]. No otherisomers of these complexes were produced in these reactions. Amechanism involving hydrogen atom transfer between metal and µ3-benzyne that proceeds via a-phenyl intermediates was proposed toaccount for these migration reactions [128].Another member of the (114) structural series is complex HOs3(i.L3-C6H4)(PC4H2Me2)(C0)9 (119), obtained in very low yield from the pyrolysisof 0s3(C0)11(PhPC4H2Me2) in heptane. It was characterized by using X-raycrystallography [129]. The hydride is assumed to bridge Os(1)-0s(3) bond.Another complex (120), similar to (114) and (119) containing SMe in placeof AsMe2 was isolated in low yield from the reaction of 0s3(CO)12 with3H-Os^'ids(C0)3(C0)32 eo■S MeOs 1(C0)3(120)2s 0)3OS3^12 ,(C0)3^OSNP /(C0)3, 1a, R=Et(121) b, R=Mec, R=Ph47MeSPh. An analogous complex containing SiPr is also known [130]. Thestructure of (120) was also determined and it is the only known clustercomplex where a bonded benzyne moiety is derived from a sulfide ratherthan a phosphine or arsine [130]. Variable temperature NMR studies of(120) show that, in addition to hydride migration between the Os-Osbonds, there is a higher energy process involving inversion at sulfur [130].The similarity of the structures of (120), (114), and (119) is apparent.Another series of complexes 0s3(113-C6H4)(PR)(C0)9 (R-Me, Et, and Ph)(121) which possess a different type of benzyne coordination was obtainedby refluxing 0s3(C0)11(PPh2R) (R-Me, Et, and Ph) in n-nonane [131]. Thestructure of (121a) was determined by an X-ray diffraction study. Theopen 0s3 triangle is capped on one face by a phosphinidene group and theother face by a benzyne moiety. These complexes are highly fluxional,probably owing to a rocking motion of the benzyne ring such that the twobenzyne carbon atoms become equivalent [131]. These pyrolysis reactionshave been re-examined in an attempt to isolate possible intermediatesinvolved [132]. The structures of (121b) and a PEt3 substituted derivative(122a) have been determined [133]. Reactions of (121b) with PEt3, PCy3,and P(OMe)3 give mono- and di-substituted products 0s3(113-C6H4)(PMe).Me^ i Me2Os 0)3(C0)203Sr I2NolsN AC0)3R3 P2p1Mea, R=Et(122) b, R=Cyc, R=OMe(.301(3,)pciso)_os 0)3OSAsi^3(4-meC6I-14)(124)3(4-MeC6F14)3A9-0s ^OsirOS 0)32 (CO)2 ^.01C0)3AS1(4-Me06 1-14)(125)48(C0)8(PR3) (R=Et, Cy, OMe) (122) and 0s3(µ3-C6H4)(PMe)(C0)7(PR3)2 (R=Etand OMe) (123) [133]. Both (122) and (123) exist as two isomers as shownin Figure 1.6. A detailed NMR study shows that the C6H4 ligand is rapidlymobile in (121b) and in the isomer of (122) with the ligand L at the centralOs atom. An exchange mechanism involving a symmetrical intermediatewas proposed to complement the rocking motion initially proposed [133].The fluxionality is substantially suppressed when L is coordinated at aterminal Os atom. The movement of the non-bonded Os Os edge aroundthe metal triangle also occurs, but slowly [133].0 (c0)3^(C0)2L^0 (C0)2L /0\PO)3OsZI \Os(C0)2L COO ^Os/ \ Os(C0)2 1- Os^OdC0)21-1^11(C0)\ V^(CO X y^(CO) I/ L(CO) I/P MeMe(122)Figure 1.6 Isomers of complexes (122) and (123).An analogous complex of (121) but with .t3-C6H3Me and As(4-MeC6H4) in place of g3-C6H4 and PR respectively, is obtained by heating0s3(C0)11(MeCN) with one equivalent of As(4-MeC6H4)3 in nonane [134,135]. The structures of (124) and its As(4-MeC6H4)3 derivative (125) weredetermined and in both structures the methyl group is on the 4 position ofthe benzyne moiety as in (117). These two structures resemble thebenzyne complexes (121) and (122) respectively.PMemajor isomer^minor isomer^major isomer^minor isomer(123)Me49Other phenyl containing ligands including benzene itself can reactwith 0s3(CO)12 or 0s3(C0)12- n (MeCN)n (n=1, 2) to give benzyne complexes.This is the most attractive route to benzyne complexes, but as yet no highyield synthesis has been developed. The parent compound H20p3(113 -C6/1 4)(CO)9 (126) is obtained in ca. 30% yield by heating benzene with 0s3(CO)12at 195 .0 [136, 137] or with 0s3(CO)10(MeCN)2 under reflux [138]. Thestructure of (126) reveals that the benzyne is bound to the 0s3 unit in afashion found in some other cluster benzyne complexes such as (49) and(106). The hydrides are assumed to bridge the longer Os(1)-0s(2) and3 0„.• - 4,„__OS -.•^c--0S(C0)3(C0)N/ / HOS..•••2(CO)3(126)Os(1)-0s(3) vectors. The hydride ligands in (126) are equivalent on theNMR time scale at room temperature, probably because of rapid rotationand/or flipping of the C6H4 unit and rapid reversible hydride migrationbetween the metal triangle and the benzyne ring [139]. The structure maybe related to (50) by replacing the PPh3 group with CO and the PPh2moiety by a terminal CO and a bridging hydride. The C6H3R (R-Me, nPr,CH-CHPh, Cl) and C6H2Me2 analogues of (126) have also been preparedfrom the reactions of Os3(CO)10(MeCN)2 with appropriate arenes. Thecomplexes derived from toluene and chloro-benzene exist in solution asmixtures of positional isomers (Figure 1.7) [138].5023 ,..^.V.,__ 1OS t--^=--- OS (C0)3(C0)N /)HOS 2(C0)33OS --^OS (C0)3(CO)N / %/ H, ..••••Us 2(C0)3Figure 1.7 Positional isomers of benzyne complexes derived fromtoluene and chlorobenzene (X=CH3, Cl).Complex (126) can also be obtained from thermal decarbonylation ofHOs3(g2-COPh)(C0)10 [1401 or HOs3(11-0CH2Ph) (CO)10 [141, 1421 derivedrespectively from C6H5CHO or C6H5OH. Photo-induced isomerization of theface-capping benzene complex 0s3(C0)9(p.3-7) 1 312—: 1 _T1 C6H4) [143] also leads to(126).Some important bonding parameters for the determined structuresof 0s3 benzyne complexes are summarized in Table 1-5. The numberingschemes are shown in Figure 1.8 with the structural types.The skeleton of the complex (49) is very similar to that of theruthenium complexes (106) except that in the Rua structures, the Ru(2)-Ru(3) bonds are longer than Ru(1)-Ru(3) by 0.02 to 0.06 A while in (49),Os(2)-Os(3) and Os(1)-Os(3) are the same. The structures of (50) and (51)are very similar to (49) with Os(1)-0s(3) being the longest and Os(2)-0s(3)the shortest; the benzyne ligands donate two electrons via two a bonds(0s(1)-C(2) and Os(2)-C(1)) and two electrons via a 7t bond (C(1) and C(2) toOs(3)) to the cluster. Structure (126) has a similar benzyne ligand donatingfour electrons, but the metal framework is somewhat different in that the512,4„._3 0 s^TOpsp( Ch 02 )3Phl------poost 1(49)^3^1^(COOS^ ,--Os(C0)3N2,,,..xOs(CO)3(114b) X=AsMe2(119)X=PC4H2Me2(120)X=SMe(C)Os(1)-0s(2) bond is much longer than Os(1)-0s(3), in contrast to that foundin (50) and (51), while Os(2)-Os(3) remains the shortest. In fact, the Os(1)-Os(2) bond at 3.026(2) A (3.041(2) A) is long compared to the Os-Os bond(A)2N fic!,^- 1/C:'1xs C°(c01 12(126) X=H, Y=CO(50)X=PPh2, Y=PPh3(51)X=PPh2, Y=Ph2P(C6H4C6H3)(B)2,Os 0)3OS^126012 (C0)1,1-a0)3X(121a) X=PEt, Y=CO(121b) X=PMe, Y=CO(122a) X=PMe, Y=PEt3(124)X=As(4-MeC 6H4), Y=CO(125)X=As(4-MeC 6H4) , Y=As(4-MeC6H43 1 R=MeR=11(D)Figure 1.8 Numbering and structural types of 0s3 benzyne complexes.52Table 1 -5. Important bonding parameters for the determined structures of 053 benzyne complexes .a(49)b^(50) (51) (126)c (114b) (119)c (120)^(121a) (121b) (122a) (124) (125)(A)^(B) (B) (B) (C) (C) (C) (D) (D) (D) (D) (D)Os(1)-0s(2) 2.985(2)^2.892(2) 2.881(2) 3.026(2) 3.929(5) 3.835(2) 3.791(1) 2.929(2) 2.917(1) 2.890(1) 2.936(1) 2.928(2)(2.975(1)) (3.041(2)) (3.837(2))03(2)-003) 2.796(2)^2.739(2) 2.715(2) 2.751(2) 2.839(4) 2.820(2) 2.833(1) 2.789(2) 2.782(1) 2.795(1) 2.807(1) 2.789(3)(2.785(2)) (2.751(2)) (2.819(2))Os(3)-03(1) 2.797(2)^2.918(2) 2.960(2) 2.866(2) 2.946(4) 2.922(2) 2.939(1) 4.008(2) d d 4.110(1) 4.131(1)(2.766(1)) (2.849(2)) (2.930(2))Os(1)-P(1) 2.35(3)^2.42(1) 2.42(1) 2.483(4) 2.398(7) 2.418(4) 2.306(9) 2.300(4) 2314(4) 2.406(1) 2.403(5)(As(1). S(1)) (2.387(7)) (2.396(6))Os(2)-111) 2.30(3)^2.26(1) 2.26(1) 2.482(3) 2.383(6) 2.433(5) 2.415(9) 2.402(4) 2.417(3) 2.542(1) 2.513(5)(Asti). S(^)) (2.333(7)) (2.388(7))Os(2)-P(2) 2.34(3)(2.361(7))Os(3)-P(2) 2.27(3)^2.37(1) 2.31(1) 2328(4) 2.427(5)( A 3(2)) (2.280(8))03(3)-P(1) 2.335(8) 2.331(4) 2.321(3) 2.435(1) 2.447(4)(As(1))Os(1)-C(2)^2.17(3) (d) 2.09(4) 2.14(4)^2.11(3)^2.198(13)^2.15(2)^2.19(2)^2.13(3)^2.13(2)^2.13(1)^2.113(8)^2.15(3)^(2.09(4)) (2.16(3))Os(2)-C(1)^2.12(3)(d) 2.22(4) 2.20(4)^2.07(3)^2.138(19)^2.12(2)^2.10(2)^2.17(3)^2.17(2)^2.17(1)^2.191(8)^2.07(6)(2.01(4)) (2.11(2))Os(3)-C(2)^2.14(3)(d) 2.42(4) 2.59(4)^2.31(3)^2.296(15)^2.29(3)^2.35(2)(2.33(4)) (2.34(2))0313)-C(1)^2.33(3)(d) 2.38(4) 2.26(4)^2.37(3)^2.388(14)^2.37(3)^2.37(2)^2.31(3)^2.32(2)^2.33(2)^2.323(8) 2.31(6)(2.4613)) (2.40(3))C11)-C(2)^e (d)^e^e^1.45(5)^1.436(22)^d^1.42(2)^1.53(5)^1.39(2)^1.44(2)^1.42(1)^1.42(6)kilA^ (1.64(6))benzyne to 6913^6913^6913^63.9^d^69.0^71.5^58.9^60.7^72.3^d^d033 plane^(65.8) 169.0)references^67 (116)^68^68^138^126^129^130^131^133^133^134.135^135a. All bond lengths in A and angles in *. b. The unbracketed values are from reference 67 and the bracketed values fromreference 116. c. Two crystallographically distinct molecules are present and values in brackets are for the second molecule.d. Data not given. e. Only average value 1.42(4) A for C6 rings is given and no significant variations are found.distance of 2.877(3) A in 0s3(CO)12.Structure type (C) includes (114b), (119), and (120) containing onlytwo Os-Os bonds, and Os(1)-0s(3) bond is about 0.1 A longer than Os(2)-Os(3). The open edge is symmetrically bridged by AsMe2 or PCHCMeCMeCHor SMe moieties. The benzyne ligand interacts with 053 via two a bondsand a it bond and thus donates four electrons. It is interesting to note thatthe benzyne C-Os bonds have similar lengths for the structural types (A),(B), and (C).The final structure type (D) also contains two Os-Os bonds withOs(1)-0s(2) being longer than Os(2)-0s(3) by ca. 0.1 A. These complexescontain a triply bridging group X. The central Os(2)-P(1) or Os(2)-As( 1 )bond is longer than the other two by ca. 0.1 A. The bonding of the benzynemoiety in (D) is different from that in the other three types, and it isthought to donate two to four electrons, thus bonding contributions from(127a) and (127b) were proposed [131]. Recently Deeming et al. [133], onthe basis of the structures of (121b) and (122a), proposed that (127c) is abetter bonding representation for benzyne moieties in type (D) structures.(127a) (127c)They argue that (127b) would show a long C(1)-C(2) bond and a Os-C(1) bond with double bond character, which is not found in these55M-OsMx -C1-2.87 A(121b)M-RuMx -C1-2.69 AMy-Cr 2.6 6 A(107a)RPxM-RuM 1 -C1-2.39 AMy-Cy-2.39 A(108a)structures. Both structures (127a) and (127b) would show a benzyne ringperpendicular to the Os3 plane which is not the case [1331.Although more structures have been determined for osmium clusterbenzyne complexes than for ruthenium, very little data were given on thebonding of the benzyne moieties in these osmium complexes. Data givenare often not sufficiently accurate to allow assessment of the bonding inthe benzyne moiety. Generally, no significant differences are found in theC-C bond lengths and even C(1)-C(2) bonds are little affected, in contrast tothat found in ruthenium complexes (e.g. Figure 1.5).It seems that osmium systems normally retain their metal triangleframework. While the bonding mode of the benzyne moiety is not veryflexible, the Os3 core and the bridging ligands are very flexible. Inruthenium systems, there is a high tendency for the cluster to fragmentand to recombine to form Ru4, Ru5, and Rub clusters. In all known Rucluster benzyne complexes the metal cores are closed, but the bondingFigure 1.9 Structures of (121b), (107a), and (108a) with CO groupsbeing omitted [1331.56mode of the benzyne moiety is more flexible.Deeming et al. [133] made interesting structural comparisons ofcomplex (121b) with related ruthenium compounds (107) and (108)(Figure 1.9). In (121b) and (107a), the extent of direct bonding to the 13-carbon atoms is slight, but in (108) both the a- and 13-carbon atoms arestrongly bonded to the metal atoms. If the above argument is valid, it hasan interesting implication that the benzyne complexes on ruthenium andosmium clusters are closely related. For example, the ruthenium analogueof the osmium benzyne complex type (D) is probably somewhat unstable,but if provided with extra electronic and/or steric stabilization it might beisolable. Cullen et al. [121] have isolated a ruthenium cluster complexcontaining a (benzyne)chromium tricarbonyl moiety Ru3(C0)9[PC6H5Cr(C0)3][C6H4Cr(C0)3] (128). The presence of the Cr(C0)3 moiety andthe interaction of the chromium atom with the ruthenium atom, albeitweak (Cr-Ru 3.097(1) A), may be responsible for the stabilization of thestructure. The Rua core is open as found in 0s3 structure type (D). Anotherexample is the isolation of complex Ru3(C0)9(AsMe2)(H)1C6H4Cr(C0)31 (129)[144]. This is a novel type of structure and may also be stabilized by aninteraction between chromium and one osmium atom (2.9704(6) A).Another interesting complex Ru3(C0)8(PtBu)[C6H4Cr(C0)31 (130) shows asymmetrically bonded aryne moiety [145]. This is another new type ofaryne structure both for ruthenium and osmium systems. A Cr-Ru bond of2.920(1) A is present and again this may be of great importance instabilizing the novel structure.A further interesting prediction of the above argument is that a type(B) structure for osmium may also be found for ruthenium, that is, acomplex like H2Ru3(C0)9(aryne) may be obtained if provided with some571(CO)3C r1Ru (CO)3Rt(C0)3tPBu(130)Cr (CO)3(CO)(CO)Ru^Ru (CO)3C6H5Cr(CO)31(128)(C0)3Cr(C0)2Ru Ru (C0)3\ /MG2As-Ru (CO) 3(129)stabilization. On the other hand, it would be rather difficult if not possibleto assemble osmium benzyne complexes analogous to the Ru4, Ru5, and Rubones due to the strength of the Os-Os bonds and the thermodynamicstability of these known benzyne complexes.1.2.4 Dinuclear 112-Benzyne (11-o-Phenylene) ComplexesSmall amounts of the dinuclear benzyne complexes H0s2(C0)6(AsMe2)(C6H4) (131) and 0s2(C0)6(AsMe2)2(C6H4) (132) were obtained inaddition to (113b) and (114b) when 0s3(C0)11(AsMe2Ph) and 0s3(C0)10(AsMe2Ph)2 were pyrolyzed [125]. Analogous compounds were notobtained from the corresponding PMe2Ph complexes.Complex (133) was formed in low yield via an unstable hydrideCpIr(C6H5)(H)(CO) by irradiating a benzene solution of CpIr(C0)2 [146]. Itsstructure reveals that the benzyne ring is largely unperturbed withaverage C-C distance being 1.379(3) A. Ir-Ir and Ir-C bonds are 2.7166(2)and 2.045(3) A long respectively. Double oxidative additions of 1,2-diiodobenzene to a dipalladium complex Pd2(Ph2PCH2PPh2)3 gives benzynecomplex (134) [147]. Direct trapping of tetrafluorobenzyne, generated by58(C0)30s^Os(C0)3 (00)30s^Os(C0)3AsMe2^Mee As As Me e(131) (132)OC(133)the decomposition of C6F5MgEr in dioxane, with Fe3(C0)12 affords (135)[148, 149]. Reaction of C6F5Li with Fe(C0)5 followed by treatment withMe3SiC1 also gives (135). A similar reaction with Co2(CO)8 as trappingreagent gives a tetra-nuclear species [Co4(C0)10(C6F4)] [148]. Reaction of[PtC14]4 with Ph3CC1 in benzene at 50°C gives complex (136) the structureof which has been determined [150]. The Pt-C distance is 1.97(2) A andthere is no Pt-Pt bonding (3.258(2) A) involved. Reduction of trans-(PEt3)2Ni(C1)(2-C1C6H4) with lithium generates (137), a dimer of thebenzyne complex (PEt3)2Ni(C6H4) that was the anticipated product of thereaction [110]. Complex (137) is in equilibrium with (138) (Equation 1.10).^Ph2P^PPh2^I^I,Pd^PdI ' 1 IPh2P. PPh2(134)(CO)4Fe^Fe(CO)4(135)CISONC11:113:CC:Cl/ ICV Pt ^ Pt(136)259PEt3 pEt/ 3NiNiPEt3 PEt3(137)(142)Pd/NEt2 I ./(141)Palladation of N,N,N',Ni-tetraethyl-1,4-xylene-a,a'-diamine with PdC14 2-gives g2-benzyne complex (139) which can be converted to (140) and(141) 11511.The only known g2-benzyne complex involving a trinucleir cluster isH3(µ-1 2 -C6H4)(1..t-n 2 -HC-NPh)0s3(C0)8 (142) obtained from the pyrolysis ofH20s3(C0)10(CNPh) 11521. The hydrocarbon ligand bridges one edge of thecluster and the bond lengths of Os(1)-C(1) (2.107(10) A) and Os(3)-C(2)(2.165(9) A) are similar to those found in g3-benzyne complexes. Thephenylformimidoyl ligand bridges the Os(2)-0s(3) edge and is on theopposite side of the 0s3 plane from the benzyne moiety.EtaNiNiPEt3(138)+ 2PEt3^(1 .10 )NEt2\Pd'0Pd-0Pd'0^NEt2^NEt2^(139) (140)60In all the known dinuclear benzyne complexes, the benzyne moietyis bonded to two metal atoms via two a bonds. Relatively little effort hasbeen made to develop a systematic approach to these interestingcomplexes.1.2.5 Metal Complexes of BenzdiyneThe more highly unsaturated 1,4-benzdiyne (143) and (144) can alsobe stabilized by metal complexes. The free molecules have never beenobserved, and theoretical calculations suggest that their ring opening togive H-C-C--CEC-H is more favorable than the corresponding process forbenzyne to give H-C=C-H and H-CEC-CEC-H 133]. However, 1,2,4,5- and1,2,3,4-tetrabromoarenes do form Diels-Alder bis-adducts upon treatmentwith equivalents of an organolithium reagent in the presence of a suitablediene [153, 154].(143) (144)Complex (145) undergoes CH4 elimination on heating to give amixture of two pairs of isomeric benzdiyne complexes (146) and (147)(Scheme 1-23) [155]. The isomers in each pair differ in having anti- orsyn-arrangements of the PMe3 ligands. The 1,4-dimethoxy-substitutedanalogues of (145) give a pair of isomers (148a) and (148b) (Equation61/PMe3Cp2ZrfrCp2PMe3(147a)Cp2ZrMe OMeOMeZrCp2 0/pMe3MeCp2ZrMe0/PMe3Cp2ZrM e(145)PMe3/PMe3Cp2Zr— O —Zr CP2(146b)PMe3Cp2ZrCp2Zr--. OrZrCP2PMe 3 0>Z1 rCp2PMe3PMe3(147b)^(146a)Scheme 1-23 Synthesis of the benzdiyne complexes (146) and (147).1.11). The structure of (148a) was determined [1551. Complexes (148a) and(148b) undergo insertion with unsaturated organic molecules such asacetone, 2-butyne, and ethylene to give bis(metallacycles) (Scheme 1-24).The compounds derived from ethylene, (149a) and (149b), can beconverted to tetrahydrodicyclobutabenzenes (Equation 1.12).^OMe Me3P^OMe/^PMe3 OMe/P/Ae3Cp2Zr- 01-2rCP2 + Cp2Zr--t j0--ZrCp2 ( 1 . 1 1 )/ YPMe3OMe^OMe(148a) (148b)62OMe OMeOMe^OMeCP2Zr^ZrCp2 0ZrOMe^CP2 OMeOMeZrCp2OMeBr^BrBr^BrOMeH2C=CH2Me2CO(148a)(148b)MeCECMeBr2+ /CP2Zr^ZrCp2 CP2ZrOMeOMeZt*FP2ZrCp2Zr^ZrCp2 ZrCP2 0Me^Cp2ome(149a)^(149b)OMeOMe1.12)tBuLiOMeOMeOMeOMeScheme 1-24 Reactions of the benzdiyne complexes (148a) and (148b).(149a) 12(149b)Reaction of the 4-fluorobenzyne nickel complex (150) with a largeexcess of lithium tetramethylpiperidine (LiTMP) in the presence ofNi(Cy2PCH2CH2PCy2)(C2114) affords the 1,4 -benzdiyne complex (151)(Equation 1.13) [156]. This success was inspired by the observation thatchlorobenzene reacts with a base such as LiTMP to generate benzynewhich can be trapped by added nucleophiles such as 1,3-diphenylisobenzofuran (Equation 1.14) [157].63CY2^Cy2 CY2LiTMP \—Ni /NiCY2^CY2 Cy2Cy2(1.13)Cy2(150) (151)Ph^CICO +Ph PhLiTMP(1.14)PhThe structural analyses of (148a) and (15 1) show that thecoordination geometries are similar to those of the corresponding benzynecomplexes (70) and (96). In both complexes the metal atoms are situatedslightly away from the plane of the aromatic ring (0.17 and 0.08 A for(148a) and (151) respectively). The bond lengths and angles are shown inFigure 1.10.Even more highly unsaturated 13,5-benztriyne (C6) could bestabilized by coordination to transition metal fragments to form a complexsuch as (152) [1581.M^M(152)64OMeBond lengths (A) Bond angles (°)C(1)-C(2) 1.345(11) C(1)-C(2)-C(3) 121.1(6)C(2)-C(3) 1.398(11) C(2)-C(3)-C(4) 118.8(7)C(3)-C(4) 1.401(10) C(6)-C(1)-C(2) 120.1(6)C(1)-C(2) 1.313(12) C(1)-C(2)-C(3) 124.1(9)C(2)-C(3) 1.402(13) C(2)-C(3)-C(4) 112.2(8)C(3)-C(4) 1.417(13) C(6)-C(1)-C(2) 123.6(9)Figure 1.10 Comparison of the bond lengths and angles of the 1,4-benzdiyne moieties in (148a) and (1 51)127].1.3 Ferrocyne and Its Transition Metal Complexes1.3.1 Aromaticity of FerroceneFerrocene, (n5-05H5)2Fe (153), was discovered by Kealy and Pauson(159], and by Miller et al 116 0]. The description of the isoelectronic cationicCo(III) complex soon followed 11 6 11. These were the first examples of whatwould become a wide range of sandwich compounds. The correct structureof ferrocene was first proposed 11 6 2] and later confirmed by a crystallo-graphic study which also showed that the two cyclopentadienyl rings65adopting a staggered configuration [1631. The most recent crystallographicstudy, however, shows that the two rings are eclipsed [1641.Ferrocene is unusually stable for an organoiron compound. It doesnot undergo Diels-Alder reactions, resists catalytic hydrogenation undernormal conditions, and resists pyrolysis at 470 .0 [162, 1651. In 1952,Woodward et al. reported that ferrocene undergoes Friedel-Crafts acylation[166, 1671. Shortly after this discovery, ferrocene was shown to undergoother aromatic-type substitution reactions including alkylation [168, 1691,formylation [170, 1711, mercuration [1721, and sulfonation [1731. Some ofthese reactions are summarized in Scheme 1-25. Typical aromatichalogenation and nitration reactions can not be carried out directlybecause ferrocene is easily oxidized to the ferricenium ion FeCp2+ which isinert to attack by electrophiles. Ferrocene can easily be metalated,especially with n-butyllithium, and the lithiated products are very usefulfor preparing a wide variety of ferrocene derivatives. Some examples aregiven in Scheme 1-26.66MeCOFeMeCOEt—OEtHgOAc^/4kluoi^H C=CH2MeCO —(0)CH3COC Fe16)AICI3(c3)--Hg0AcFe(1.(2)----Hg0Ac\Br2AlC13^Fe(.(17) E t—((1))Fe+ FeBr4"HCHOHF^HOH2C—C)FeCH2 NMe2CH2NMe2^ HOH2C ^Fe(61 HOH2C-6)HCHO/HNMe2HOAcScheme 1-25 Some typical reactions of ferrocene (153) (adaptedfrom reference 308).1.3.2 FerrocyneAlthough the parallel between ferrocene and benzene has long beenestablished, the evidence for the existence of ferrocyne is rather limited.The reactions of haloferrocenes with strong bases could involve ferrocyneintermediates, but such reactions are expected to be more difficult thanthose of halobenzenes due to the electron rich nature of the metalloceneand the higher strain in forming a formal triple bond in a five-memberedring. However, the simple cyclopentadienyl anion seems to be capable of67Fe(153)nBuLiTMEDACD ---"°2Feproducing a benzyne analogue. Thus when a solution of potassium 1-diazo-cyclopentadiene-2-carboxylate (154) is heated in benzene containingdicyclohexyl-18-crown-6 and tetracyclone, some of the product (155) canbe isolated after protonation [174] and an intermediate such .as (156) islikely to be involved.XER2ER2 0--ER2N204^12ER.P, As^Q^Li C( '^Li-i)) —F ^+^Fe E=P, As^Fe1. CO2 (C.:L.))^6)—ER2. H30+(0)—COOH (c3--COOH(OR)320Fe^+^Fe(),—NO2c) — B(OH)2Fe^+^Fe\_B(OH)2Fe6.)--COOH(0)---ER36Fe + Fe6ER3NO21.B(OH)2Scheme 1-26 Some reactions of mono- and 1,1'-dilithiated ferrocenes(adapted from reference 308).Huffman et al [175] found that the reaction of chioroferrocene withn-butyllithium gives n-butylferrocene and biferrocenyl and proposed a68(156)ferrocyne intermediate. However a different reaction pathway involvingmetal halogen exchange followed by metathesis can not be excluded,though it is not very likely (Scheme 1-27). Much stronger evidence for a(154) (155)o c'CCFbe) ^Fe^Fe(CINT B u^.))OF' Fe + "BuLi^Fe(1) + "BuCIScheme 1-27 A possible pathway for the reaction of FcCI with nB uLinot involving a ferrocyne intermediate.ferrocyne intermediate was later provided from the reaction of asubstituted haloferrocene with nB uLi, as shown in Scheme 1-28 [176]. Thisreaction is remarkably similar to those of substituted halobenzenes ornaphthalenes and it clearly indicates the involvement of a ferrocyne69C I CILiFe^"Bu Li^Feie)Fe^+Me Meintermediate (157).(157)Scheme 1-28 Reaction of a substituted chloroferrocene with nB uLi.1.3.3 Transition Metal Complexes of FerrocyneBy analogy with benzyne, ferrocyne could conceivably be stabilizedby coordination to one or more transition metal centers. Some 5-membered ring aryne complexes bonded to 0s3 clusters are known. Inparticular, complex (158) is formed by oxidative addition of pyrrole or N-methylpyrrole (R-Ii or Me) to 0s3(C0)12 [177]. A more satisfactory route tosuch complexes is from the 2-formyl substituted derivatives that addoxidatively to 0s3(C0)10(MeCN)2 to give acyl clusters. Heating these acylclusters results in decarbonylation to give products such as (158), (159),and (160) (178-1801. However, the oxidative addition product (161) offerrocene carboxaldehyde at 0s3(C0)10(MeCN)2 does not decarbonylateeven when one CO is replaced by a labile MeCN ligand (1811. The directreaction of ferrocene with 0s3(C0)12 is reported to give no tractablematerials [181]. The ruthenium analogue of (161) does undergodecarbonylation, but the product is ferrocene with no evidence for ferro-70cyne complex formation being obtained [182].By analogy with benzdiyne and benztriyne, more highly unsaturatedferrodicyne species such as (n 5 -05H3)Fe(n 5 -05H3) and (71 5 -05H)Fe(11 5 -05H5)could also conceivably be stabilized by coordination to transition metalfragments. Again nothing is known about such species.H - ■ k N,I rOs _^... Os(C0))----.H ---- (C0)3H - CN 3,Os _^...0s(C0).■ H •-••"" (C0)3Fc^0 C0)3/IH I^Os --.(CO)4\Os Os^Os(CO)\ H •-'- (C0)3 (CO)3(158) (159) (160) (161)Pyrolysis of Ru3(C0)10(PFcPh2)2 affords the benzyne complex (106b)in good yield with no indication of ferrocyne complex formation [119].Similarly Ru3(C0)10(bPpf) affords a number of products including twobenzyne complexes (106c) and (107c) [120]. This same reaction affords arather interesting complex (162) containing an ortho-metalated Cp ringand some iron-ruthenium interaction, certainly encourages furtherresearch in preparing cluster complexes containing the ferrocyne moiety.^I^LpPli2ph2 Pi^Ru —Ru^(C0)3^/(CO)2H—Ru(CO)3(162)71Chapter 2 Syntheses and Pyrolytic Reactions ofSome Triruthenium and TriosmiumPhosphine and Arsine Complexes2.1 IntroductionTogether with cyclopentadienes and phosphines, carbon monoxide isone of the most important ligands in transition metal organometallicchemistry. Transition metal carbonyls are common starting materials forthe synthesis of other low-valent metal complexes. The carbonyl ligand cannot only be substituted by a large number of other ligands such as Lewisbases, olefins and arenes, but the remaining CO groups stabilize themolecules against oxidation or thermal decomposition.Transition metal carbonyls are among the earliest known classes oforganometallic compounds. The first binary metal carbonyl complex,Ni(C0)4 (163), was prepared a century ago by the reaction of Ni metal withCO [183]. Similar reactions led to the preparation of Fe(C0)5 (164) [184,185]. The action of light on Fe(C0)5 (164) affords the dinuclear Fe2(C0)9(165) [185].COCOOC—Fe1 •- COCO(164)OCN 0^OC_,_^COFe— /OCR^(Fe- C00 0 C CO(165)72The first metal cluster carbonyl complex, Fe3(C0)12 (166), wasobtained by heating non-aqueous solutions of Fe2(C0)9 [186]. The firstruthenium carbonyl complex obtained by Mond et al. [1871 is Ru3(CO) 2(167), but it was not correctly formulated until an X-ray crystallographicanalysis was performed [1881. Improved preparations have beenfrequently reported, and these usually start from hydrated rutheniumchloride [189]. The first osmium carbonyl complex, 0s3(CO) 1 2 (168), wassynthesized by Hieber and Stallman [190). Better synthetic routes havebeen developed starting from 0s04 [191].(CO)3 1..1Fe --f`jn/(C0)4 Fe^Fe(C0) 3(166)Ru (CO)4(CO)4/ \Ru^Ru(CO)4(167)(CO)4 OS(CO ) 4Os/ Os(CO)4(166)Most binary metal carbonyl complexes are prepared by the action ofcarbon monoxide on metal compounds under reductive conditions withsodium, aluminum alkyls, and carbon monoxide itself being the mostcommon reducing agents.Transition metal carbonyl compounds are not limited to neutralspecies, and large number of cationic and anionic complexes are known. ACO +OC COReOC^COCO(169)CO -OC% I COOeNCOCO(170)NbCo 3CO0C—^-, --coCO(171)73few examples are Re(C0)6* (169), V(C0)6 - (170) and Nb(C0)5 3- (171). Thecarbonylate anions are very useful for the preparation of mixed dinuclearand polynuclear metal carbonyl complexes.The strength of metal-metal bonds increase with the atomic numberof the metal, and as a result, polynuclear metal carbonyl complexes aremore common for second- and third-row transition metals. Carbonyls canbridge two or three metals, but such tendency decreases down a column inthe periodic table. The energy difference between a structure with CObridges and one without them is often small, as illustrated by the fact thatCo2(C0)8 exists in solution as a mixture of isomers (Equation 2.1) [1921.These carbonyl bridges are very important in the fluxional processes inthese complexes.0(CO) 4Co Co(CO)4 (C0)3Co —Co(C0) 3 ( 2.1 )•■1(0Carbonyls form a great many polynuclear complexes with group 8metals. Anionic species are especially common in high nuclearity clusters,as are bridging hydride ligands and interstitial atoms [1931 such ashydrogen, phosphorus, arsenic, sulfur, and particularly nitrogen andcarbon. Four structures (172)-(175) are shown to illustrate the diversebonding interactions in these clusters.The structures of Ru3(C0)12 (167) and 0s3(C0)12 (168) are analogouswith M3 forming a triangle and four terminal carbonyls on each metalcenter, two being axial and two equatorial [194, 1951. Some structural data74(00)2^ (C0)3Ru Ni(C0) 3 Ru -^-Ru(C0)3^‘,C0.\-\ ..'^RuI(C0)3^(CO)Ni/- - - ''' ..7 r°), ...Co(C0) 3 R __.....:(Ni CO). 1/Ni(C0) 3Ni5(C0)122-trigonal bipyramidal Nis(173)Ru5N(C0)14 -square pyramidalRu5(172)(CO) PtOo^P(CO)CO(CO)Pt ---- - -" t(CO)OC t^^co(CO)^Pt6(C0)12 2 ^Os10C(C0)242-trigonal prismane Pt6^tetra-capped octahedral(174)^ (175)are summarized in Table 2-1. The metal triangles are essentially equi-lateral, and all CO groups are linear although there is a tendency for theaxial ligands to bend due to van der Waals repulsions between axialoxygen atoms.75Table 2-1. Structural data for Ru3(C0)12 (167) and 0s3(C0)12 (168).Ru3(C0)12 0s3(CO)12Av. M-M (A) 2.854(4) 2.877(3)M-C (axial) (A) 1.942(4) 1.946(6)M-C (equatorial) (A) 1.921(5) 1.912(7)C-0 (axial) (A) 1.133(2) 1.134(8)C-0 (equatorial) (A) 1.127(2) 1.145(5)M-C-O (axial) (°) 173.0(10) 175.3(10)M-C-O (equatorial) (`') 178.9(10) 178.4(10)2.2 Syntheses and Structures of Some Triruthenium andTriosmium Phosphine and Arsine Complexes2.2.1 Triruthenium Phosphine and Arsine ComplexesThe reactions of Ru3(C0)12 with phosphines or arsines are commonlyeffected by thermal or photochemical methods. Both techniques often leadto cluster fragmentation. For example, irradiation of a hexane solution ofRu3(C0)12 and PPh3 gives only a low yield of Ru3(C0)11(PPh3); mononuclearRu(C0)4(PPh3) and Ru(C0)3(PPh3)2 are the major products [196]. Thethermal reaction generally leads to trisubstituted product except with verybulky phosphines such as PCy3 [1151. If chromatographic separation ratherthan crystallization is employed to treat the reaction products, mono- anddi-substituted products can be obtained from thermal reactions though thetri-substituted complexes often predominate [1151. The first mono- and di-phosphine substituted Ru3(C0)12 complexes were prepared by ligand76Ru^Ru■^Ru(CO)4^(CO)4(CO)4^Ru3(CO)i Ltransfer reactions between low-valent platinum tertiary phosphinecomplexes and Ru3(C0)12 [200].Benzems et al. [201] and Arewgoda et al. [202] first showed thatspecific CO substitution in metal carbonyl complexes can be electronicallyinduced. Since then a number of mild routes to CO substitution have beendeveloped. Bruce et al. [203] and Arewgoda et al. [204] reported that COsubstitution can be catalysed by Na/benzophenone radical anion (BPK). Theproposed mechanism for this electron transfer catalysed reaction onRu3(C0)12 is outlined in Scheme 2-1 [205]. The investigation of theelectrochemical behavior of Ru3(C0)12 and related species has shed furtherlight on the mechanism [206, 207]. It has been shown that Ru3(CO)12 -radical (t112-10 -6 s) rapidly isomerizes to an open structure Ru3(CO)12 -w(t1/2 -10-6 s) which can either dimerize or undergo a redox reaction.Two requirements have to be met for the catalysis to occur: (1) thecluster carbonyl has to be reduced without fragmentation, and theresulting anion has to have a long enough lifetime for substitution to takeplace; (2) to facilitate the electron transfer from the substituted radicalRu3(CO)12[Ph2CO] -[Ru3(CO)12]^[Ru3(co)liqRu3(C0)12 Scheme 2-1 The proposed mechanism for BPK catalyzed mono-substitution of Ru3(C0)12.77anion to the unsubstituted one, the substituting ligand must be a betterLewis base than the carbonyl ligand. Thus: (1) the efficiency of BPKcatalysis decreases with increasing substitution; (2) weak coordinatingligands such as AsPh3 and SbPh3 give moderate or low yields of theproducts. For most phosphines, either monodentate or bidentate, themono-, di-, and tri-substitution proceeds readily in high conversion andspecificity with no fragmentation being detected [205, 2081. This methodhas allowed many previously unknown phosphine and arsine complexes tobe prepared.The second method of activating Ru3(CO)12 towards substitution wasdescribed by Lavigne and Kaesz [2091. A catalytic amount of PPN+0Ac . orPPN+CN - was found to promote CO substitution of Ru3(CO)12 by tertiaryphosphines such as PPh3, dppe, but not by AsPh3. Other PAN* salts showvarying degrees of activity and the reaction presumably involves anionattack at a CO group as the first step. Nucleophilic attack of phosphinefollowed by CO loss and regeneration of the catalytic anion leads to thesubstituted product. It is also possible that the anion attacks a CO groupand decarbonylation leaves the anion attached to a ruthenium center. Theanion can then easily be replaced by a phosphine. Detailed study of thereaction mechanism is apparently needed.CO substitution of Ru3(CO)12 by phosphines has also been facilitatedby methoxide anion [210, 2111, (CpFe(CO)212 [212, 2131 and EFe(C0)2L(µ-SMe)]2 (L-CO, PPh3) 1214]. A comparative study of the thermal, BPK, and[CpFe(C0)2]2 catalyzed routes suggests that the 1CpFe(C0)212 route, whichmay involve iron carbonyl anion, is superior for those reactions reported[2151. Again more research work is needed to establish the generality andscope of these little studied reactions.78One potentially very useful strategy involves the activation of thecarbonyl by Me3NO. Since phosphines or arsines are susceptible tooxidation by Me3NO, the carbonyl is usually activated with Me3NO in thepresence of a labile ligand such as MeCN, this labile ligand can then bereadily replaced [2161. Both Ru3(C0)11(MeCN) and Ru3(C0)10 (MeCN)2 havebeen prepared by using low temperatures [217]. The complexes are quiteunstable so further development is necessary to establish it as a simpleand convenient method [2181.With the advent of these mild synthetic methods to Ru3(C0)12derivatives, considerable interest in their chemistry has developed andmany complexes are thus known. The most common structural types ofmonodentate (L) and bidentate (L-L) tertially phosphine and arsine substi-tuted Ru3(C0)12 complexes are Ru3(CO)1 IL (176) (L=PPh3, PCy3, AsPh3,PMe3, PMe2Ph, P(2-MeC6H4)3, P(4-MeC6H4)3, PEt3, PPh2Py, Ph2P-CE---C-Rwhere R=tBu, iPr, Ph), Ru3(C0)10L2 (177) (L=PPh3, PMePh2, PMe2Ph, PMe3,AsPh3, PCy3, P(CH2CH2CN)3), Ru3(C0)9L3 (178) (L=PMe3, PMe2Bz, PMe2Ph,AsMe2Ph, PMePh2, PEt3, P(3-MeC6H4)3, P(4-MeC6H4)3, P(CH2CH2CN)3, PPh3,PnBu3, AsMe2Bz, PEtPh2, Ph2P-CEC-tBu), Ru3(CO)8L4 (179) (L-PMe3,PMe2Ph), Ru3(C0)10(L-L) (180) (L-L-dppm, dppe, dppp, cis-dppee, ffars,CH2=C(PPh2)2, f6fos, dmpm, dpam, dpae), Ru3(C0)8(L-L)2 (181) (L-L=dppm,dppe, ffars, f6fos, dmpm, dpam), Ru3(C0)11(71 1 -L-L) (182) (L-dppe),(Ru3(C0)11)2(L-L) (183) (L-L-dppm, dppe, dppa), Ru3(C0)10LL' (184)(L-AsPh3, L'-P(4-MeC6H4)3), Ru3(C0)9(L-L)1; (185) (L-L-dppe, L'-PMe3)[115, 196-200, 205, 212, 218-246, 295, 297, 301]. PF3 is the only ligand atpresent known to displace more than four CO ligands [2421. For bidentateligands, Ru3(C0)6(L-L)3 (L-dppm and cis-dppee) have been isolated andcharacterized spectroscopically [243, 244].79(CO)4CO/Ru COI/ \ IL'—Ru^Ru —LCO/L,(184)(CR0)4^(CRu0)4,/ \ RujC0)3 (COR )3/^RuTc O)4^NL^V (CO)4(183)COCO3 1CO3C11u COI/ O\ IL-'—Ru^RuI°C/ CO^CO CO(185)(CO)4Ru NCO ICOt80)4^I 'CO(176)(C0)4?CyRu\COL Ru^Ru LCO/&D,(177)CQ.A:0,Ru/ CO\ IOC-Ru^Ru—LL/C0^CCP°(178)COL \ i / C0L—Ru c^° ‘Ru—LCO/L, &jL(179)COCO/ 17uL.., I LnCOccj,‘ I „_Ru--Ru1 IOC. coCO CO(CO)4 1-Thu CO\ I^Ru% R)4^ COCO((181)^ 182)Bruce et al. [219-223, 226, 247] among others [196, 224, 225, 227,229, 230, 248] have carried out an extensive structural study of some ofthese complexes. Crystal structures have been determined for Ru3(C0)111,(176) (L-PPh3 [196], PCy3 [219], PPh(OMe)2, AsPh3 [220]), Ru3(CO)10L2(177) (L=PPh3 and PPh(OMe)2 [221]), Ru3(C0)9L3 (178) (L-PMe3 [219],PMe2Ph, AsMe2Ph, PMe2Bz, PPh(OMe)2 [222]), Ru3(C0)81.4 (179) (L-PMe2Ph[223], PPh(OMe)2 [247]), Ru3(CO)10(L-L) (180) (L-L=dppm [224], dppe(226], ffars [227b], H2C-C(PPh2)2 1229], PhP(CH2)(C6H4)PPh [230]), andRu3(C0)8(L-L)2 (181) (L-L-dppm [225] and ffars [227a]). All thesecomplexes have the structures shown above except for Ru3(C0)880(PPh(OMe)2]4 (186) which adopts a structure with two carbonyls asymme-trically bridging the shorter Ru-Ru bond (2.797(1) A) [247]. The other twoRu-Ru bonds are identical at 2.879(1) A and the molecule represents theonly known example of a Ru3(C0)12 derivative with the Fe3(CO) 12 typestructure. Another interesting structure is Ru3(C0)9(g3-(PnBu2)3SiMe) (187)in which the tridentate ligand caps one face of the Rua triangle and thereare three asymmetrically bridging carbonyls. The Ru-Ru bonds at 2.917(1)A are longer than those of Ru3(C0)12 (2.854(4) A). Bent semi-bridgingcarbonyls are also found in the solid state structures of Ru3(C0)10(PPh3)2[221, 249] and possibly of Ru3(C0)8(PMe2Ph)4 [223]. The tendency for theformation of bridging CO groups is expected to increase with more electrondonating phosphines and with more CO groups being replaced byphosphines [223].Studies of the structures of monodentate phosphine and arsinecomplexes of Ru3(C0)12 have resulted in the following generalizations[223]: (1) Phosphine and arsine ligands invariably occupy equatorialcoordination sites. In di-, tri-, and tetra-substituted complexes, the bulkyligands occupy positions so that they are as far as possible from each other.(2) As the degree of substitution increases, so does the degree of distortion(Me0)2PhPx5 PPh(OMe) 2RuICOOCR /CC) /PPh(OMe)2(Me0)2Php—Ru^Ru–00OC/ */COCio(186)Me/Si^P "Bu2"Bu213 "Bi 2 P\oc4;Ru (CO)2(C0)2Ru /COO Ru (C0)2C(187)81Ph2Ru,P(C0)u4^ (C0)3N.(C0)3Ru pPh2F(188)from D3h symmetry in Ru3(C0)12 to D3 symmetry by a twisting of theRu(CO)nL4-n groups about the Ru-Ru bonds. (3) Introduction of the group15 ligands results in a lengthening of the Ru-Ru bonds For Ru3 (CO)11Lcomplexes, the Ru-Ru bond cis to the ligand L is affected the most and thelengthening correlates well with the cone angles of the ligands. ForRu3(C0)101.2 complexes, no pronounced lengthening of such cis Ru-Ru bondsis observed, though the Ru3 core is expanded. (4) In general, the averageRu-Ru distances increase with increasing degrees of substitution except in(186) where there is a change in structure type.For bidentate ligands, the Ru-Ru bond distances show two differenttrends depending on particular ligands as summarized in Table 2-2. Indppm and H2C=C(PPh2)2 complexes, the bridged Ru-Ru bonds are shorterthan the unbridged ones. In dppe complex, all the Ru-Ru bonds havesimilar lengths and they are almost the same as those in Ru3(C0)1 2(2.854(4) A). In ffars, PhP(CH2)(C6H4)PPh, and bppf complexes, the bridgedRu-Ru bonds are longer than the unbridged ones. The trend is mostapparent in Ru3(C0)10(bppf) (188) where the bridged Ru-Ru bond at2.9284(5) A is significantly longer than the other two (2.8600(4) A) [2501.In Ru3(C0)8(ffars)2 (189), while the bridged Ru-Ru bonds are not differentfrom those in Ru3(C0)12, the unbridged one is shortened to 2.785(4) A.(C0)3^(C0)3Aspie2\^r-**/Ru (CO)2As N AsMe2 Me2 F2(189)82Table 2-2. Ru-Ru bond distances for some Ru3(C0)10(L-L) and Ru3(C0)8(L-L)2 complexes.Complexes^L-L bridged L-L unbridged^ReferencesRu3(C0)10(dppm)^2.834(1) 2.841(1), 2.860(1) 224Ru3(C0)8(dppm)2^2.833(2), 2.826(2) 2.858(2) 225Ru3( C0)10[CH2 =C(PPh2)2]^2.836(1) 2.862(1), 2.840(1) 229Ru3(C0)10(dPpe)^2.856(1) 2.855(1), 2.847(1) 236Ru3(C0)10(ffars)^2.858(6) 2.831(3), 2.831(3) 227bRu3(C0)8(ffars)2^2.853(3), 2.853(3) 2.785(4) 227aRu3(C0)10[PhP(CH2)(C6L4)PPh] 2.884(1) 2.851(1), 2.848(1) 230Ru3(C0)10(bppf)^2.9284(5) 2.8600(4), 2.8600(4) 250Recently, Cullen and coworkers [250] have prepared and characteriz-ed a number of ferrocenylphosphine derivatives of Ru3(C0)12. Theseinclude Ru3(CO)1 IL (L=PFc3, PFc2Ph, PFcPh2), Ru3(C0)101.2 (L=PFc2Ph,PFcPh2) in addition to Ru3(C0)10(bppf). The structure of Ru3(C0)11(PFcPh2)was determined and, as expected, the Ru-Ru bond cis to the PFcPh2 ligandis 2.9000(6) A being longer than the other two at 2.8641(6) and 2.8560(7)A [250].2.2.2 Triosmium Phosphine and Arsine Complexes0s3(C0)12 is more robust than Ru3(C0)12 and a wide variety ofreactions can be carried out without any change of nuclearity. 0s3 systemsare often quite stable to heat and air, they are easily crystallized, so their8 3chemistry has been extensively studied. The very inertness of thesesystems has allowed the isolation of many interesting compounds other-wise unavailable [1131A large number of reactions leading to triosmium phosphine andarsine derivatives are known, these involve either the parent 0s3(C0)12 orits derivatives that contain labile ligands such as MeCN.Substitution of CO groups in 0s3(C0)12 by phosphines and arsines hasbeen effected by thermal and chemical methods. Photochemical activationof 0s3(C0)12 towards substitution has been little studied 12511.Conventional thermal reactions involving 0s3(C0)12 and phosphinesor arsines are still widely used because, unlike the reactions of Ru3(CO)12,the rates of the second and third substitutions are not much different fromthat of the first, so a mixture of mono-, di-, and tri-substituted products isusually obtained. By controlling stoichiometry the desired product can beobtained in good yield although chromatographic separation is oftennecessary.Chemical activation of 0s3(C0)12 has been achieved with Me3NO,which was first introduced by Shvo and Hazum [253] to removecoordinated CO groups through the formation of CO2. Since phosphine andarsine are also susceptible to oxidation by Me3NO, the direct reaction of0s3(C0)12 with phosphine/arsine in the presence of Me3NO is not oftenused. Other chemical means of activation include the use of Pt(PPh3)4 [2521and [CpFe(CO)212 [215a]. Nas[Ph2C01 - is found to catalyze the substitution ofphosphine or arsine on 0s3(C0)12 but the activity is low [2031.Substitution of 0s3(C0)12 derivatives containing labile ligands is themost useful method for preparing mono- and di-substituted derivatives.Phosphines and arsines react with these derivatives with great specificity84(00)4^(00)4OS co Os co Ph(00)4/S co\iOs^Os—00(00)4 I(190)(CO)4Os(00)3/ \Os(191)Os"^O\I s PMe2Ph(C0)4^I ',PMe2PhCO(192)POs/ `o(00)4^I `ps.)co Ph2(193)under mild conditions.Activation of 0s3(C0)12 by Me3NO in the presence of a labile ligandsuch as MeCN has been used to prepare 0s3(C0)11(MeCN) and 0s3(C0)10(MeCN)2 [255, 2561. The latter complex was also prepared by the reactionof 0s3(C0)10(C8H14)2 (C8H 14-cyclo-octene)with MeCN [2541. The cyclo-octene and butadiene derivatives 0s3(C0)10(s-cis-C4H6) (190) and0s3(CO)1o(s-trans-C4H6) (191) are also very useful starting materials [2571.The structures of (190) and (191) have been determined [257, 2581 Thebutadiene is bonded to one osmium atom and occupies one axial site andone equatorial site in (190), while in (191) it occupies one equatorial siteon two adjacent osmium metal centers. The s-cis-butadiene complex (190)has been used by Deeming et al. to prepare some unusual isomers such as1,1-0s3(CO)1 o(PMe2Ph)2 (192) [259] and 1,1-0s3(CO)10 (dppe) (193) [260,2811. The structures of 0s3(C0)11(MeCN) (194) and 0s3(C0)10(MeCN)2 (195)were also determined, and the MeCN ligands occupy axial positions. Theaxial CO ligands trans to the MeCN ligand have the shortest Os-C bonds12611.Some common structure types for phosphine and arsine derivativesof 0s3(C0)12 are 0s3(CO) j IL (196) (L=PPh3, P(4-MeC6H4)3, P(SiMe3)3, Ph2P -CEC-tBu, Ph2P-CEC-Ph, PMe3, PEt3, PMe2Ph, AsMe2Ph, PEt2Ph, PMePh2,Me2As-CH=CH2, PEtPh2, PnBu3, Ph2P(CH2)2Si(OEt)3, Ph2P-CH=CH2, Ph2P(2-85(CO)4MeCN(C0)4°s CO(COs/ sLO)4^I 'COCO(196)(C0)4^(C0)4^os MeCN Os0/ \os(C0) 3 Os/ \Os(C0)3(CO)3^IMeCN(194)^(195)(c0)4,os co/ \ I Los^os(CO)4^1 • Lco(197a)COCOIfi s COOs --C°\01(CO)4^I 'COCO(199a)(C0)4,^Ios co/ os-os(CO)4^• Lco(199b)CH2-CHC6H4), AsMe2(2-MeC6H4), AsMe2(2-Me0C6H4), AsMe2(4-Me0C6114),As(4-MeC6H4)3), 0s3(C0)10L2 (197) (L-PPh3, PMePh2, PMe2Ph, PMe3, PEt3,AsMe2Ph, PhPC4H2Me2, AsMe2(2-MeC6H4), AsMe2(2-Me0C6H4), AsMe2(4-Me0C6H4), P(4-Me0C6H4)3, PEt2Ph, AsMe2(CH-CH2), PEtPh2, PnBu3, P(4-MeC6H4)3, Ph2P(CH2)2Si(OEt)3, Ph2P(CH-CH2), Ph2P(2 - CH2-CHC6H4)),0s3(C0)91,3 (198) (L-PPh3, PMe3, PEt3, PMe2Ph, AsMe2Ph, PEt2Ph,AsMe2(CH=CH2), PnBu3, P(4-MeC6H4)3, PMePh2, Ph2P(CH2)2Si(OEt)3),0s3(C0)10(L-L) (199) (L-L-dppm, dmpm, dppe, dppp, dppb, H2C-C(PPh2)2,cis-dppee, f4fos), 0s3(CO)8(L-L)2 (200) (L-L=f4fos, H2C-C(PPh2)2).0s3(C0)9(L-L)L' (201) (L-L-dppm, L'-PPh3), 0s3(C0)1 i(L-L) (202) (L-L=dppm, dppe, dppp, dppb, dmpm, f4fos, f8fos, dppa), (0s3(C0)11)2(L-L)^(C0)4^(CO)4^COC0Os OsI ,OsCO / ■OC Os^Os-L L-OsO/ ‘ COV \ I^CO/ 1 \ OC17 CO\ II/ \ IOCOs -L OC Os^Os -LCO' I^I •CO COC°^I/ICO^coCo CO/ COI\COI^L^L/ CO^I •COC°(197b) (197c)^(198a) (198b)(CO)4coA co17 \ IL-os Os-LCOL cozi \ 1 LI 1!)Os co1--... 1/ co \I / 1-OS^OSOC1 Li^Co CO(200)86COo cAlc^, coo\IOs_OCR co^co co(201)(CO)4/os\I .„,Los7^os(C0)4^I coco(202)(CO)4^(CO)4Os ,Os\ (CO) (COOs^Os^Os)3/^Os(C0)4L^L/ (C0)4•(203)(203) (L-L-dppm, dppe, dppp, dppb, dmpm), 0s3(C0)10(L -L)2 (204) (L-L-dppe, dppp) [69, 124, 125, 136, 137, 220, 221, 231, 235, 243, 244, 255,259, 260, 262-287, 292, 296, 297]. It is clear that 0s3 derivatives showmore isomers than those of Rua especially in di- and tri-substitutedmonodentate phosphine complexes and in bidentate phosphine complexes.Linked clusters of the type [0s3(C0)10(dppa)] n (n=3, 4) have also beenisolated [279]. Tetra- and higher-substituted phosphine derivatives of0s3(C0)12 are unknown although complexes 0s3(C0)12-n[P(OMe)3]n (n-4-6)have been described [272, 288, 298].(--\(c0)3L^'OsOs^Os(C0)4^(CO)3(204)CO Ph 2PPh2 COQ I ,P.---,C0i9s, CO \V CO\ I ,PPh2Ph2P Os^OsOC' L^I 'COco(205)Crystal structures have been determined for complexes 0s3(C0)11L(L-PPh3 [220], PPh(OMe)2 [220], Ph2PNHPh [289], tBu2PNH2 [294]),0s3(C0)101,2 (L=PPh3 [221], PPh(OMe)2 [221], (CF3)2PNPPh3 [290]),0s3(C0)9(PPh3)3 [222], (0s3(C0)11)2(dPPa) [279], 1,2-0s3(CO) io[H2C-C(PPh2)2][244], 1,2-0s3(C0)10(dPPe) [286], 1,1-0s3(C0)10(dPpe) [291], and 0s3(C0)9(n211-dppm)(Til-dppm) (205) [291]. All phosphines occupy equatorial87coordination sites in these structures and no bridging carbonyls arepresent. The only complex in which two of the axial CO ligands have beendescribed as semi-bridging is 0s3(C0)9(g3-11 2 -C2Et2)(PPh3) [293]. Formonodentate phosphine complexes, the generalizations observed in Ru3derivatives are also valid for the osmium analogues. In (0s3(C0)11)2(dPpa)the two Os-Os bonds cis to the phosphine at 2.903(3) 2.907(3) A are longerthan the rest which average to 2.879(3) A [2791. The complex 1,1-0s3(C0)10(dppe) has the structure (199a) and the two Os-Os bondsinvolving the dppe bound Os atoms (2.913(1) and 2.914(1) A) are longerthan the other (2.889(1) A) [2911. The complexes 1,2-0s3(C0)10 (dppe)[286] and 1,2-0s3(C0)10(cis-dppee) [2441 have the same structures as(199b) and the Os-Os bonds have similar trends as in the Ru3 analogues.0s3(C0)1 2 derivatives containing ferrocenylphosphine ligands wereunknown prior to the present work.2.3 Pyrolytic Reactions of Some Triruthenium and TriosmiumPhosphine and Arsine ComplexesPyrolysis of phosphine or arsine substituted Ru3 and 0s3 carbonylcomplexes often leads to intramolecular C-H and/or C-P(As) bondcleavages [2991. Many cluster benzyne complexes described in Chapter 1are derived from a phenyl group on phosphorus or arsenic through theseintramolecular reactions.2.3.1 Pyrolytic Reactions of Some Triruthenium Phosphine ComplexesPyrolysis of Ru3(C0)9(PR3)3 (PR3-PPh3, PMePh2, P(3-MeC6H4)3, P(4-88PPh2Ru(C0)3(208),Ru^Ru^kC0)3 Ru‘(C0)3N/(C0)3^Ph2PR2R2 =Ph2 or MePh(207)2Ru-Ru(C0)3 E /R2(C0)3a, ER2=PPh2b, ER2=P(3-MeC6H4)2c, ER2=AsPh2(206)12(C0)2 / NRU- Ru(C0)3/PPh3 0=C\Ph(209)MeC6H4)3) in decalin gives some dinuclear complexes (206a), (206b), (207),and (208), besides the benzyne complexes (106a) and analogues [115]. Atlower temperatures in refluxing toluene, Ru3(C0)9(PPh3)3 also affords thedinuclear complex (209) in addition to (106a) [300]. Pyrolysis ofRu3(CO)i (AsPh3) gives dinuclear arsenido complex (206c) and penta-nuclear complex (210a) 18]. Pyrolysis of Ru3(CO)11(PMe2Ph) gives (210b)in addition to the benzyne complex (109) 11181 The benzyne complexesresult from one aryl C-H and two aryl C-P cleavages without clusterbreakdown, while the other complexes result from both C-H and/or C-Pcleavages and Ru-Ru bond cleavages. Complex (208) results from two arylC-H cleavages, (207) results from one aryl C-H cleavage and one aryl C-Pcleavage, (206) results from two aryl C-P cleavages, and (209) results fromone aryl C-P cleavage and a CO insertion into the phenyl group. The crystalstructure of (209) shows the two ruthenium atoms and bridging acyl to becoplanar: the Ru-Ru distance is 2.750(1) A [300]. The formation of (106a),(208) and (207) probably involves ortho-metalation as the first step, butthat of (209) indicates that C-P cleavage can take place without C-Hcleavage. The structure of (210) contains a Ru5P or Ru5As octahedron withthree CO groups on each metal center. Its formation involves two sp 2 C-P89cleavage reactions in addition to complex metal framework rearrangement.The pyrolysis of Ru3(C0)11(PPh2R) (R-Ph, Me, CH2NPh2), studied byKnox et al. [117, 118], affords the benzyne complexes (106a), (107a-c), and(108). The formation of (106a) from Ru3(C0)11(PPh3) involves a redistri-bution of the phosphine ligand together with two aryl C-P and one aryl C-Hcleavages. The formation of the other complexes involves two aryl C-Pcleavages and one aryl C-H cleavage. Bonnet and coworkers found that thecomplex Ru3(C0)11(PPh2Py) loses CO at ambient temperature to yield anacyl complex (211) [301]. The formation of (211) involves one aryl C-Pbond and one Ru-Ru bond cleavages together with a CO insertion, and anintermediate (212) with phosphido and a o-bonded phenyl group isbelieved to be involved. The Ru-Ru bond involving oxygen bondedruthenium in (211) at 2.821(1) A is shorter than the other one at 2.877(1)A.ER)3NCO—RuRu^u(C0)3(CO)NR ( C° )3a,ER=AsPhb,ER=PMe(210)N(CO) R p--Ph\\CO )3Ru^Ru(CO) c=ePh/(2 1 1)%1‘1\I(C0)3FX PhRu^FC1 ) 3(C0)4 (CO)(212)(C0)4 Ru(C0)3/ \(C0) 3Ru^RuPPh 2( 2 13)(CO)Complex (213) readily converts to the hydrido-alkyne cluster (214)at 40 .0 and to a Ru4C2 cluster (215) at higher temperatures [216, 302].This chemistry is centered on the more reactive hydrocarbon group. Cartyet al. found that pyrolysis of Ru3(C0)11(Ph2P-CEC-R) leads to Ru2(C 0 )6(PPh2)90(CF-C-R) and likewise Ru3(C0)9(Ph2P-CEC-R)3 leads to Ru3(Ph2P-CEC-tBu)(PPh2)2(42 -CE-C - tBu)(112 -B2-CEC-tBu) (216) [237, 276]. The structure (216)has Ru(1)-Ru(2) length of 3.139(1) A and Ru(1)-Ru(3) length of 3.05(1) A[237].Heating (Ru3(CO)11)2(dppa) results in the formation of the penta-nuclear cluster (217), and this definitely involves many steps but only onealkynyl C-P bond cleavage [295]. Ru3(C0)8(dppm)2 converts to the openRu3 complex (218) upon heating at 130 6C [246]. The structure wasdetermined and the open Rua triangle is capped on one face by thephosphinidene moiety and the other face by a metalated phosphinemoiety. The dppm bridged Ru-Ru bond at 2.843(1) A is shorter than theH^/PPh2Ru"*".- —Ru(CO ) 2(CO) 3^/Ru"(C0) 3(214)C\(CO)tBuCmC—PPI12/1\/tBu(C0)2—Ru 3I. U (CO)3(C0)2^pph2(COR)2u\\^pRu(CO) 3 Ph2.^(C0)2^CtBU(215) (216)Ph(C2Ru,PPh2Ru\p_ciFicuo)2Ph/ Ph H(217)^ (218)Ph- MCPh2(CO)3 Ru^Ru hPh(219)(C0 )2h2C OF) I2U ‘71\ \P7RU (CO)3(CO)38:61\ P)718(^8)391other one at 2.884(1) A. One aryl C-P, one alkyl C-P and one alkyl C-H bondare cleaved in forming (218). An intermediate complex (219) has beenisolated in a controlled pyrolysis 13031. The structure consists of atriangular array of metal atoms involving two metal-metal bonds with thedppm bridged Ru -Ru bond at 3.205(1) A being much longer than the otherone at 2.888(1) A. In fact, the longer Ru-Ru bond in (219) is the longestRu-Ru bond known. The face-capping moiety derived from dppm acts as aseven electron donor and results from one aryl C-H, one alkyl C-H and onearyl C-P cleavage. It is believed that a species of formula Ru3(C0)7(g-dppm)(1.13 -0 - PhPCH2PPh(C6H4)) is the antecedent of (219) 13031. A reactionsequence is proposed as shown in Scheme 2-2. The first step involves themotion of the phosphine from equatorial to axial position; orthometalationof a phenyl group and subsequent reductive elimination of a benzenePhPh2p2 (C0)2, PPh2P/ \ PPh2RuRu—riu(CO)3^(C0)3PhPh, F,Phi(C0)2 L\^2pph2(C:18)2^( 18109)3 Ph/H 1\C, PhRu(C0)2 Rit\ H—P&\\*/(C0),p -- (C0)2 h2Ph(219)Ph^CPhl(C0)4:1u- —P`.■9 ..H2z \(C0)3 RU^Ru —phN AC0)2 2Pi^Ph^(218)pP h2IScheme 2-2 A possible reaction sequence for the formation of (218)from Ru3(CO)8(dppm)2.92Ph........ p ,,Cti2 r...1_P "I.00)3Ru \ Ru(CO)3 (CO)3(220)molecule. C-H activation of the methylene bridge then leads to (219). Analkyl C-P cleavage followed by reductive elimination of the hydride withorthometalated phenyl gives the final complex (218).Pyrolysis of Ru3(C0)10(dppm) affords complex (220), a result of onearyl C-P and one C-H cleavage [230]. Orthometalation is presumably thefirst step and is followed by reductive elimination of a benzene molecule.The transformed phosphine-phosphido moiety donates six electrons to thecluster. The Ru-Ru bond distances (from 2.818(1) to 2.888(1) A) are closeto the values in the parent Ru3(C0)12. Thermolysis of Ru3(C0)10(dmpm) andRu3(C0)8(dmpm)2 leads to HRu3(C0)9(Me2PCHPMe2) (221) and HRu3(CO)7(dmpm)(Me2PCHPMe2), respectively [239]. The methylene C-H bond iscleaved preferentially and the transformed ligand caps one face of the Ru3triangle. The longest Ru-Ru bond is at 3.097(1) A and is thought to bebridged by the hydride, the other two Ru-Ru bonds are at 2.812(1) and2.804(1) A, respectively.Two reports concerning the pyrolysis of ferrocenylphosphinesubstituted Ru3(C0)12 derivatives have appeared [119, 120]. The formationof (106b) from Ru3(C0)10(FcPPh2)2 involves one phenyl C-H and twophenyl C-P cleavages [119]. Thermolysis of Ru3(C0)10(bppf) affordscomplexes (222) and (223), in addition to (162) and the benzyneHICMe2^P Metp/tr, p\1i \uIl73 (CO) RU ---- RU (CO)3\ H/(221)93(C0)3Ru—PPh2.pqu^I^\Fc'/(0-0)4 —....(638);pPh2Ph2PI\(C0)3Ru Fc'I_\(PCS) , Ru_p(C0)3 Ph2Fe)2^(CO)3(C0 /Flu,Ru— PPh2l'- (C0)2'Ph(106c)PhRu^'I (M)FcRu (CO)^Ru_pphH1CO)2^2(221) (222)ph2P1(cau3^.74)211—rcu0)3(162)complexes (106c) and (107d) [120]. The formation of (107d) involves atleast three C-P bonds and one C-H bond cleavage. Other complexes areincluded in a proposed reaction sequence shown in Scheme 2-3 [120]. Themotion of one phosphorus from an equatorial to an axial position leads toeither ferrocenyl orthometalation with subsequent Fe-Ru bond formationto yield (162) or phenyl orthometalation. The latter pathway goes furtherby aii 2Scheme 2-3 A proposed reaction sequence for the pyrolysis ofRu3(CO)10(bppf).94(226)PPh2Os (C0)3Ph^r‘3P—ws(CO)2 H'(C0 )3(224)P\Ph2Os (C0)3(CO) Os^Os-- PPh3/(C0)3H(225)(CO)2Os--pPh 2(CO) -- Os )3(001\ /PPhbonding interaction to give (222). Complex (222) may then undergo aphenyl C-P cleavage to form (223) or undergo one ferrocenyl C-P and onephenyl C-P cleavages to form (106c). The structure of (162) contains a longRu-Ru bond bridged by the two phosphorus atoms (3.037(2) . A) and arather short Ru-Ru bond bridged by the orthometalated ferrocenyl carbonatom (2.692(2) A). A Fe-Ru distance of 3.098(3) A indicates bondformation between these metal atoms. Such bonding is necessary for themolecule to be electron precise. Structure (222) contains a Ru3 trianglecapped on one face by the metalated phenyl phosphine moiety which actsas a five electron donor. Complex (223) contains a Ru3 triangle capped onone face by the phosphido moiety which acts as a four electron donor.2.3.2 Pyrolytic Reactions of Some Triosmium Phosphine and ArsineComplexesThermal decomposition of 0s3(CO)10(PPh3)2 affords complexes (224),(225), and (226) in addition to the three benzyne complexes (49), (50), and(51) [67-691. Both aryl C-H and C-P cleavages are involved in formingthese benzyne complexes, and (51) also contains a new C-C bond.Complexes (224) and (225), resulting from one aryl C-H cleavage, are quite95similar except that in (224) the axial phosphine acts probably as a fiveelectron donor while in (225) the metalated phenylphosphine remains inan equatorial position and is a three electron donor. Complex (225) is theonly isolated Os3 complex showing a simple orthometalated phenyl withoutan n2 interaction of that phenyl with the cluster. In both (224) and (225)the Os-Os bond cis to PPh3 is the longest (3.001(2) and 3.047(2) A),respectively). Complex (226) is rather unusual in that it has a bridgingphenyl group. One face of the 0s3 triangle is capped by the orthometalatedphosphido moiety acting as a four electron donor, similar to that in (222).Two aryl C-P bonds and one aryl C-H bond are cleaved in forming (226).All the three Os-Os bonds are quite long (3.095(2), 3.146(2), and 3.187(2)A) and the phenyl bridge is asymmetric (C-Os bonds 2.19(3) and 2.39(3)A). The postulated reaction sequence is shown in Equation 2.2 [69].0s3(CO)1o(PPh3)2---... (225) (224) (49) +(50) + (51) +(226) (2.2)The formation of the benzyne complexes (1 13)-(1 16) involves onearyl C-H bond and one or two aryl C-P(As) bond cleavages from PMe2Ph orAsMe2Ph [1251. No alkyl C-H and C-P bond cleavage products wereobtained in the thermolytic reactions of these phosphine or arsinesubstituted Os3 complexes, although dinuclear complexes (130) and (131)were formed in low yield as a result of aryl C-H and C-As cleavage [125].Pyrolysis of trialkyl phosphine complexes does result in alkyl C-H bondcleavage [263]. For example, heating 0s3(CO)11(PMe3) affords H20s3(Me2PCH)(C0)9 (227a) in 60% yield. 0s3(C0)11(PEt3), 0s3(C0)10(PMe3)2, and0s3(C0)10(PEt3)2 behave similarly to give (227b), (228a), and (228b)respectively [263]. While (228b) shows only one isomer, (228a) shows two96H^HHri Os (CO)3(C0)3//Os-(ao)3(230)PEt2)os(co 3(c8)H/iis0)3(229)isomers which are believed to differ in the coordination sites of the PEt3ligand. The structures of (227) and (228) are believed to be similar to thevinylidene complex 0s3(C0)9(H)2(113-71-C-CH2) [127]. Only the a C-H bondsare cleaved in PEt3 complexes. Pyrolysis of 0s3(CO)11(PEt2Ph) in nonaneaffords HOs3(Et2PC6H4)(C0)9 (229) and HOs3(EtPCHCH2) (CO)9 (230) inaddition to the benzyne complex (114c) [127]. It is interesting that informing (230) two alkyl C-H bonds and one aryl C-P bond have beencleaved.Two intermediates, (231) and (232), have been isolated andstructurally characterized in the transformation of 0s3(C0)11(PMe2Ph) to0s3(C0)9(13-PMe)(113-C6H4) (121b) [132]. A reaction scheme was proposedas shown in Scheme 2-4 (R-Ph, Me, Et). Complex (231) contains a 1.13-r1 2 -metalated phenylphosphine moiety, as in (224) and (229). Complex (232)contains a metalated phosphido capping moiety with a bridging carbonyl,similar to the ruthenium complex (223) or the osmium complex (226)where an equatorial bridging phosphido and bridging phenyl group replacethe bridging carbonyl and one terminal carbonyl. This complex is a rareexample of an 0s3 complex containing a bridging CO group. Thetransformation of (232) to (121) is very similar to that of the Fe3 clusterR^Ci P^ R2P R2Os„_(C0)3^I NOJC°)3I /^71 (C0)31 / F-I(C0)30sQs^Os----Os-PR3H4C0)3 40)2a,R=Me, R'=H^a, R=Me, R'=Hb,R=Et, R'=Me^b, R=Et, R'=Me(227)^(228)97Os 0)3(08) I3\ p /(i0)3(121)POS. (CO)3\--7C0R= Me(232)PRPh1)0s CO 3(C0)30k.,-714SN4PRPh1Os (C0)3(C0)30s^ s,N0)3R=MeR^(231)0s3(C0)11(PRPh2)(2.3)P (4- Me0C6H4)(CO)3(CO)3 Fe^Fe (CO)3PhScheme 2-4 Proposed mechanism for the pyrolytic reactions of0s3(C0)11(PRPh2).complex shown in Equation 2.3 [304].Thermolysis of 0s3(C0)11(PhPCHCHCHCH) gives ring opened products(233) and (234) [305], while 0s3(CO)11(PhPCHCMeCMeCH) gives (235) ingood yield in addition to a small amount of (119) [129]. The ring openedphosphido moiety in (233) and (234) is an eight-electron donor. The Os-Osbond involving the n3-ally1 bound osmium atom in (234) is of length2.948(1) A, while all other Os-Os bonds in (233)-(235) are somewhatPhP (-Me0C6F14)(COFe)^—Fe (CO)3 ^//Fe(CO)398Ph \(CO)2/,--Os(c013\---Os(0)3(233)PhPP CH(C 1  N/30s-0 HC 0)3Os(C0)3(234)shorter than those in 0s3(C0)12. Structure (235) is similar to (233) exceptthat the two carbon atoms bearing methyls are not coordinated.Pyrolysis of 0s3(C0)10(dpPm) in refluxing toluene produces complex(236) in high yield [273]. The crystal structure was determined and oneface of the 0s3 triangle is capped by the orthometalated phenyl phosphinemoiety. The metalated phenyl carbon bridged Os-Os bond at 2.747(1) A issignificantly shorter than the other two (2.844(1) and 2.834(1) A). Unlikethe common A-711,712 interaction of orthometalated phenyl rings found in(222), (224) and (231), the metalated phenyl in (236) interacts with twoosmium atoms through one carbon atom only and the molecule isunsaturated [3061. The reaction can be reversed by bubbling CO at 25 °C togive the starting material 0s3(C0)10(dPpm) via a stable intermediate 0s3(C0)9(H)(Ph2PCH2PPhC6H4) which contains an orthometalated C6H4 moietyH^ `^Me8C0)3\^(CO)K^Me-Os(C0)3 H(235)HI/ I \Me2P,c 1Pe P Me2I 73 `Os(C0)30s -Os (C0 )32^H / 1(237)(C0)2Os /)x-Ph2F—Os (CO) 3(COlj)n22--CI\(C9e)3 (88)3(238)99as in (225) [307]. The carbon bridge in (236) is symmetrical with C-Oslengths of 2.283(13) and 2.297(15) A. The structure of (236) might berelated to the ruthenium complex (162), but in the latter the unsaturationis compensated by a Fe-Ru dative bond. The thermal reaction behavior of0s3(C0)10(dppm) and Ru3(C0)10(dPPm) or Ru3(C0)10(dinm)2 is obviouslydifferent. The thermal reaction of 0s3(C0)10 (dmpm), however, iscompletely analogous to that of Ru3(C0)10(dmpm). Thus, heating 0s3(C0)10(dmpm) yields complex (237), the 0s3 analogue of (221) [2821. Like (221),the Os(1)-Os(2) bond at 3.104(1) is much longer than the other two(2.832(1) and 2.839(1) A). Pyrolysis of (0s3(C0)11)2(dppa) gives complex(238), analogue of (217) [278]. Similarly, heating 0s3(C0)11(Ph2P-Cr---C-R)(R-iPr, tBu, Ph) affords the P-C sp cleavage products 0s3(C0)9(CEC-R)(PPh2)[231, 276].2.4 Ferrocenylphosphines and Scope of the Present WorkThe aromaticity of ferrocene has led to the preparation andinvestigation of many derivatives analogous to those of benzene [308]. Theuse of ferrocenyl phosphines, arsines, and sulfides as ligands for transitionmetal complexes constitutes an important field of study.The first ferrocenylphosphine to be reported was triferrocenyl-phosphine PFc3 [309]. It was obtained from an unusual Friedel-Craftsreaction between ferrocene and PCI3 in the presence of AlC13 (Equation2.4). The first transition metal complex of triferrocenylphosphine to bedescribed was trans-bis(triferrocenylphosphine)chlorocarbonylrhodium,obtained from the reaction of PFc3 with [Rh(C0)2C1]2 [3101. Subsequent IR100studies of M(C0)5(PR3) (M-Cr, Mo, W), Fe(C0)4(PR3) and Mn2(C0)9(PR3)indicated that PFc3 is a much better a-donor ligand than PPh3 [3111.Similar studies show that the coordinating abilities of the phosphinesPFcPh2, PFc2Ph, and PFc3 increase with an increase in the number offerrocenyl groups [312].Fe ^+^PCI3 ^AlC13PFcCl2 + PFc2CI + PFc3^(2.4)C(1.).)The unsymmetrical tertiary phosphines PFc2Ph and PFcPh2 were firstprepared by using Friedel-Crafts reactions involving PhPC12 and Ph2PC1,respectively [3131. The 1,1'-phosphine substituted ferrocenes are readilyprepared in high yields since solutions of nBuLi and TMEDA readilydilithiate ferrocene and this product readily reacts with organohalo-phosphines [3141. These bidentate ferrocenylphosphines have been widelyused in preparing transition metal complexes, some of these complexeshave shown activities as homogeneous catalysts for hydrogenation andhydrosilation. In contrast, complexes of monodentate ferrocenylphosphineshave been little investigated.Studies of the reactions of mono- and bidentate ferrocenyl-phosphines with Ru3(C0)12 were initiated only a few years ago and thecomplexes Ru3(C0)10(bppf), Ru3(CO)III, (L-PFc3, PFc2Ph, PFcPh2) andRu3(C0)10L2 (L-PFc2Ph, PFcPh2) were characterized [119, 120, 2501.Ru3(CO)Io(bPpf) and Ru3(C0)10(PFcPh2)2 afford mainly benzyne complexesor intermediates to these benzyne complexes when pyrolyzed [119, 120].101Complexes Ru3(C0)11(PFcPh2) and Ru3(C0)10(PFc2Ph)2 have also beenstudied and evidence for the formation of some unusual compounds wasobtained [315]. At the time the present study was initiated, no 0s3(C 0 )12derivatives containing ferrocenylphosphines or arsines were known.The scope of the present work is:(1) to study the substitution reactions of ferrocenylphosphines, bothmonodentate and bidentate, containing alkyl or aryl groups, with Ru3(C0)12and 0s3(C0)12;(2) to establish the relative reactivities of alkyl, aryl, and ferrocenylC-H and C-P bonds towards oxidative cleavage on pyrolysis of thecomplexes prepared in (1);(3) to trap reactive species such as ferrocyne, which might begenerated through C-H and C-P cleavage, on the Rua and 0s3 clusters; and(4) to investigate other bonding interactions especially Fe(ferrocene)-M (e.g.(162)) dative bonding interaction which might bepresent in some of the pyrolysis products (Fe (ferrocene)-M bondinginteractions, although not common, have been found in a number of metalcomplexes [316-323]).102PART TWO: EXPERIMENTAL103Chapter 3 Experimental3.1 General Information3.1.1 MaterialsSolvents used in all the reactions were of reagent grade. Hexanes,cyclohexane, benzene, toluene, p-xylene, heptane, octane, cyclooctane,nonane, and decalin were refluxed over sodium benzophenone ketyl undernitrogen or argon and distilled prior to use. Diethyl ether, dichioromethane,and tetrahydrofuran (THF) were refluxed over LiA1H4 and freshly distilledunder nitrogen before use. Acetonitrile was refluxed over CaH2 undernitrogen or argon and freshly distilled prior to use. Tetramethylethylene-diamine (TMEDA) was distilled from CaC12 under nitrogen.Nitrogen and argon were Linde (Union Carbide) products and wereused without further drying and deoxygenating.All commercial reagents were of reagent grade and were used asreceived unless otherwise stated.Ferrocene, dichlorophenylphosphine, chlorodiphenylphosphine, 2-chloropropane, trimethylamine N-oxide dihydrate, and n-butyllithium (1.6M solution in hexanes) were obtained from Aldrich Chemical Co.. TMEDAwas obtained from BDH Chemicals Ltd.. Bis(triphenylphosphine)iminiumchloride (PPN -1- C1 - ), dichloroethylphosphine, chlorodiethylphosphine, chloro-di(tert-butyl)phosphine, and tris(1-naphthyl)phosphine were obtainedfrom Strem Chemicals. Diphenyl sulfide was obtained from K & KLaboratories, Inc.. Diphenyl disulfide was obtained from Eastman Organic104Chemicals. Diiodophenylarsine was obtained from Eastman Kodak Co..Meso-bis(tert-butylphenylphosphino)ferrocene was provided by T.-J. Kim[333]. Tris(1-naphthyl)arsine was prepared by Prof. W. R. Cullen.RuC13•xH20 was loaned by Johnson Matthey Ltd.. 0s3(C0)12 was obtainedfrom commercial sources.3.1.2 Reaction conditionsPreparation of Gringard reagents, chlorophosphines, ferrocenyl-phosphines, ferrocenylarsines, and ferrocenyl sulfides were carried undernitrogen or argon by using standard Schlenk vacuum line techniques [334].Pyrolysis experiments were carried out in a 250 or 100 mL, two-necked, round-bottom flask fitted with a reflux condenser which isconnected to a nitrogen or argon line and to a gas bubbler. Magneticstirring was initiated before heating was turned on. All the reactions weremonitored by thin layer chromatography (TLC) and the TLC plates wereMerck silica gel 60 F254 on aluminum (0.2 mm thickness) or Whatmansilica gel UV254 on aluminum (0.25 mm thickness). After the reaction wasstopped, the mixture was allowed to cool to room temperature, and thesolvent was removed in vacuo. In most cases, the 31 P and/or 1 H NMRspectra of this reaction mixture were recorded. Frequently, the solidresidue was dissolved in a small amount of CH2C12 and appropriate amountof column packing material was added. The solvent was then slowlyremoved to give a nice powdery sample and this then was loaded througha funnel to a column for separation. This technique is often, but not always,superior to the method of loading a solution sample via a pipette. It isimportant to prepare the powdery sample right before separation as theseclusters tend to absorb onto silica, alumina, or Florisil.1053.1.3 Chromatographic separationAll chromatographic separations were carried out in open air, andthe eluting solvents were of reagent grade and used without drying anddegassing. The low boiling (35-60°C) fraction of petroleum ether was used.The mixed solvent ratio refers to volume/volume ratio. To obtain pureligands, repeated chromatography was often necessary especially for thoseprepared in moderate to low yields such as PFc2Ph. Ligands were allchromatographed on silica, ruthenium and osmium complexes werechromatographed on silica, alumina, or Florisil. Silica (230-400 mesh) wasfrom Merck, Florisil (60-100 mesh) and alumina (neutral, activity I, 80-200 mesh) were from Fisher Scientific.3.1.4 CharacterizationElemental analyses were performed by Mr. Peter Borda of theChemistry Department.Low resolution Electron Impact (EI) mass spectra were recorded on aKratos MS-50 spectrometer with probe temperature typically at 120, 150,or 180°C. Fast Atom Bombardment (FAB) mass spectra were recorded onan AEI MS-902 or Kratos Concept II HQ spectrometer with 3-nitrobenzyl-alcohol as matrix and argon as exciting gas. These were all run by theChemistry Department Mass Spectrometry Services. The number given inparentheses for EI mass spectra is the intensity of the designated signalrelative to the base peak.All the 1 H NMR spectra were recorded on a Bruker AC-200E, VarianXL-300, Bruker WH-400, or Bruker AMX-500 spectrometer operating at200, 300, 400, and 500 MHz, respectively. Unless otherwise stated, all thespectra were recorded at room temperature in CDC13. All chemical shifts (8)106are .in ppm with tetramethylsilane (TMS) as external standard and allcouplings (J) are in Hz.All the 31 P NMR spectra were recorded on a Bruker AC-200E, VarianXL-300, or Bruker AMX-500 spectrometer operating at 81.0, 121.4, and202.5 MHz, respectively. Unless otherwise stated, all were recorded atroom temperature in CDC13 with broadband 1 H decoupling. Chemical shifts(5) are in ppm relative to 85% H3PO4 as external reference and allcouplings (J) are in Hz.All the 13 C NMR spectra were recorded on a Bruker AC-200E orVarian XL-300 spectrometer operating at 50.3 and 75.4 MHz respectively.They were recorded at room temperature in CDC13 with 1 H broadbanddecoupling. Chemical shifts (5) are in ppm relative to TMS as externalreference and couplings (J) are in Hz.X-ray single crystal structure analyses were carried out by Dr.Steven J. Rettig of the Chemistry Department Crystallographic Services.3.2 Preparation of Starting MaterialsReferences following a synthetic procedure to be described in thissection means that the synthesis follows a literature procedure.3.2.1 Preparation of triruthenium dodecacarbonyl Ru3(CO)12Triruthenium dodecacarbonyl Ru3(C0)12 was prepared fromRuC13•xH20 by using literature methods [189d, 335]. The apparatus used islocated on the roof of the chemistry building dedicated to high pressuresyntheses involving CO gas. Typically 4 g of RuC13•xH20 dissolved in 500107mL methanol was placed in a 2 L high pressure bomb. After installing thereaction container properly, CO was allowed to flush through the systemfor 5 min and the system was closed. The reaction pressure andtemperature were controlled to be around 50-60 atm and 120-130°C.After 20 h the reaction was stopped and the system was allowed to cool toroom temperature. The CO gas was carefully vented and the systemopened. The solution was filtered and the mother liquor recycled typicallyfor four times. The overall yield is around 75-85%. Pure Ru3(C0)12 wasobtained via extraction with hot hexane from the crude product andsubsequent evaporation of the solvent. Anal. calcd. for C12O12Ru3: C, 22.54;H, 0.00. Found: C, 22.61; H, 0.11.3.2.2 Preparation of chlorodi(iso-propyl)phosphine ClPiPr2 [336, 337]The Grignard reagent iso-propylmagnesium chloride was prepared asfollows.Magnesium turnings (24.3 g, 1.0 mol) and diethyl ether (400 mL)were placed in a 2 L, round-bottom, three-necked flask equipped with a500 mL pressure equalizing dropping funnel, a reflux condenser, an inertgas inlet, and a magnetic stirrer. The magnesium turnings were etchedwith a trace of iodine. The reaction was then started by the addition of iso-propylchloride (78.5 g, 1.0 mol) dissolved in diethyl ether (400 mL).Subsequently, the iPrC1 solution was added gradually to keep the solventat its boiling point (ca. 2 h). After the addition is complete, the mixture wasallowed to reflux for an additional hour.The above Grignard solution was diluted with diethyl ether to 1200mL and then added dropwise through an addition funnel to a stirredphosphorus trichloride (55 g, 0.4 mol) solution in diethyl ether (100 mL). A108white precipitate formed during the addition and the reaction mixture wasrefluxed for another two hours. The reaction mixture was then filteredthrough a medium porosity Schlenk filter into a flask under nitrogen. Thesolid was washed with diethyl ether (50 mL) twice, and the solvent wasthen removed by distillation at atmospheric pressure to leave a yellowishoil. This was further purified by vacuum distillation. The product obtainedwas an air-sensitive, colorless liquid (28 g, 65%). 31 P NMR (121.4 MHz,C6D6): 8 132.8. 1 H NMR (300 MHz, C6D6): 8 1.70 (septet of d, 2H), 0.96 (dd,12H). Anal. calcd. for C6H 14C1P: C, 47.22; H, 9.25. Found: C, 47.35; H, 9.39.The 1 H NMR spectroscopic data agree with those in the literature; the 31 PNMR spectrum was not previously recorded.3.2.3 Preparation of ferrocenyl ligands3.2.31 Preparation of ferrocenyldiphenylphosphine PFcPh2 [313, 315]n-Butyllithium (32 mL, 0.05 mol) was added to ferrocene (13 g, 0.07mol) in diethyl ether (75 mL). The solution was stirred at room temper-ature for 60 h after which it was cooled in a dry ice-acetone bath andPh2PC1 (9 g, 0.04 mol) added dropwise. The solution was allowed to warmto room temperature with stirring and left so for 2 h after which water (50mL) was added. The organic layer was isolated and the solvent evaporated.The solid residue was applied to a silica chromatographic column.Unreacted ferrocene (15%) was eluted by using petroleum ether. Thedesired compound PFcPh2 was eluted by using a petroleum ether/diethylether (2/1) mixture. Solvent removal in vacuo afforded the product as anorange solid (45%). 31 P NMR (121.4 MHz): 6 -16.9. 13 C NMR (100.6 MHz): 8109139.1 (d, J=9.8), 133.4 (d, J=19.2), 128.3 (d, J=13.8), 128.0 (d, J=6.8), 75.8(d, J=6.1), 72.8 (d, J=14.8), 70.7 (d, J=3.8), 69.0 (s). 1 H NMR (200 MHz): 87.48-7.14 (bm, 10H), 4.30 (m, 2H), 4.04 (m, 2H), 4.00 (s, 5H). Massspectrum (EI, 120 ° C): m/e 370 (P+, 100.0), 305 (12.8), 293 (36.4), 228(16.1), 186 (49.4), 121 (20.3), 78 (30.4), 56 (18.5). Anal. calcd. forC22F119FeP: C, 71.38; H, 5.17. Found: C, 71.42; H, 5.20. The 1 H NMR dataagree with those previously reported; the 31 P and 13 C NMR data were notpreviously recorded.3.2.32 Preparation of diferrocenylphenylphosphine PFc2Ph [313, 3151n-Butyllithium (63 mL, 0.10 mol) was added to ferrocene (25 g, 0.13mol) in diethyl ether (150 mL). The solution was stirred at roomtemperature for 60 h after which it was cooled in a dry ice-acetone bathand PhPC12 (7.0 g, 0.07 mol) added dropwise. The solution was thenallowed to warm to room temperature with stirring and left so for 2 hafter which water (50 mL) was added. The organic layer was isolated, thesolvent removed under reduced pressure, and the residue was applied to asilica chromatographic column. Unreacted ferrocene (25%) was eluted byusing a 20/1 petroleum ether/diethyl ether mixture. The desiredcompound PFc2Ph was eluted as the second band by using a 5/1 petroleumether/diethyl ether mixture. It was obtained as an orange yellow solid in35% yield after solvent removal in vacuo. 31 P NMR (81.0 MHz): 8 -30.1. 1 HNMR (200 MHz): 6 7.5 (bm, 2H), 7.23 (bm, 3H), 4.26 (m, 2H), 4.22 (m, 2H),4.14 (m, 2H), 4.05 (s, 10H), 3.91 (m, 2H). Mass spectrum (EI, 150 °C): m/e478 (P+, 100.0), 413 (12.0), 401^(34.4), 335^(12.8), 304 (79.5), 291^(14.2),248 (16.2), 239 (31.7),^216 (25.6),^186 (14.8),^170 (15.3),^157 (12.9),^121(26.4), 56 (29.5). Anal. calcd. for C26H23Fe2P: C, 65.31; H, 4.86. Found: C,11065.42; H, 4.87. The 1 H NMR data agree with those reported in theliterature; the 31 P NMR data were not previously reported.The third band contained an unusual compound Fc'(PFcPh)2. It wasobtained as a yellow solid in 5% yield. 31 13 NMR (81.0 MHz): 8 -30.7. 1 HNMR (200 MHz): 8 7.6-7.36 (bm, 4H), 7.36-7.1 (bm, 6H), 4.4-3.9 (m+s,15+1011), 3.81 (m, 1H). Mass spectrum (EI, 150 ° C): m/e 770 (P+, 100.0),705 (17.2), 507 (14.9), 478 (7.2), 410 (10.8), 399 (7.3), 385 (15.2), 335(11.9), 304 (49.5), 293 (43.8), 262 (9.4), 248 (9.8), 226 (10.5), 186 (15.3),170 (10.9), 121 (21.8), 56 (17.3). Anal. calcd. for C42H36Fe3P2: C, 65.49; H,4.71. Found: C, 65.74; H, 4.89.The fourth band contained the diastereoisomer of Fc'(PFcPh)2. It wasalso yellow in colour and was obtained in 3% yield. 31 P NMR (81.0 MHz): 8 -31.4. 1 H NMR (200 MHz): 8 7.70-6.96 (m, 10H), 4.72 (m, 2H), 4.50 (m, 2H),4.43-4.30 (m, 411), 4.26-3.80 (m, 1611), 3.73 (m, 211). Mass spectrum (El,1 5 0 °C): same as that of the third band. Anal. calcd. for C42H36Fe3P2: C,65.49; H, 4.71. Found: C, 65.79; H, 4.83. This pair of diastereoisomers ofFc'(PFcPh)2 was not previously obtained.3.2.33 Preparation of diethylferrocenylphosphine PEt2Fcn-Butyllithium (12.8 mL, 0.02 mol) was added to ferrocene (5.2 g,0.028 mol) in diethyl ether (30 mL). The solution was stirred at roomtemperature for 60 h after which it was cooled in a dry ice-acetone bath.Et2PC1 (1.9 g, 0.016 mol) was then added dropwise and the mixture wasallowed to warm to room temperature with stirring and left so for 2 h.Following hydrolysis with water (20 mL), the organic layer was isolatedand the solvent removed under reduced pressure. The solid residue waschromatographed on silica. Elution with petroleum ether removed111unreacted ferrocene (10%), and 20/1 petroleum ether/diethyl ether elutedthe desired ligand which was obtained as an orange oil (60%) after solventremoval. 31p NMR (81.0 MHz): 8 -26.1. 1 H NMR (200 MHz): 8 4.28 (m, 2H),4.21 (m, 2H), 4.17 (s, 5H), 1.60 (q, 4H, JH_H=7.1), 1.06 (td, 611, JH -p=14.0,  JH-H=7.1). Mass spectrum (EI, 180 °C): m/e 274 (P+, 40.6), 245 (23.9), 217(100.0), 186 (19.8), 151 (11.2), 121 (90.0), 56 (18.9). Anal. calcd. forCmHi9FeP: C, 61.34; H, 6.99. Found: C, 61.20; H, 6.86.3.2.34 Preparation of ferrocenyldi(iso-propyl)phosphine PFciPr2n-Butyllithium (12.8 mL, 0.02 mol) was added to ferrocene (5.2 g,0.028 mol) in diethyl ether (30 mL). The solution was stirred at roomtemperature for 60 h after which it was cooled in a dry ice-acetone bathand 43 r2PC1 (2.5 g, 0.016 mol) was added dropwise. The mixture wasallowed to warm to room temperature with stirring and left so for 2 hafter which water (20 mL) was added. The organic layer was isolated, thesolvent was removed under reduced pressure, and the solid residue waschromatographed on a silica column. Petroleum ether eluted unreactedferrocene (10%), and 10/1 petroleum ether/diethyl ether eluted thedesired ligand as the second band. Solvent evaporation in vacuo affordedPFciPr2 as a reddish orange oil (60%). 31 P NMR (81.0 MHz): 6 0.6. 1 H NMR(300 MHz): 6 4.51 (m, 2H), 4.36 (m, 2H), 4.06 (s, 5H), 1.62 (m, 2H), 1.26 (dd,6H), 1.11 (dd, 6H). Mass spectrum (EI, 170 °C): m/e 302 (P+, 13.3), 259(9.5), 217 (72.0), 186 (100.0), 121 (96.6), 56 (14.3). Anal. calcd. forCi6H23FeP: C, 63.59; H, 7.67. Found: C, 63.87; H, 7.90.3.2.35 Preparation of n-butylferrocenylphenylphosphine PnB u Fc Ph[250, 315]112n-Butyllithium (12.8 mL, 0.02 mol) was added to ferrocene (2.5 g,0.013 mol) in diethyl ether (20 mL). The solution was stirred at roomtemperature for 20 h after which it was cooled in a dry ice-acetone bathand PhPC12 (1.5 g, 0.008 mol) was added dropwise. The solution was thenallowed to warm to room temperature with stirring and left for 2 h afterwhich water (10 mL) was added. The organic layer was isolated, thesolvent was removed under reduced pressure, and the residue dried invacuo before being chromatographed on a silica column. Elution with 20/1petroleum ether/diethyl ether removed unreacted ferrocene (20%). A 9/1petroleum ether/diethyl ether mixture then eluted the desired ligandwhich was obtained as a yellowish orange solid (25-30%) upon solventremoval. 31 P NMR (121.4 MHz): 8 -27.7. 1 H NMR (200 MHz): 6 7.50-7.30(m,2H), 7.30-7.14 (m, 3H), 4.31-4.21 (m, 3H), 4.11-4.04 (s+m, 5+1H), 1.98-1.77 (m, 2H), 1.56-1.23 (m, 4H), 0.92-0.77 (t, 3H, JH_H=7.0). 13 C NMR (50.3MHz):^8^140.3^(d,^J=9.8),^132.7^(d,^J=19.5),^128.4^(d,^J=15.8),^128.1^(d,J=7.0), 73.2^(d,^J=5.8),^70.4^(d, J=14.6),^69.9^(d, J=3.8),^69.0^(s),^28.7^(d,J=7.4), 28.5 (s), 24.5 (s), 13.9 (s). Mass spectrum (EI, 150 °C): m/e 350 (P+,37.6), 293 (46.2), 216 (100.0),^186^(21.0),^121^(53.2),^77^(17.9),^56^(23.1).Anal. calcd. for C201423FeP: C, 68.58; H, 6.63. Found: C, 68.49; H, 6.53. The 1 HNMR data agree with those in the literature; the 31 P and 13 C NMR datawere not previously recorded.3.2.36 Preparation of di(tert-butyl)ferrocenylphosphine PtBu2F cn-Butyllithium (34.4 mL, 0.055 mol) was added dropwise to ferro-cene (13.3 g, 0.072 mol) in diethyl ether (80 mL). The solution was stirredat room temperature for 60 h, then it was cooled in a dry ice-acetone bathand tB u2PC1 (8.0 g, 0.044 mol) added dropwise. The solution was then113allowed to warm to room temperature with stirring and left so for 2h.After hydrolysis with water (35 mL), the organic layer was isolated,concentrated under reduced pressure and dried in vacuo. The residue wasthen subjected to chromatographic column separation on silica. Elutionwith petroleum ether removed unreacted ferrocene (15%), and 10/1petroleum ether/diethyl ether then eluted the desired product which wasobtained as a darkish orange solid (60%). 31 13 NMR (81.0 MHz): 8 27.8. 1 HNMR (200 MHz): 8 4.41 (m, 1H), 4.28 (m, 2H), 4.20 (m, 1H), 4.11 (s, 5H),1.15 (d, 18H, Jp_H=11.0). Mass spectrum (EI, 120 °C): m/e 330 (Pt, 12.1),306 (7.7), 273 (30.2), 233 (11.4), 217 (100.0), 186 (47.0), 121 (60.7), 56(25.8). Anal. calcd. for C18H27FeP: C, 65.47; H, 8.24. Found: C, 65.11; H, 8.02.3.2.37 Preparation of ferrocene(1,1'-diyl)phenylphosphine Fe(C5H4)2PPh[338-340]n-Butyllithium (6.5 mL, 0.01 mol) and TMEDA (0.6 g, 0.005 mol)were added to ferrocene (0.93 g, 0.005 mol) in diethyl ether (10 mL). Thecolour of the solution changed from orange yellow to red and then toorange as it was stirred overnight. The solution was then cooled in a dryice-acetone bath and PhPC12 (0.8 g, 0.004 mol) was added dropwise. Thesolution was allowed to warm to room temperature with stirring and water(5 mL) was then added. The organic layer was isolated, the solventremoved under reduced pressure, and the solid residue chromatographedon a silica column. Elution with 5/1 petroleum ether/diethyl ether gaveferrocene as the first band (20%), and the second band contained thedesired ferrocenophane ligand. Solvent removal in vacuo affordedFe(C5H4)2PPh as a dark red crystalline solid (25%). 31 P NMR (121.4 MHz): 811.0. 1 H NMR (300 MHz): 6 7.60 (m, 2H), 7.39 (m, 211), 7.31 (m, 111), 4.68114(m, 1H), 4.43 (m, 1H), 4.32 (m, 2H), 4.10 (m, 4H). Mass spectrum (EL180 ° C): m/e 292 (P+, 100.0), 233 (7.3), 226 (46.3), 202 (7.6), 186 (38.5),170 (30.6), 157 (18.1), 133 (10.9), 121 (25.7), 115 (11.1), 81 (8.6), 56(13.5). Anal. calcd. for C16H13FeP: C, 65.79; H, 4.49. Found: C, 65.60; H, 4.60.The spectroscopic data agree with those in the literature.3.2.38 Preparation of ethyldiferrocenylphosphine PEtFc2n-Butyllithium (34.4 mL, 0.055 mol) was added dropwise toferrocene (13.3 g, 0.072 mol) in diethyl ether (80 mL). The solution wasstirred at room temperature for 60 h, then it was cooled in a dry ice-acetone bath and EtPC12 (3.0 g, 0.022 mol) added dropwise. The solutionwas then allowed to warm to room temperature with stirring and left sofor 2 h. After hydrolysis with water (25 mL), the organic layer wasisolated, concentrated under reduced pressure and dried in vacuo. The oilyresidue was then chromatographed on a silica column. Elution withpetroleum ether removed unreacted ferrocene (30%), and 15/1 petroleumether/diethyl ether then eluted the desired ligand in the second band.There were many bands after the PEtFc2 band, and 31 P NMR spectroscopyof the fraction revealed the presence of many products. These were notfurther characterized. PEtFc2 was obtained as an orange solid (15%) aftersolvent evaporation. 31 p NMR (81.0 MHz,): 8 -34.5. 1 H NMR (200 MHz): 64.27-4.15 (bm, 6H), 4.07 (s+m, 10+2H), 1.79 (q, 2H, JH.H=7.7), 1.04 (td, 3H,bi-P= 1 7.5, JH-H=7.7). 13 C NMR (50.3 MHz): 6 78.8 (d, J=19.6), 72.3 (d,J=15.3), 71.1 (d, J=15.0), 68.9 (s), 21.9 (d, J=5.1), 10.9 (d, J=18.8). Massspectrum (EL 120 ° C): m/e 430 (P+, 43.7), 401 (100.0), 333 (13.6), 278(10.5), 241 (10.2), 215 (29.3), 200 (24.7), 186 (34.9), 157 (16.2), 121(30.4), 115 (15.9), 103 (10.8), 75 (15.3), 56 (29.0). Anal. calcd. for C22H23115Fe2P: C, 61.44; H, 5.39. Found: C, 61.52; H, 5.47.3.2.39 Preparation of diferrocenylphenylarsine AsFc2P hn-Butyllithium (32 mL, 0.10 mol) was added to ferrocene (12.5 g,0.065 mol) in diethyl ether (70 mL). The solution was stirred at roomtemperature for 60 h after which it was cooled in a dry ice-acetone bathand PhAsI2 (8.1 g, 0.02 mol) added dropwise. The solution was allowed towarm to room temperature with stirring and left so for 2 h after whichwater (50 mL) was added. The diethyl ether fraction was isolated and thesolvent was removed under reduced pressure. The residue waschromatographed on a silica column. Unreacted ferrocene (20%) was elutedwith petroleum ether. The second band (10%) eluted by using a 3/1petroleum ether/diethyl ether mixture contained an orange solid. Massspectrum (EI, 150°C): m/e 648 (1.1), 602 (0.9), 545 (1.6), 522 (100.0), 445(37.0), 414 (17.7), 370 (12.5), 337 (55.2), 304 (25.6), 260 (29.1), 186(17.3), 121 (14.0), 56 (8.5).The third band proved to be the desired compound AsFc2Ph whichwas isolated as an orange solid (30%). Mass spectrum (EI, 120°C): m/e 522(P+, 57.3), 445 (43.7), 370 (100.0), 337 (10.6), 304 (59.8), 260 (35.8), 248(14.5), 186 (22.4), 121 (35.0), 56 (23.2). Anal. calcd. for C26H23AsFe2: C,59.81; H, 4.44. Found: C, 60.02; H, 4.45.The fourth band contained a yellow solid (15%). Mass spectrum (EI,150°C): m/e 690 (P+, 3.7), 582 (8.0), 504 (58.2), 427 (32.6), 413 (8.3), 337(100.0), 289 (16.9), 270 (36.0), 260 (25.6), 227 (11.3), 214 (44.4), 202(16.0), 197 (15.9), 186 (54.8), 169 (13.0), 152 (18.8), 141 (43.3), 128(18.5), 121 (41.7), 115 (35.0), 78 (16.3), 56 (61.0). It is believed to bei(C5H4AsFcPh)Fe(C5H4AsPh)]20.1163.2.310 Preparation of 1,1'-bis(diphenylphosphino)ferroceneFe(C5H4PPh2)2 [314, 333]n-Butyllithium (27 mL, 0.043 mol) and TMEDA (5.0 g, 0.043 mol)were added to ferrocene (4.0 g, 0.022 mol) in diethyl ether (80 mL). Thesolution was stirred overnight and Ph2PC1 (9.7 g, 0.044 mol) in diethylether (100 mL) was then added through a pressure-equalizing droppingfunnel. The reaction mixture was stirred for another 2 h after which water(50 mL) was added. The organic layer was isolated, concentrated underreduced pressure, and dried over anhydrous MgSO4 overnight. The solutionwas then filtered, and the solvent removed in vacuo. The solid residue waschromatographed on a silica column. A 20/1 petroleum ether/diethyl ethermixture eluted ferrocene (5%). A 5/1 petroleum ether/diethyl ethermixture then eluted the desired compound Fc'(PPh2)2. Solvent evaporationafforded it as an orange crystalline solid (70%). 31 P NMR (121.4 MHz): 8 -17.5. 1 H NMR (200 MHz): 8 7.50-7.10 (bm, 20H), 4.28 (m, 4H), 4.01 (m, 4H).Anal. calcd. for C34H28FeP2: C, 73.67; H, 5.06. Found: C, 73.40; H, 4.86. Thespectroscopic data agree with those in the literature.3.2.311 Preparation of 1,1'-bis(di-iso-propylphosphino)ferroceneFe(C5H4iPr2)2 [341, 342]n-Butyllithium (27 mL, 0.043 mol) and TMEDA (5.0 g, 0.043 mol)were added to ferrocene (4.0 g, 0.022 mol) in diethyl ether (80 mL). Thesolution was stirred overnight and iPr2PC1 (6.8 g, 0.044 mol) in diethylether (100 mL) was then added dropwise through a pressure-equalizingdropping funnel. The mixture was stirred for another 2 h after whichwater (50 mL) was added. The organic layer was isolated, concentratedunder reduced pressure, and dried over anhydrous MgSO4 overnight. The117solution was then filtered, and the solvent was removed in vacuo. The solidresidue was applied to a silica chromatographic column. Elution with 20/1petroleum ether/diethyl ether removed unreacted ferrocene (5%). A 5/1petroleum ether/diethyl ether mixture then eluted the desired compoundFc'(PiPr2)2. Solvent removal in vacuo afforded it as an orange crystallinesolid (80%). 31p NMR (121.4 MHz): 8 0.1. 1 }1 NMR (300 MHz): 6 4.20 (m, 4H),4.11 (m, 4H), 1.85 (m, 4H), 1.00 (dd, 24H). Mass spectrum (EI, 150°C): m/e418 (P+,^21.7), 391^(5.0), 375^(100.0), 334^(21.5), 318^(16.2), 289 (20.3),269 (13.2),^157 (14.0), 246 (28.0), 225 (18.4),^217 (17.8),^186 (20.1),^152(10.9), 121 (27.0), 56 (24.3). Anal. calcd. for C22H36FeP2: C, 63.17; H, 8.67.Found: C, 63.30; H, 8.75. The spectroscopic data agree with those in theliterature.3.2.312 Preparation of 1,1'-bis(diethylphosphino)ferrocene Fe(C5H4PEt2)2n-Butyllithium (10.0 mL, 16.0 mmol) and TMEDA (1.2 mL, 8.0 mmol)were added to ferrocene (1.5 g, 8.0 mmol) in diethyl ether (45 mL) and thereaction mixture was stirred overnight. A solution of Et2PC1 (2.0 g, 16.0mmol) in diethyl ether (80 mL) was added dropwise via a pressure-equalizing dropping funnel and the orange solution turned to pale yellow.After another 2 h of stirring, the mixture was hydrolyzed with H2O (10mL) and the organic layer separated. The solvent was removed underreduced pressure and the residue was chromatographed on silica. Elutionwith petroleum ether gave ferrocene (10%). The second yellow band (15%)eluted with 10/1 petroleum ether/diethyl ether was identified as PEt2F cby TLC, 1 H, and 31 P NMR spectroscopy. The third band proved to be thedesired ligand Fc'(PEt2)2 which was obtained as an orange oil (55%). 31 PNMR (81.0 MHz): 6 -20.9. 1 H NMR (200 MHz): 6 4.53 (m, 2H), 4.28 (m, 2H),1184.20 (m, 4H), 2.13 (m, 4H), 1.22 (m, 6H). Anal. calcd. for C18H28FeP2: C,59.69; H, 7.79. Found: C, 59.07; H, 7.51.3.2.313 Preparation of (3-diethylphosphinoferroceno)diphenylphosphine(1-PPh2-3-PEt2-05H3)Fe(C51 -15)n-Butyllithium (4.6 mL, 7.4 mmol) was added to PFcPh2 (2.8 g, 7.5mmol) in diethyl ether (15 mL) and the solution was stirred at roomtemperature for 60 h. The yellow solution was cooled in a dry ice-acetonebath and Et2PC1 (1.0 g, 8.0 mmol) was added slowly. The reaction mixturewas maintained at low temperature for 2 h and then allowed to warm toroom temperature. After a further 2 h of stirring, the solution washydrolyzed with H2O (10 mL), and the organic layer isolated. The solventwas removed under reduced pressure and the residue waschromatographed on silica with 4/1 petroleum ether/CH2C12 as eluent. Thefirst band gave unreacted ligand PFcPh2 (1.8 g, 64%) identified by TLC, 1 H,and 31 P NMR spectroscopy. The second band proved to be (1-PPh2-3-PEt2-C5H3)Fe(C5H5) and it was obtained as a dark orange solid (15%). 31 P NMR(81.0 MHz): 8 -17.1, -26.5, J<1. 1 11 NMR (200 MHz): 8 7.35-7.10 (m, 1011),4.28 (m, 1H), 4.07 (m, 1H), 3.96 (m+s, 1+5H), 1.50 (bm, 4H), 0.95 (bm, 6H).Mass spectrum (EL 150°C): m/e 458 (Pt, 74.9), 429 (58.6), 401^(76.1), 370(2.9), 335 (3.4), 323 (2.4), 306 (2.3), 293 (13.8), 244 (13.3), 216 (52.5), 183(26.5), 170^(27.6),^121 (33.1), 77^(16.0), 69^(18.3), 56^(47.1), 28^(100.0).Anal. calcd. for C26H28FeP2: C, 68.14; H, 6.16. Found: C, 68.32; H, 6.27.3.2.314 Preparation of ferrocenylphenylsulfide SFcPh [343]n-Butyllithium^(6.4^mL,^0.01^mol)^was^added^to^ferrocene^(2.6^g,0.014 mol) in diethyl ether (20 mL). The solution was stirred at room119temperature for 60 h after which it was cooled in a dry ice-acetone bathand Ph2S2 (1.75 g, 0.008 mol) was added dropwise. The solution wasallowed to warm to room temperature with stirring and left so for 2 hafter which water (10 mL) was added. The organic layer was isolated, thesolvent was removed under reduced pressure, and the residue was appliedto a silica chromatographic column. Elution with petroleum ether removedunreacted ferrocene (15%). A 3/1 petroleum ether/diethyl ether mixturethen eluted the desired ligand SFcPh which was obtained as an orangesolid (55%). 1 11 NMR (200 MHz): 8 7.20-6.96 (m, 5H), 4.38 (t, 2H), 4.31 (t,211), 4.23 (s, 511). Mass spectrum (EI, 120°C): m/e 294 (P+, 100.0), 228(31.9), 217 (7.8), 202 (5.0), 184 (6.6), 173 (12.5), 141 (15.0), 129 (21.9),121 (17.1), 115 (9.7), 56 (21.0). Anal. calcd. for C16H14FeS: C, 65.32; H, 4.80.Found: C, 65.39; H, 4.91. The third band contained a bidentate ligandFc'(SPh)2 (10%) identified by TLC and mass spectrometry. The 1 H NMR dataagree with those in the literature.3.2.315 Preparation of 1,1'-bis(phenylthio)ferrocene Fe(C5H4SPh)2 [347]n-Butyllithium (5.4 mL, 8.6 mmol) and TMEDA (1.0 g, 8.6 mmol)were added to ferrocene (0.8 g, 4.4 mmol) in diethyl ether (20 mL). Thereaction mixture was stirred overnight and PhSSPh (1.9 g, 8.7 mmol) indiethyl ether (10 mL) was added dropwise. The mixture was stirred foranother 2 h and then hydrolyzed with H2O (10 mL). The organic layer wasisolated, the solvent was removed by using rotary evaporator, and theresidue was chromatographed on silica. Petroleum ether eluted ferrocene(10%), and 5/1 petroleum ether/diethyl ether then eluted the desiredcompound Fc'(SPh)2 as an orange solid (75%). Mass spectrum (EI, 120°C):m/e 402 (P+, 100.0), 325 (1.4), 306 (5.0), 293 (5.8), 260 (2.2), 229 (8.0),120216 (8.1), 173 (11.7), 141 (9.4), 115 (5.9), 56 (5.5). Anal. calcd. forC22HigFeS2: C, 65.67; H, 4.51. Found: C, 65.22; H, 4.27.3.2.316 Preparation of 1,1'-bis(methylthio)ferrocene Fe(C5H4SMe)2 [347]n-Butyllithium (5.4 mL, 8.6 mmol) and TMEDA (1.0 g, 8.6 mmol)were added to ferrocene (0.80 g, 4.4 mmol) in diethyl ether (20 mL). Themixture was stirred overnight and MeSSMe (0.82 g, 8.7 mmol) in diethylether (10 mL) was added dropwise. The mixture was stirred for another 2h and then hydrolyzed with H2O (10 mL). The organic layer was isolatedand the solvent was removed by using rotary evaporator. The residue waschromatographed on silica. Petroleum ether eluted ferrocene (15%), and5/1 petroleum ether/diethyl ether then eluted the desired compoundFc'(SMe)2 as an orange oil (55%). 1 H NMR (200 MHz): 8 4.27 (s, 4H), 4.18 (s,4H), 2.29 (s, 6H). Mass spectrum (EI, 120°C): m/e 278 (Pt, 100.0), 263(18.5), 230 (14.3), 199 (42.4), 185 (18.5), 167 (17.7), 152 (15.3), 121(21.5), 56 (16.2). Anal. calcd. for C12H14FeS2: C, 51.81; H, 5.07. Found: C,51.25; H, 5.01. The 1 H NMR data agree with those in the literature.3.2.317 Preparation of diferrocenyldisulfide FcSSFcn-Butyllithium (32 mL, 0.05 mol) was added to ferrocene (13 g, 0.07mol) in diethyl ether (75 mL) and the solution was left stirring at roomtemperature for 60 h after which sulfur (1.28 g, 0.04 mol) was then added.The reaction was exothermic and the solution changed from yellow to darkorange. The mixture was refluxed for another 2 h and was allowed to coolto room temperature. After hydrolysis with H2O (50 mL) the dark redorganic layer was separated and solvent removed under reduced pressure.The yellow residue was chromatographed on silica with 5/1 petroleum121ether/CH2C12 as eluent. The first orange band gave ferrocene (15%). Thesecond band proved to be Fc2S2 (25%). The third band proved to be(C5H4SSFc)Fe(C5H4SFc) (10%), and the fourth yellow band proved to be [31-ferrocenophane Fe(C5H4S)2S (15%).Fc2S2, yellow solid. 1 H NMR (200 MHz): 8 4.35 (m, 4H), 4.20 (m, 4H),4.03 (s, 10H). 13 C NMR (75.4 MHz): 8 73.9 (s), 70.4 (s), 69.6 (s, weak), 69.5(s, C5H5). Mass spectrum (EI, 120°C): m/e 434 (Pt, 16.8), 402 (1.1), 338(9.2), 304 (3.3), 272 (17.3), 217 (100.0), 186 (25.9), 171 (10.9), 152 (41.8),121 (59.0), 97 (24.5), 56 (82.1). Anal. calcd. for C201-118Fe2S2: C, 55.33; H,4.18. Found: C, 55.47; H, 4.30.(C5H4SSFc)Fe(C5H4SFc), orange solid. Mass spectrum (EL 120°C): m/e650^(P+, 2.0), 618 (2.3), 434^(26.4), 402^(8.0),^368^(5.0), 336 (9.0), 304(22.0),^272^(27.3), 218 (100.0),^186 (35.6),^152^(45.1), 121 (36.8), 97(23.9), 56 (54.6). Anal calcd. for C301 -126Fe3S3: C, 55.41; H, 4.03. Found: C,55.69; H, 4.28.Fe(C5H4S)2S, orange solid. 1 H NMR (200 MHz): 8 4.52 (m, 2H), 4.41 (m,2H), 4.36 (m, 211), 3.82 (m, 2H). Mass spectrum (El, 190°C): m/e 280 (P+,100.0), 246 (5.8), 216 (20.5), 184 (87.4), 159 (15.5), 152 (14.3), 140 (14.2),100 (34.9), 96 (52.9), 70 (20.5), 64 (14.6), 56 (11.0). Anal. calcd. forC 1 ofIgFeS3: C, 42.87; H, 2.88. Found: C, 42.77; H, 2.95. The 1 H NMR dataagree with those in the literature.3.2.318 Preparation of diferrocenylsulfide SFc2 [343, 348]n-Butyllithium (1.6 mL, 2.5 mmol) was added to ferrocene (0.65 g,3.5 mmol) in diethyl ether (10 mL). The solution was stirred at roomtemperature for 60 h after which a solution of Fc2S2 (0.87 g, 2.0 mmol) indiethyl ether (2 mL) was added dropwise. After an additional hour of122stirring, the reaction mixture was hydrolyzed with water (10 mL). Theorganic layer was isolated, evaporated, and the solid residue waschromatographed on a silica column. Petroleum ether eluted unreactedferrocene, and 5/1 petroleum ether/diethyl ether afforded the desiredproduct as an orange solid (60%). 1 11 NMR (200 MHz): 8 4.4 (bm, 2H), 4.29(s, 10H), 4.25 (bm, 6H). Mass spectrum (EI, 180°C): m/e 402 (P+, 100.0),336 (9.3), 304 (30.6), 272 (33.1), 217 (11.0), 201 (21.8), 186 (15.3), 144(17.3), 121 (28.0), 96 (24.4), 70 (14.2), 56 (41.6). Anal. calcd. forC2oH18Fe2S: C, 59.74; H, 4.51. Found: C, 60.01; H, 4.62. The 1 H NMR dataagree with those in the literature.3.2.319 Preparation of diferrocenylphenylphosphine sulfide S=PFc2P hDiferrocenylphenylphosphine (0.4 g, 0.84 mmol) and S8 (0.026 g, 0.1mmol) in diethyl ether (15 mL) was stirred for 2 h, and the reactionsolvent was removed in vacuo. The residual yellow powder gavesatisfactory analytical and spectroscopic results without any furtherpurification. 31 P NMR (81.0 MHz): 8 39.2. 1 H NMR (200 MHz): 8 8.0-7.8 (bm,2H), 7.45-7.30 (m, 3H), 4.46 (m, 2H), 4.37 (m, 2H), 4.33 (m, 211), 4.20 (m,2H), 4.11 (s, 10H). Mass spectrum (EI, 150°C): m/e 510 (13+, 100.0), 445(18.7), 433 (32.8), 325 (25.3), 248 (57.2), 186 (20.7), 121 (16.4), 77 (13.2),56 (12.4). Anal. calcd. for C26H23Fe2PS: C, 61.21; H, 4.54. Found: C, 60.98; H,4.60.3.2.320 Preparation of triferrocenylstibine SbFc3n-Butyllithium (32 mL, 0.05 mol) was added to ferrocene (13 g, 0.07mol) in diethyl ether (80 mL). The mixture was stirred at roomtemperature for 60 h after which it was cooled in a dry ice-acetone bath123and SbC13 (3.0 g, 0.013 mol) was added dropwise via a syringe. Thereaction mixture was allowed to warm to room temperature and leftstirring for 2 h after which H2O (20 mL) was added. The organic layer wasseparated, the solvent removed under reduced pressure, and the residuewas chromatographed on a silica column. Elution with petroleum etherremoved ferrocene (30%). Elution with 5/1 petroleum ether/diethyl ethergave a complex mixture which was re-chromatographed on silica with 5/1petroleum ether/CH2C12 as eluent. The third band afforded SbFc3 as anorange crystalline solid in 15% yield. 1 H NMR (200 MHz): 8 4.25 (t, 6H),4.08 (t, 6H), 3.99 (s, 15H). Mass spectrum (DCI, NH3): m/e 676 (P+, 28.7),491 (100.0), 370 (15.8), 338 (10.2), 304 (59.4), 249 (15.1), 187 (90.6), 138(15.9), 129 (23.1), 121 (25.0), 60 (65.8). Anal. calcd. for C30H27Fe3Sb: C,53.24; H, 4.02. Found: C, 53.28; H, 4.10.3.3 Preparation of 0s3 Substitution Complexes3.3.1 Preparation of 0s3(CO)11(PFcPh2)Triosmium dodecacarbonyl 0s3(C0)12 (450 mg, 0.50 mmol) in CH2C12(80 mL) and MeCN (5 mL) was treated with a solution of Me3NO (38 mg,0.50 mmol) in Me0H (5 mL). The reaction mixture was stirred for 2 h afterwhich the volume was reduced to 50 mL and PFcPh2 (190 mg, 0.50 mmol)was added. After a further 2 h of stirring the solvent was removed invacuo and the solid residue was chromatographed on silica with 4/1petroleum ether/CH2C12 as eluent. The major second band that developedproved to be the desired complex 0s3(CO)11(PFcPh2) which was isolated asan orange solid in 75% yield. 31 P NMR (81.0 MHz): 8 -10.6. 1 H NMR (200124MHz.): 8 7.5-7.2 (bm, 10H), 4.48 (m, 2H), 4.15 (m, 2H), 3.96 (s, 5H). Massspectrum (FAB): m/e 1250 (P+), 1222, 1194, 1166, 1138, 1110, 1082,1054, 1026, 998, 970, 951, 940 (base peak), 890, 874, 862. Anal. calcd. forC33H19FeO11Os3P: C, 31.74; H, 1.53. Found: C, 31.81; H, 1.70.3.3.2 Preparation of 0s3(CO)10(PFcPh2)2Triosmium dodecacarbonyl 0s3(CO)12 (450 mg, 0.50 mmol) in CH2C12(80 mL) and MeCN (5 mL) was treated with a solution of Me3NO (75 mg,1.0 mmol) in Me0H (5 mL). The reaction mixture was stirred for 2 h andPFcPh2 (370 mg, 1.0 mmol) was added. After a further 2 h of stirring, thesolvent was removed in vacuo and the residue was chromatographed onsilica by using 4/1 petroleum ether/CH2C12 as eluent. The first bandcontained unreacted 0s3(C0)12. The second band was identified as0s3(C0)11(PFcPh2) (10%) by TLC, 1 H, and 31 P NMR spectroscopy. The majorthird band proved to be the desired complex 0s3(C0)10(PFcPh2)2. Solventevaporation in vacuo afforded it as a reddish orange solid in 65% yield. 31pNMR (81.0 MHz): 8 -12.0 (broad, W1/2=150 Hz). 13 C NMR (50.3 MHz): 8137.7 (d, J=53.7), 132.8 (d, J=11.0), 130.0 (d, J=2.1), 127.7 (d, J=10.5), 82.0(d, J=58.8), 73.8 (d, J=11.5), 71.1 (d, J=8.0), 69.9 (s). 1 H NMR (200 MHz): 87.52-7.24 (m, 20H), 4.47 (m, 4H), 4.16 (m, 4H), 3.95 (s, 10H). Massspectrum (FAB): m/e 1593 (P+, base peak), 1565, 1537, 1509, 1481, 1453,1424, 1405, 1387, 1372, 1359, 1346, 1334, 1316, 1291, 1231, 1165, 1155,1087, 1045, 1025, 1012, 997, 968, 940, 892, 862, 835, 805, 778, 749, 683,672, 645, 617, 590, 559. Anal. calcd. for C54H38Fe20100s3P2: C, 40.76; H,2.41. Found: C, 40.60; H, 2.54.1253.3.3 Preparation of 0s3(CO)11(PFc2Ph)Triosmium dodecacarbonyl 0s3(CO)12 (450 mg, 0.50 mmol) in CH2C12(80 mL) and MeCN (5 mL) was treated with a solution of Me3NO (38 mg,0.50 mmol) in Me0H (5 mL). The reaction mixture was stirred for 2 h afterwhich the volume was reduced to 50 mL and PFc2Ph (240 mg, 0.50 mmol)was added. After a further 2 h of stirring, the solvent was removed invacuo and the solid residue was chromatographed on silica with 4/1petroleum ether/CH2C12 as eluent. The second and only major band provedto be the desired complex 0s3(CO)11(PFc2Ph) which was obtained as anorange solid in 70% yield. 31 P' NMR (81.0 MHz): 6 -22.6. 1 H NMR (200 MHz):8 7.72-7.58 (m, 2H), 7.40-7.24 (m, 3H), 4.53 (m, 4H), 4.34 (m, 2H), 4.20 (s,5H), 4.08 (m, 2H). Mass spectrum (FAB): m/e 1356 (P+), 1328, 1300 (basepeak), 1272, 1244, 1216, 1188, 1160, 1104, 1076, 1055, 1048, 1027, 1020,999. Anal. calcd. for C37H23Fe20110s3P: C, 32.75; H, 1.71. Found: C, 33.04; H,1.94.3.3.4 Preparation of 0s3(C0)10(PFc2Ph)2A solution of 0s3(CO)12 (362 mg, 0.40 mmol) in CH2C12 (50 mL) andMeCN (5 mL) was treated with Me3NO (60 mg, 0.80 mmol) and the solutionwas stirred for 5 h after which the ligand PFc2Ph (382 mg, 0.80 mmol) wasadded. The reaction was continued for 10 h. The solvent was removed invacuo and the residue was chromatographed on silica with 4/1 petroleumether/CH2C12 as eluent. The first band contained small amount of 0s3(CO)12.The second band contained 0s3(CO)11(PFc2Ph) (5%) identified by TLC, 31p,and 1 H NMR spectroscopy. The third band contained trace of anunidentified compound. The fourth band proved to be the desired product0s3(C0)10(PFc2Ph)2 which was obtained as an orange crystalline solid126(75%). 31 P NMR (81.0 MHz): 8 -25.4, -29.8 (CDC13); -25.1, -29.7 (C6D6); -24.8,-29.6 (CD3CN). 1 H NMR (200 MHz): 8 7.83-7.62 (m, 2H), 7.46-7.14 (m, 8H),4.55 (m, 41-1), 4.47 (m, 41-1), 4.42 (m, 21-1), 4.35-4.13 (s+s+m, 10+10+4H), 4.05(m, 2H). Mass spectrum (FAB): m/e 1806 (P+, base peak), 1778, 1750,1722, 1694, 1666, 1646, 1638, 1618, 1610, 1594, 1582. Anal. calcd. forC62H46Fe4O100s3P2: C, 41.21; H, 2.57. Found: C, 41.21; H, 2.62. Suitablecrystals for X-ray structure analysis were obtained by slow evaporation ofa 3/1 hexanes/CH2C12 solution.3.3.5 Preparation of 0s3(C0)11(PEt2Fc)A solution of 0s3(CO)12 (454 mg, 0.50 mmol) in CH2C12 (40 mL) andMeCN (10 mL) was treated with Me3N0.2H20 (56 mg, 0.50 mmol) in Me0H(5. mL). After stirring for 2 h, PEt2Fc (137 mg, 0.50 mmol) in CH2C12 (5 mL)was added and the reaction was continued for another 2 h. The solventwas then removed in vacuo and the residue was chromatographed on silicawith 3/1 petroleum ether/CH2Cl2 as eluent. The first band was unreacted0s3(C0)12 (5%). The second band contained the desired complex0s3(C0)11(PEt2Fc) (70%). The third, fourth, and fifth bands were isolated in5%, 5%, and 10% yields.0s3(C0)11(PEt2Fc), reddish orange solid. 31P NMR (81.0 MHz): 8 -17.0.1 H NMR (200 MHz): 8 4.52 (m, 2H), 4.28 (m+s, 2+5H), 2.50-2.10 (bm, 4H),1.14 (td, 6H, JH.p=19.0, JH_H=8.0). Mass spectrum (FAB): m/e 1152 (P+,base peak), 1124, 1096, 1068, 1040, 1012, 984, 956, 928, 900, 884, 872,855, 841, 826, 814. Anal. calcd. for C25H19FeO11Os3P: C, 26.05; H, 1.66.Found: C, 26.27; H, 1.73.The third band, orange solid. 31 P NMR (81.0 MHz): 8 4.0. 1 H NMR (200127MHz): 8 4.65 (m, 2H), 4.36 (m, 4H), 4.13 (m, 1H), 4.07 (m, 1H), 2.25 (bm,4H), 1.37 (m, 6H).The fourth band, orange solid. 31p NMR (81.0 MHz): 6 -17.1. 1 H NMR(200 MHz): 6 4.65 (m, 1H), 4.47 (m, 2H), 4.26 (s+m, 5+1H), 2.22 (bm, 4H),1.08 (td, 6H). Mass spectrum (FAB): m/e 1110 (P+), 1082, 1054, 1026, 970,942 (base peak), 914, 886, 858, 830.The orange complex in the fifth band was identified as theunsymmetrical isomer of 0s3(C0)10(PEt2Fc)2. 31 P NMR (81.0 MHz): 6 -14.8, -19.1, J=42.9. 1 H NMR (200 MHz): 8 4.44 (m, 2H), 4.16 (m, 2H), 4.11 (s, 5H),2.23 (bm, 4H), 1.08 (td, 6H, JH-p=18, JH-H=9). Mass spectrum (FAB): m/e1398 (P+), 1378 (base peak), 1342, 1314, 1286, 1258, 1230, 1202, 1174,1146, 1118, 1090, 1062. Anal. calcd. for C381138Fe20100s3P2: C, 32.63; H,2.74. Found: C, 32.87; H, 2.88.3.3.6 Preparation of 0s3(C0)11(PFc iPr2)A solution of 0s3(CO)12 (302 mg, 0.33 mmol) in CH2Cl2 (60 mL) andMeCN (5 mL) was treated with Me3NO (25 mg, 0.33 mmol). After 2 h ofstirring, PFciPr2 (110 mg, 0.36 mmol) was added and the mixture was leftstirring for 3 h. The solvent was removed in vacuo and the residue waschromatographed on silica with 3/1 petroleum ether/CH2C12 as eluent. Thefirst greenish yellow band contained 0s3(CO)12 (2%) identified by TLC. Thesecond band proved to be the desired compound 0s3(C0)11(PFciPr2) (60%).The third band contained the symmetrical isomer of 0s3(C0)10(PFciPr2)2(6%). The fourth band contained the unsymmetrical isomer of 0s3(C0)10(PFciPr2)2 (10%). The fifth band contained 0s3(C0)9(PFciPr2)3 (15%).0s3(C0)11(PFciPr2), orange solid. 31 P NMR (81.0 MHz): 5 18.7. 1 H NMR128(200 MHz): 5 4.44 (m, 2H), 4.31 (m, 2H), 4.20 (s, 5H), 2.36 (m, 2H), 1.30 (dd,6H), 1.03 (dd, 611). 13 C NMR (50.3 MHz): 8 77.0 (d, J=44.6), 72.2 (d, J=9.0),70.2 (s), 70.0 (d, J=7.1), 30.5 (d, J=31.7), 18.8 (d, J=1.8), 18.5 (d, J=1.8).Mass spectrum (FAB): m/e 1182 (P+), 1154, 1126, 1098 (base peak), 1069,1041, 1013, 997, 985, 968, 957, 940, 929, 912, 901, 884, 873, 856, 837,828, 800. Anal. calcd. for C27H23Fe0110s3P: C, 27.46; H, 1.96. Found: C,27.81; H, 2.03.The symmetrical isomer of 0s3(C0)10(PFc 1Pr2)2, yellow solid. 31 P NMR(81.0 MHz): 8 14.3. 1 H NMR (200 MHz): 5 4.46 (m, 4H), 4.31 (m, 4H), 4.21 (s,10H), 2.36 (m, 4H), 1.31 (dd, 12H), 1.03 (dd, 12H). Anal. calcd. forC42H46Fe20100s3P2: C, 34.67; H, 3.19. Found: C, 35.03; H, 3.37.The unsymmetrical isomer of 0s3(C0)10(PFciPr2)2, pink solid. 31 P NMR(81.0 MHz): 8 8.9 (broad, W112=180 Hz). 1 H NMR (200 MHz): 8 4.47 (m, 4H),4.33 (m, 4H), 4.18 (s, 10H), 2.45 (m, 4H), 1.32 (dd, 12H), 1.07 (dd, 12H). 13 CNMR (50.3 MHz): 5 78.7 (d, J=41.8), 72.3 (d, J=8.8), 70.1 (s), 69.7 (d, J=7.0),31.4 (d, J=30.0), 18.9 (d, J=2.2), 18.6 (d, J=2.1). Anal. calcd. for C42H46Fe2010Os3P2: C, 34.67; H, 3.19. Found: C, 34.88; H, 3.23.0s3(C0)9(PFciPr2)3, orange solid. 31 P NMR (81.0 MHz): 8 4.0. 1 H NMR(200 MHz): 8 4.36 (m, 6H), 4.17 (m+s, 6+15H), 2.55 (m, 611), 1.40-1.05(complex m, 36H). Anal. calcd. for C57H69Fe3O9Os3P3: C, 39.59; H, 4.02.Found: C, 39.83; H, 3.91.3.3.7 Preparation of 0s3(C0)11(1mBu2Fc)Trimethylamine N-oxide (19 mg, 0.25 mmol) was added to 0s3(C0)12(230 mg, 0.25 mmol) in CH2C12 (30 mL) and MeCN (5 mL). The mixture wasstirred for 0.5 h after which PtB u2Fc (100 mg, 0.30 mmol) was added andthe solution was left stirring for 2 h. The solvent was removed in vacuo129and the residue turned red overnight. Column chromatography on silicawith 3/1 petroleum ether/CH2C12 as eluent afforded a few minor bandsand a major red band which afforded the desired complex0s3(CO )11(PtBu2Fc) as a red solid in 65% yield after solvent evaporation. 31 PNMR (121.4 MHz): 6 43.6. 1 H NMR (300 MHz): 8 4.58 (m, 2H), 4.55 (m, 2H),4.28 (s, 5H), 1.39 (d, 18H, J=13.6). Mass spectrum (FAB): m/e 1208 (P+),1094, 1066, 1038, 1010, 982, 954, 926, 898, 870 (base peak), 842. Anal.calcd. for C29H27Fe0110s3P: C, 28.81; H, 2.25. Found: C, 28.98; H, 2.42.3.3.8 Preparation of 0s3(C0)11(PEtFc2)A solution of 0s3(C0)12 (272 mg, 0.30 mmol) in CH2C12 (50 mL) withMeCN (5 mL) was treated with Me3NO (23 mg, 0.30 mmol). After stirringfor 20 min, PEtFc2 (129 mg, 0.30 mmol) was added and the colour of thesolution changed from yellowish orange to pale yellow. The reaction wascontinued for 2 h after which the solvent was removed in vacuo and theresidue was chromatographed on silica with 3/1 petroleum ether/CH2C12 aseluent. The first band contained the desired product 0s3(C0)11(PEtFc2) asan orange solid (50%). 31 P NMR (81.0 MHz): 8 -21.8. 1 H NMR (200 MHz): 64.46 (m, 2H), 4.42 (m, 2H), 4.33 (m, 2H), 4.26 (m, 2H), 4.25 (s, 10H), 2.65(q, 1H, JH.H=7.8), 2.60 (q, 1H, JH.H=7.8), 1.20 (td, 3H, Jp_H=19.6, JH.H=7.8).13 C NMR (50.3 MHz): 6 82.3 (d, J=57.8), 72.1 (d, J=16.4), 71.1 (d, J=13.6),69.7 (s), 30.7 (d, J=41.3), 9.8 (d, J=6.4). Mass spectrum (FAB): m/e 1308(P+, base peak), 1252, 1224, 1196, 1168, 1140, 1112, 1084, 1056, 972.Anal. calcd. for C33H23Fe2O11Os3P: C, 30.28; H, 1.77. Found: C, 30.41; H, 1.85.The second band contained orange 0s3(C0)10(PEtFc2)2 (15%). Massspectrum (FAB): m/e 1710 (13+, base peak), 1310. Anal. calcd. for C54H46Fe4O10Os3P2: C, 37.91; H, 2.71. Found: C, 38.10; H, 2.86.130•.3.9 Preparation of 0s3(C0)10[Fc'(P 1Pr2)2] and [0s3(C0)11}2[Fe(13113r2)2]A solution of 0s3(C0)12 (453 mg, 0.50 mmol) and Fe(PiPr2)2 (210 mg,0.50 mmol) in toluene (100 mL) was refluxed for 4 h. The solvent was thenremoved under reduced pressure, and the residue was chromatographedon silica with 3/1 petroleum ether/CH2C12 as eluent. The first band wasidentified as [0s3(C0)11)2[Fc'(131Pr2)2] (20%) and the second major bandcontained complex 0s3(C0)10[Fc'(P iPr2)2] (70%).[0s3(C0)11)2[Fe(PiPr2)2], yellow solid. 31 P NMR (121.4 MHz): 6 14.8. 1 HNMR (200 MHz): 6 4.62 (m, 4H), 4.35 (m, 4H), 2.36 (m, 4H), 1.20 (dd, 12H),1.02 (dd, 12H). Mass spectrum (FAB): m/e 2174 (P+), 2148 (base peak),1182, 1061, 1003, 975, 947, 919. Anal. calcd. for C44H36FeO22Os6P2: C,24.29; H, 1.67. Found: C, 24.08; H, 1.59.0s3(C0)10[Fe(P iPr2)2], orange solid. 31 P NMR (121.4 MHz): 6 7.3. 1 HNMR (200 MHz): 8 4.3 (m+m, 4+4H), 2.42 (m, 4H), 1.08 (dd, 24H). Massspectrum (FAB): m/e^1268 (13+, base peak), 1242, 1214, 1186,^1172, 1158,1144,^1130,^1102,^1088,^1074,^1060,^1046,^1032, 1018, 1004,^990, 976,948, 905. Anal. calcd. for C32H36Fe0100s3P2: C, 30.88; H, 2.86. Found: C,30.49; H, 2.84.3.4 Preparation of Ru3 Substitution ComplexesThe preparation of the Ru3 substitution complexes of PFcPh2 andPFc2Ph followed the literature procedures with slight modifications [250,315]. The 1 H NMR spectroscopic data for the mono- and tri-substitutedcomplexes (Ru3(C0)111. and Ru3(CO)9L3, L=PFcPh2 or PFc2Ph) agree reason-13 1ably well with those in the literature; the 31 P NMR spectra for all thesecomplexes were not previously recorded. The 1 H NMR data for thedisubstituted complexes Ru3(CO)10L2 (L=PFcPh2 or PFc2Ph, the symmetricaland the unsymmetrical isomer) did not agree with those in the literature.3.4.1 Preparation of Ru3(CO)11(PFcPh2) [250, 315]A stirred solution of Ru3(CO)12 (260 mg, 0.41 mmol) and PFcPh2 (150mg, 0.41 mmol) in THF (40 mL) was treated with 10 drops of purple BPKsolution. After 20 min the reaction solvent was removed in vacuo, and theresidue was chromatographed on silica with petroleum ether as eluent. Thefirst band proved to be the desired compound Ru3(CO)1 i(PFcPh2) whichwas obtained as an orange solid (80%). 31 P NMR (121.4 MHz): 8 27.3. 1 HNMR (300 MHz): 5 7.60-7.35 (m, 10H), 4.52 (m, 2H), 4.22 (m, 2H), 3.97 (s,5H). Mass spectrum (FAB): m/e 983 (P+), 898, 871, 843, 814, 786, 732,706, 685 (base peak), 629, 592. Anal. calcd. for C331-119Fe0 1 1PRu3; C, 40.38;H, 1.95. Found: C, 40.68; H, 1.99.A 10/1 petroleum ether/diethyl ether mixture eluted the secondband. Mass spectrum (FAB): m/e 1000, 995, 950, 915, 889, 862, 836, 820,805, 717, 699.3.4.2 Preparation of Ru3(C0)10(PFcPh2)2 [250, 315]A stirred solution of Ru3(CO)12 (200 mg, 0.31 mmol) and PFcPh2 (230mg, 0.62 mmol) in THF (40 mL) was treated with 10 drops of purple BPKsolution. After 2 h the reaction solvent was removed in vacuo, and theresidue was chromatographed on silica with 2/1 petroleum ether/CH2C12 aseluent. The first orange band contained Ru3(CO)11(PFcPh2) (15%) identifiedby TLC and 31 P NMR spectroscopy.132The second band contained the symmetrical isomer of Ru3(CO)1(PFcPh2)2 (40%) as a pink red solid. 31P NMR (121.4 MHz): 6 26.9. 1 H NMR(300 MHz): 6 7.75-7.35 (m, 20H), 4.42 (m, 4H), 4.19 (m, 4H), 3.95 (s, 10H).Mass spectrum (FAB): m/e 1325 (P+), 1269, 1241, 1213, 1185, 1156, 1128(base peak), 1100, 1072, 994, 938, 859. Anal. calcd. for C54H38Fe2O10P2Ru3:C, 49.00; H, 2.89. Found: C, 49.24; H, 3.00.The third band contained the unsymmetrical isomer ofRu3(C0)10(PFcPh2)2 (20%) as a purple solid. 31 P NMR (121.4 MHz): 6 24.2,21.6. 1 H NMR (300 MHz): 6 7.55-7.15 (m, 20H), 4.56 (m, 2H), 4.34 (m, 2H),4.13 (m, 4H), 3.91 (s, 5H), 3.88 (s, 5H). Mass spectrum (FAB): m/e 1326(P+), 1298, 1269 (base peak), 1242, 1213, 1185, 1157, 1129, 1100, 1072,938, 859, 830. Anal. calcd. for C54H38Fe2O10P2Ru3: C, 49.00; H, 2.89. Found:C; 49.38; H, 3.12.The fourth band contained dark purple Ru3(CO)9(PFcPh2)3 (10%)identified by TLC and 31 P NMR spectroscopy.3.4.3 Preparation of Ru3(CO)9(PFcPh2)3 [315]A solution of Ru3(CO)12 (200 mg, 0.31 mmol) and PFcPh2 (330 mg,0.89 mmol) in THE (30 mL) was heated for 30 min. The solvent wasremoved in vacuo, and the residue was chromatographed on silica with2/1 petroleum ether/CH2C12 as eluent. The small first and second bandswere not identified. The third orange band contained Ru3(CO)11(PFcPh2)(5%) identified by TLC, 31 P, and 1 H NMR spectroscopy. The fourth red bandcontained the symmetrical isomer of Ru3(C0)10(PFcPh2)2 (15%) identifiedby TLC and 31 P NMR spectroscopy. The fifth band (10%) contained amixture of the symmetrical and unsymmetrical isomers of Ru3(CO)1133(PFcPh2)2 identified by 31 P and 1 H NMR spectroscopy, and micro-analysis.The sixth band contained the desired compound Ru3(CO)9(PFcPh2)3 (60%).The symmetrical isomer of Ru3(CO)10(PFcPh2)2, pink red solid. 31 PNMR (121.4 MHz): 8 26.9.The fifth band, pink solid. 3 1 P NMR (81.0 MHz): 8 26.9; 24.2, 21.6. 1 HNMR (200 MHz): 6 7.75-7.15 (bm), 4.60-4.28 (m), 4.28-4.05 (m), 3.93 (s),3.91 (s), 3.88 (s), 3.86 (m). Anal calcd. for C54H38Fe2010P2Ru3: C, 49.00; H,2.89. Found: C, 48.75; H, 2.98. TLC: 2 spots.Ru3(CO)9(PFcPh2)3, dark purple solid. 31 P NMR (81.0 MHz): 6 28.9. 1 1-1NMR (200 MHz): 6 7.53-7.20 (m, 30H), 4.34 (m, 6H), 4.11 (m, 6H), 3.77 (s,15H). Mass spectrum (FAB): m/e 1665 (P+), 1637, 1157, 1125, 998 (basepeak), 970, 869, 814, 784, 684. Anal. calcd. for C75H57Fe3O9P3Ru3: C, 54.07;H, 3.45. Found: C, 53.81; H, 3.25.3.4.4 Preparation of Ru3(CO)11(PFc2Ph) [250, 315]A stirred solution of Ru3(CO)12 (270 mg, 0.42 mmol) and PFc2Ph (200mg, 0.42 mmol) in THE (40 mL) was treated with 10 drops of purple BPKsolution. After 20 min the reaction solvent was removed in vacuo, and theresidue was chromatographed on silica with 3/1 petroleum ether/CH2C12 aseluent. The first band afforded the desired product Ru3(CO)1 i(PFc2Ph) asan orange solid in 55% yield. 31 P NMR (121.4 MHz): 8 16.0. 1 H NMR (300MHz): 8 7.90-7.60 (m, 2H), 7.45-7.25 (m, 311), 4.52 (m, 211), 4.46 (m, 211),4.34 (m, 211), 4.18 (s, 10H), 4.10 (m, 2H). Mass spectrum (FAB): m/e 1091(P+), 1006, 978, 950, 923, 895, 866, 852, 840, 822, 811, 793 (base peak),781, 766, 737, 714, 680, 608, 580. Anal. calcd. for C37H23Fe2O11PRu3: C,40.79; H, 2.13. Found: C, 41.01; H, 2.23.134The second band contained the unsymmetrical isomer of Ru3(C0)10(PFc2Ph)2 (30%) as a purple red solid. 31 P NMR (121.4 MHz): 8 13.8, 13.4.NMR (300 MHz): 8 7.85-7.70 (m, 4H), 7.40-7.30 (m, 6H), 4.51 (m, 4H),4.44 (m, 4H), 4.36 (m, 4H), 4.19 (s, 20H), 4.11 (m, 4H). Anal. calcd. forC62H46Fe4O10P2Ru3: C, 48.37; H, 3.01. Found: C, 48.03; H, 2.96.3.4.5 Preparation of Ru3(CO)9(PFc2Ph)3 [250, 315]A solution of Ru3(CO)12 (160 mg, 0.25 mmol) and PFc2Ph (360 mg,0.75 mmol) in THF (50 mL) was heated for 20 min. The solvent wasremoved in vacuo, and the residue was chromatographed on silica with2/1 petroleum ether/CH2C12 as eluent. The first orange band containedRu3(C0)11(PFc2Ph) (5%) identified by TLC and 31 P NMR spectroscopy. Thesecond purple red band contained the unsymmetrical isomer of Ru3(CO)1 o(PFc2Ph)2 (30%) identified by TLC and 31 P NMR spectroscopy.The third purple band proved to be the symmetrical isomer ofRu3(C0)10(PFc2Ph)2 (10%). 31P NMR (121.4 MHz): 8 11.8. 1 H NMR (300 MHz):3 7.65-7.50 (m, 4H), 7.45-7.20 (m, 6H), 4.48 (m, 4H), 4.30 (m, 4H), 4.22 (m,4H), 4.15 (m, 4H), 4.02 (s, 20H). Anal. calcd. for C62H46Fe4010P2Ru3: C,48.37; H, 3.01. Found: C, 47.96; H, 3.12.The fourth dark purple band proved to be Ru3(CO)9(PFc2Ph)3 (45%).31p NMR (121.4 MHz): 8 9.6. 1 H NMR (300 MHz): 8 7.6-7.2 (m, 15H), 4.59(m, 6H), 4.42 (m, 6H), 4.24 (m, 6H), 4.07 (s, 30H), 3.99 (m, 6H). Anal. calcd.for C87H69Fe6O9P3Ru3: C, 52.52; H, 3.50. Found: C, 51.88; H, 3.19.3.4.6 Preparation of Ru3(CO)11(PEt2Fc)Triruthenium dodecacarbonyl (320 mg, 0.50 mmol) and PEt2Fc (274mg, 1.0 mmol) in THF (20 mL) was heated for 35 min. TLC revealed the135formation of five products. The solvent was removed in vacuo and theresidue was chromatographed on silica with 3/1 petroleum ether/CH2C12 aseluent. The first orange band contained Ru3(CO)11(PEt2Fc) (50%). 31 P NMR(81.0 MHz): 8 19.6. 1 H NMR (200 MHz): 8 4.44 (m, 2H), 4.21 (m+s, 2+5H),2.24-1.94 (m, 4H), 1.17 (td, 6H, JH..p=17.8, Ju_H=8.0). Mass spectrum (FAB):m/e 886 (P+), 804, 773 (base peak), 746, 717, 690, 662, 634, 617, 605,590, 562. Anal. calcd. for C25H0Fe0 1PRu3: C, 33.91; H, 2.16. Found: C,33.68; H, 2.23.The second pink band contained a complex mixture (15%). 31 P NMR(121.4 MHz): 8 27.1, 22.4, J=42.8; 26.3, 17.9, J=38.7; 44.1. 1 H NMR (300MHz): 8 7.24 (d), 5.29 (d), 4.77 (m), 4.55 (m), 4.50 (m), 4.45-4.20 (bm), 2.9-2.7 (m), 2.35-2.05 (m), 2.00-1.65 (m), 1.50-0.80 (bm). Mass spectrum(FAB): m/e 951 (P+), 866, 839 (base peak), 812, 782, 753.3.4.7 Preparation of Ru3(C0)11(PR iPT2)A solution of Ru3(CO)12 (270 mg, 0.42 mmol) and PFciPr2 (128 mg,0.42 mmol) in THE (40 mL) was treated with 10 drops of purple BPKsolution. After 20 min the reaction solvent was removed in vacuo, and theresidue was chromatographed on silica. Elution with petroleum etherafforded the desired product Ru3(CO)1 i(PFciPr2) in the first band. It wasobtained as an orange solid (55%). 31 P NMR (121.4 MHz): 8 46.2. 1 H NMR(300 MHz): 6 4.52 (m, 2H), 4.37 (m, 2H), 4.28 (s, 511), 2.33 (m, 211), 1.34 (dd,611), 1.11 (dd, 611). Mass spectrum (FAB): m/e 913 (P+), 831, 803 (basepeak), 776, 748, 731, 719, 704, 690, 676, 646, 617, 590, 575, 560, 533,519. Anal. calcd. for C27H23FeO11PRu3: C, 35.50; H, 2.54. Found: C, 35.77; H,2.64.136• The second band contained the symmetrical isomer of Ru3(C0)10(PFciPr2)2 as a purple red solid (30%). 31p NMR (121.4 MHz): 5 41.4. 1 HNMR (300 MHz): 6 4.44 (m, 411), 4.38 (m, 4H), 4.12 (s, 10H), 2.40 (bm, 411),1.23 (dd, 12H). Mass spectrum (FAB): m/e 1189 (1 34. ), 1133, 1118, 1105,1099, 1077 (base peak), 1062, 1049, 1032, 1020, 1005, 993, 965, 949,936, 920, 908. Anal. calcd. for C42H46Fe2010P2Ru3: C, 42.47; H, 3.90. Found:C, 41.99; H, 3.75.3.4.8 Preparation of Ru3(C0)9(PFc iPr2)3A solution of Ru3(C0)12 (200 mg, 0.31 mmol) and PFciPr2 (285 mg,0.94 mmol) in THF (40 mL) was heated for 20 min. The solvent wasremoved in vacuo, and the residue was chromatographed on silica with2/1 petroleum ether/CH2C12 as eluent. The first purple band (50%)contained a mixture of the symmetrical and the unsymmetrical isomers ofRu3(C0)10(PFciPr2)2 in almost equal amounts. 31 P NMR (121.4 MHz): 5 41.4;36.5, 35.2. Anal. calcd. for C42H46Fe2O10P2Ru3: C, 42.47; H, 3.90. Found: C,42.35; H, 3.69.The second band proved to be Ru3(C0)9(PFciPr2)3 which was obtainedas a pink red solid in 35% yield. 31 P NMR (121.4 MHz): 8 40.8. 1 H NMR (300MHz): 8 4.48 (m, 6H), 4.36 (m, 6H), 4.27 (s, 15H), 2.33 (m, 6H), 1.34 (dd,18H), 1.13 (dd, 18H). Anal. calcd. for C57H69Fe3O9P3Ru3: C, 46.83; H, 4.76.Found: C, 46.17; H, 4.61.3.4.9 Preparation of Ru3(CO)11(PtBu2Fc)Triruthenium dodecacarbonyl (256 mg, 0.40 mmol) and PtBu2Fc (265mg, 0.80 mmol) in THF (20 mL) was heated for 30 min after which thesolvent was removed in vacuo. The residue was separated on a silica137chromatographic column with 3/1 petroleum ether/CH2C12 as eluent. Theonly major band that eluted proved to be Ru3(CO)i i(PtBu2Fc) which wasobtained as an orange solid in 60% yield. 31 P NMR (81.0 MHz): 6 76.1. 1 HNMR (200 MHz): 8 4.53 (m, 2H), 4.48 (m, 2H), 4.21 (s, 5H), 1.28 (d, 18H,J=16 Hz). Mass spectrum (FAB): m/e 944 (13+), 829, 802, 774, 746, 717,673, 646, 616, 573, 520, 460 (base peak). Anal. calcd. for C29H27Fe0 1PRu3:C, 36.99; H, 2.89. Found: C, 37.27; H, 3.01.3.4.10 Preparation of Ru3(C0)11(PnBuFcPh)A solution of Ru3(CO)12 (195 mg, 0.30 mmol) and PnBuFcPh (110 mg,0.31 mmol) in THE (20 mL) was treated with 10 drops of purple BPKsolution. After 30 min the reaction solvent was removed in vacuo, and theresidue was chromatographed on silica with 3/1 petroleum ether/CH2C12 aseluent. The second major band contained the desired compound Ru3(CO)1(PnBuFcPh) which was obtained as an orange solid in 75% yield. 31 P NMR(121.4 MHz): 8 17.0. 1 H NMR (300 MHz): 6 7.65-7.50 (m, 2H), 7.35-7.20 (m,3H), 4.38 (m, 2H), 4.32 (m, 2H), 4.15 (s, 5H), 2.12 (m, 2H), 1.73 (m, 2H),1.46 (m, 2H), 1.03 (m, 3H). Mass spectrum (FAB): m/e 962 (Pt), 907, 878(base peak), 850, 823, 795, 767, 739, 710, 693, 666, 638, 610. Anal. calcd.for C311123Fe011PRu3: C, 38.72; II, 2.41. Found: C, 39.06; H, 2.57.3.4.11 Preparation of Ru3(C0)10[Fc t (PPh2)2] [120, 250]The catalyst PPN+Cl - (15 mg) was added to a stirred solution ofRu3(CO)12 (192 mg, 0.30 mmol) and Fc'(PPh2)2 (167 mg, 0.30 mmol) in THE(30 mL). After 30 min the reaction solvent was removed in vacuo and theresidue was chromatographed on silica with 3/1 petroleum ether/CH2C12 aseluent. The small first yellow and second orange bands were not identified.138The third (15%) and fourth (10%) bands were characterized by 1 H NMRspectroscopy and mass spectrometry. The fifth band contained the desiredcompound Ru3(C0)10[Fc t (PPh2)2] which was obtained as a red solid in 60%yield. The latter bands (orange and brownish orange) were not eluted.The third band, pink solid. 1 H NMR (200 MHz): 8 7.94 (m), 7.70 (bm),7.46 (m), 7.31^(m), 6.55 (bm), 6.02 (m), 4.50 (m), 4.40 (m), 4.38 (m), 4.23(s), 4.19 (s), 4.07 (m), 3.96 (s), 3.87 (m), 3.73 (m), 3.69 (m), 2.82 (m). Massspectrum (FAB): m/e 1160 (P+), 1105, 1076,^1050,^1021, 994, 966, 885(base peak), 813. TLC: 2 spots.The fourth band, orange solid. Mass spectrum (FAB): m/e 1177 (P+),1149, 1121, 1093, 1065, 1037, 981 (base peak), 937, 911, 859. TLC: 2spots.Ru3(C0)10[Fc'(PPh2)2], red solid. 31p NMR (81.0 MHz): 6 26.7. 1 H NMR(200 MHz): 6 7.6-7.3 (bm, 20H), 4.40 (m, 4H), 4.30 (m, 4H). Mass spectrum(FAB): m/e 1139 (Pt), 1083 (base peak), 1055, 1026, 998, 970, 944, 915,886, 859. Anal. calcd. for C441-128Fe010P2Ru3: C, 46.45; H, 2.48. Found: C,46.19; H, 2.49. The 1 H NMR data agree with those in the literature; the 3 1 PNMR data were not previously recorded.3.4.12 Preparation of Ru3(C0)10[Fc 1 (PFcPh)2]The catalyst PPN+Cl - (15 mg) was added to a stirred solution ofRu3(CO)12 (192 mg, 0.30 mmol) and Fc'(PFcPh)2 (231 mg, 0.30 mmol) inTHE (25 mL). After 2 h the reaction solvent was removed in vacuo, and theresidue was chromatographed on silica with 3/1 petroleum ether/CH2C12 aseluent. The only major band that developed proved to be the desiredcompound Ru3(C0)10[Fe(PFcPh)2] which was obtained as a red solid in 85%yield. 31 P NMR (81.0 MHz): 6 20.4. 13 C NMR (50.3 MHz): 6 139.6 (d, J=42.5),139130.3 (d, J=9.2), 129.3 (s), 127.6 (d, J=10.0), 81.0 (d, J=47.7), 74.2 (s), 72.1(d, J=7.1), 71.7 (d, J=7.6), 69.8 (d, J=1.6), 69.3 (d, J=7.9), 68.0 (s). Massspectrum (FAB): m/e 1355 (P+), 1299 (base peak), 1271, 1243, 1215, 1187,1158, 1130. Anal. calcd. for C52H36Fe3O10P2Ru3: C, 46.14; H, 2.68. Found: C,46.67; H, 2.75.3.4.13 Preparation of Ru3(C0)10[Fc e (PtBuPh)2]The catalyst PPN+Cl - (25 mg) was added to a stirred solution ofRu3(CO)12 (200 mg, 0.31 mmol) and Fc'(PtBuPh)2 (163 mg, 0.32 mmol) inTHF (40 mL). The colour of the solution changed immediately to dark red.It was left stirring for 30 min, then the solvent was removed in vacuo, andthe residue was chromatographed on silica with 3/1 petroleum ether/CH2C12 as eluent. The first band contained Ru3(CO)12 (5%) identified by TLC.The second major band proved to be the desired compound Ru3(CO)i[Fe(PtBuPh)2] which was obtained as a dark red solid (70%). 31 P NMR(121.4 MHz): 8 46.9. 1 H NMR (300 MHz): 8 8.35-8.10 (bm, 4H), 7.60-7.40(bm, 6H), 4.72 (m, 2H), 4.63 (m, 4H), 4.45 (m, 2H), 0.88 (d, 18H). Massspectrum (FAB): m/e 1097 (P+), 1039, 1011, 983, 955 (base peak), 901,874, 801, 773, 745, 717, 659, 644. Anal. calcd. for C40}136Fe010P2Ru3: C,43.77; H, 3.31. Found: C, 43.28; 11, 3.22.3.4.14 Preparation of Ru3(C0)10[Fc'(P IPr2)2]The catalyst PPN+Cl - (10 mg) was added to a solution of Ru3(CO)1 2(260 mg, 0.40 mmol) and Fc'(PiPr2)2 (170 mg, 0.40 mmol) in THF (20 mL).The colour of the solution changed instantly from orange to dark red, andthe reaction was complete in 30 min as shown by TLC. Solvent removalunder reduced pressure afforded a dark red residue which was chromato-1 4 0graphed on silica with 3/1 petroleum ether/CH2C12 as eluent. The onlymajor band contained the desired product Ru3(C0)10[Fe(PiPr2)2] which wasobtained as a dark red crystalline solid in 75% yield. 31 P NMR (121.4 MHz):6 41.3. 1 H . NMR (300 MHz): 8 4.50 (m, 4H), 4.40 (m, 4H), 2.55-2.30 (m, 4H),1.45-1.10 (m, 24H). Mass spectrum (FAB): m/e 1001 (Pl. ), 973, 945, 917,889 (base peak), 861, 833, 818, 805, 790, 777, 762, 749, 734, 721, 706,693, 678, 661, 650, 629, 589, 562, 549. Anal. calcd. for C32H36Fe0101 3 2Ru3:C, 38.37; H, 3.62. Found: C, 38.40; H, 3.77.3.4.15 Preparation of Ru3(C0)9[Fc 1 (PiPr2)2](PFc2Ph)A solution of Ru3(C0)10[Fe(P iPr2)2] (200 mg, 0.20 mmol) and PFc2Ph(96 mg, 0.20 mmol) in hexanes (50 mL) was refluxed for 3.5 h. TLCrevealed that only one major compound is present. The solvent wasremoved in vacuo and the dark residue was chromatographed on silicawith 1/1 petroleum ether/CH2C12 as eluent. The only major band thatdeveloped proved to be the desired product Ru3(C0)9[Fc'(PiPr2)2](PFc2Ph)which was obtained as a pinkish red solid in —90% yield. 31 P NMR (81.0MHz): 8 37.6 (d, J=15.0), 36.0 (s), 13.9 (d, J=15.0). 1 H NMR (200 MHz): 6 8.02(m, 2H), 7.29 (m, 3H), 4.52 (m, 2H), 4.44 (m, 2H), 4.36 (m, 4H), 4.24 (m,6H), 4.15 (s, 10H), 4.07 (m, 2H), 2.21 (bm, 4H), 1.4-0.8 (very broad, 24H).Anal. calcd. for C57H59Fe3O9P3Ru3: C, 47.16; H, 4.10. Found: C, 47.23; H, 4.17.3.4.16 Preparation of Ru3(C0)91Fc'(PiPr2)21(PEtFc2)A solution of Ru3(C0)10[Fe(P iPr2)2] (200 mg, 0.20 mmol) and PEtFc2(86 mg, 0.20 mmol) in CH2C12 (15 mL) was stirred at room temperature for5 days. TLC indicated that a pink product is present. The solvent wasremoved in vacuo and the residue was chromatographed on silica with 1/1141petroleum ether/CH2C12 as eluent. The first band gave unreactedRu3(C0)10[Fc . (PiPr2)2] (40%). The second band proved to be Ru3(CO)9[Fc'(P iPr2)2](PEtFc2) which was obtained as a dark red solid in 45% yield.31 P NMR (81.0 MHz): 6 37.0 (d, J=13.5), 35.7 (s), 11.8 (d, J=13.5). 1 H NMR(200 MHz): 8 4.56 (m, 2H), 4.48 (m, 2H), 4.36 (m, 2H), 4.32 (m, 2H), 4.26(m, 611), 1.6-0.8 (bm, 27H). Anal. calcd. for C53H59Fe3O9P3Ru3: C, 45.35; H,4.24. Found: C, 45.48; H, 4.31.3.4.17 Preparation of Ru3(C0)11(PEtFc2)A solution of Ru3(CO)12 (130 mg, 0.20 mmol) and PEtFc2 (130 mg,0.30 mmol) in cyclohexane (20 mL) was heated for 5 h. TLC revealed theformation of one product which did not undergo further reaction. Thesolvent was removed in vacuo, and the residue was chromatographed onsilica with 2/1 petroleum ether/CH2C12 as eluent. The only major orangeband that developed proved to be Ru3(CO)1 l(PEtFc2) (65%). 3 1 P NMR (121.4MHz): 6 15.2. 1 H NMR (300 MHz): 6 4.48 (m, 2H), 4.43 (m, 2H), 4.33 (m, 2H),4.18 (s, 10H), 4.12 (m, 2H), 2.51 (m, 2H), 1.34 (m, 3H). Mass spectrum(FAB): m/e 1043 (Pt, base peak), 1015, 987, 959, 931, 902, 874, 846, 819,790, 761, 733. Anal. calcd. for C33H23Fe2011PRu3: C, 38.06; H, 2.23. Found: C,38.25; H, 2.08.3.5 Pyrolysis of 0s3 Complexes3.5.1 Pyrolysis of 0s3(C0)11(PFcPh2)(a) in octane for 3 h142A solution of 0s3(C0)11(PFcPh2) (60 mg, 0.048 mmol) in octane (25mL) was refluxed for 3 h. 31 P NMR spectroscopy revealed one majorresonance at 207.3 and three small ones at 195.9, 65.4, and -6.0 ppm. Thesolvent was removed in vacuo and the residue was chromatographed onsilica with 4/1 petroleum ether/ CH2C12 as eluent. The first greenish yellowband contained 0s3(C0)12 (2%). The second band contained complex (239)(80%). The third band contained complex (240) (3%). The fourth band (1%)contained trace of a complex identified only by mass spectrometry. Thefifth band (2%) contained a complex mixture including complex (245)(Section 3.5.3) as judged by TLC and hydride resonances in the 1 H NMRspectrum. Crystals of (239) suitable for X-ray structure analysis wereobtained by slow evaporation of the eluted band.(239), red solid. 31 13 NMR (81.0 MHz): 8 207.3. 1 H NMR (300 MHz): 87.63 (m, 2H), 7.12 (m, 2H), 4.63 (m, 2H), 4.54 (m, 2H), 4.26 (s, 5H). Massspectrum (FAB): m/e 1116 (P+, base peak), 1088, 1060, 1032, 1004, 976,948, 920, 892, 875, 864. Anal. calcd. for C25H13FeO9Os3P: C, 26.94; H, 1.18.Found: C, 27.16; H, 1.33.(240), dark red solid. 31 P NMR (81.0 MHz): 8 65.4. 1 H NMR (400 MHz):8 7.77 (m, 2H), 7.51 (m, 2H), 4.51 (m, 1H), 4.13 (s, 5H), 4.11 (m, 2H), 3.60(m,^1H).^Mass^spectrum^(FAB):^m/e^1142^(P+,^base peak),^1114,^1086,1058,^1030, 1002, 974, 946, 918, 890, 862.The fourth band, orange solid. Mass spectrum (FAB): m/e 1114 (P+,base peak),^1086, 1058, 1030,^1002, 974, 946, 918, 890, 862.The fifth band, orange solid. 1 H NMR (400 MHz): 8 9.29 (m), 8.22 (m),7.90 (m), 7.65-7.51^(m), 7.47-7.32 (bm), 7.25-7.10 (m), 6.18 (m), 5.18 (m),4.87 (m), 4.80 (m), 4.72 (m), 4.70 (m), 4.63 (m), 4.50 (m), 4.46 (m), 4.33(m), 4.28^(m), 4.22 (m), 4.12 (m), 4.08 (m), 4.04 (m), 4.00 (m), 3.97 (s),1433.75 (m), 3.62 (m), 3.22 (m), 3.03 (m), -11.69 (d, J=6.2), -12.16 (d, J=4.3),(245), -12.51 (s), -12.54 (d, J=11.4), -16.29 (d, J=8.7), -16.86 (d, J=13.4),(245), -17.78 (d, J=17.1), -18.14 (d, J=19.0), -18.43 (d, J=15.0).(b) in octane for 21 hA solution of 0s3(C0)11(PFcPh2) (100 mg, 0.080 mmol) in octane (50mL) was refluxed for 21 h. 31 P NMR spectroscopy revealed a majorresonance at 207.3 and four minor ones at 290.2, 235.0, 166.8, and 125.7ppm. The resonances at 195.9, 65.4, and -6.0 ppm were not observed. Thereaction solvent was removed in vacuo and the residue waschromatographed on silica with 3/1 petroleum ether/CH2C12 as eluent. Thefirst red band contained (239) (65%) identified by TLC, 31 P, and 1 H NMRspectroscopy. The second orange band (2%) contained a mixture of (239)and three other complexes by TLC. The third band (2%) contained amixture of two complexes. The fourth pink band (4%) contained a mixtureof two complexes by TLC. The fifth band (5%) contained a complex mixtureof at least four complounds. The sixth band contained complex (241) (8%).The seventh band (2%) contained a mixture of two complexes. The eighthyellow band contained traces of a mixture of two complexes by TLC.The third band, orange solid. 31 P NMR (121.4 MHz): 6 306.6. TLC: 2spots.The fifth band, dark brown solid. 31p NMR (81.0 MHz): 6 360.2, 357.2,290.2 (major), 264.9, 235.0, 142.1, 125.7 (major). The 1 H NMR (300 MHz)spectrum is very complex with many interesting resonances. TLC: 5 spots.(241), yellow solid. 31 P NMR (121.4 MHz): 6 166.8. 1 1-1 NMR (400MHz): 8 8.97 (m, 2F1), 8.01 (m, 1H), 7.43 (m, 1H), 7.32 (m, 2H), 7.03 (m, 21-1),5.00 (m, 2H), 4.52 (m, 2H), 4.41 (m, 4H), 3.90 (s, 10H). Mass spectrum144(FAB): m/e 2201 (P+), 2145, 2117 (base peak), 2089, 2061, 1720, 1652.The seventh band, dark orange solid. 31 P NMR (81.0 MHz): 6 229.3,43.8. 1 H NMR (200 MHz): 8 7.72 (m), 7.52 (m), 7.40 (m), 5.28 (m), 5.06 (m),4.58-5.35 (m), 4.25 (s), 4.22 (s), 4.12 (s), 3.96 (m), 3.88 (m), 3.82 (s), 3.70(m). TLC: 2 spots.(c) in cyclohexaneA solution of 0s3(C0)11(PFcPh2) (110 mg, 0.090 mmol) in cyclohexane(30 mL) was refluxed for 25 h after which the solvent was removed invacuo. TLC revealed the presence of the starting material (80%), complex(239) (10%), and three other complexes. 31 P NMR spectroscopy revealed amajor resonance at -10.6 ppm due to the starting material, two moderatelystrong resonances at 207.3 and -6.1 ppm due to complexes (239) and (242)respectively, and three very small resonances at 65.4, 13.6, and -17.1 ppm.(d) in heptaneThe reaction mixture from (c) was dried in vacuo and heptane (20mL) was added. This mixture was then refluxed for 5 h after which thesolvent was removed in vacuo. 31 P NMR spectroscopy revealed three majorresonances at -10.6, -6.1, and 207.3 ppm due to the starting material,compounds (242), and (239), respectively. The resonances at 65.4 and -17.1 ppm were also more significant. The solid residue waschromatographed on silica with 4/1 petroleum ether/CH2C12 as eluent. Thefirst red band contained (239) (25%). The second red band (5%) containeda mixture of (240) identified by 1 11 and 31 P NMR spectroscopy and acomplex with a 31 P NMR resonance at -17.1 ppm. The third band containedcomplex (242) (20%). The fourth orange band contained unreacted starting145material (30%) identified by TLC and 31 P NMR spectroscopy. The fifth band(8%) contained a mixture of complexes (243) and (245). The last brownband contained traces of a mixture of two complexes by TLC. Crystals of(242) suitable for X-ray structure determination were obtained from a 3/1hexane/CH2C12 solution.(242), orange solid. 3 1 P NMR (121.4 MHz): 6 -6.1. 1 H NMR (300 MHz):6 7.55-7.35 (m, 2H), 7.35-7.20 (m, 3H), 6.75-6.60 (m, 2H), 6.60-6.45 (m,2H), 5.16 (m, 1H), 4.78 (m, 1H), 4.48 (m, 1H), 4.37 (s, 5H), 3.26 (m, 1H), -17.82 (d, 1H, J=17.5). Mass spectrum (FAB): m/e 1194 (P+, base peak),1166, 1138, 1110, 1082, 1060, 1054, 1032, 1026, 998, 970, 942, 920, 892.Anal. calcd. for C31H19Fe090s3P: C, 31.21; H, 1.61. Found: C, 31,35; H, 1.58.(243) and (245), dark orange solid. 31 P NMR (121.4 MHz): 8 13.8,(243); -5.9, (245). 1 H NMR (300 MHz): 3 7.35-7.20 (bm, 10H), 5.15 (m, 2H),4.67 (m, 1H), 4.32 (m, 111), 4.02 (m, 111), 3.20 (m, 1H), 3.01 (m, 111), -12.19(d, 1H, J=4.2), -16.88 (d, 1H, J=13.5), (245); 7.69-7.60 (m, 2H), 7.57-7.52(m, 3H), 7.43 (m, 1H), 7.28 (m, 1H), 7.19-7.11 (m, 2H), 4.71 (m, 1H), 4.60(m, 2H), 4.16 (m, 1H), 3.97 (s, 5H), -12.56 (d, 1H, J=7.8) (243).3.5.2 Pyrolysis of 0s3(C0)9(PFc)(C6H4) (239)A solution of 0s3(C0)9(PFc)(C6114) (239) (60 mg, 0.050 mmol) indecalin (20 mL) was refluxed for 10 h after which the solvent wasremoved in vacuo. TLC revealed the presence of more than ten complexesin the mixture, and 31 P NMR spectroscopy revealed many resonancesbetween 250 and 400 ppm. A detailed analysis gives the following majorresonances:^377.7,^295.7,^J=51.8;^357.6, 328.7, J=47.5; 351.5, 312.3,J=119.8;^306.4,^270.6,^J=43.1;^281.9,^270.1, J=55.5; 289.6, 266.4, J=60.5;340.3, 316.9, J=37.5. No chromatographic separation was carried out.1463.5.3 Pyrolysis of 0s3(C0)10(PFcPh2)2A solution of 0s3(C0)10(PFcPh2)2 (240 mg, 0.15 mmol) in octane (50mL) was refluxed for 5 h. The solvent was removed in vacuo and the residuewas applied to a silica chromatographic column. Elution with 3/1 petroleumether/CH2Cl2 gave more than fifteen bands. The bands after the twelvethwere not eluted. The fifth and eleventh bands contained traces of mixtures.The ninth band (4%) contained complexes (248) and (249). The other bandsin the order of elution contained complexes (239) (5%), (240) (2%), (242)(3%), (244) (5%), (245) (4%), (246) (15%), (247) (20%), (250) (8%), and (251)(25%), respectively. Crystals of (245) and (251) suitable for X-ray structuredeterminations were obtained from 2/1 and 1/1 hexane/CH2C12 solutionsrespectively.(239), red solid. 31 P NMR (81.0 MHz): 6 207.3. 1 H NMR (200 MHz): 67.58 (m, 211), 7.07 (m, 2H), 4.59 (m, 2H), 4.50 (m, 211), 4.22 (s, 511).(240), dark red solid. 31 P NMR (81.0 MHz): 6 65.4. 1 H NMR (200 MHz): 87.76 (m, 2H), 7.50 (m, 2H), 4.61 (m, 1H), 4.13 (s, 5H), 4.08 (m, 2H), 3.58 (m,1H).(242), orange solid. 31p NMR (81.0 MHz): 8 -6.0. 1 H NMR (200 MHz): 87.55-7.35 (m, 211), 7.35-7.20 (m, 3H), 6.75-6.60 (m, 2H), 6.60-6.45 (m, 2H),5,16 (m, 111), 4.78 (m, 111), 4.48 (m, 11-1), 4.37 (s, 5H), 3.26 (m, 1H), -17.82 (d,1H, J=17.7).(244), yellow solid. 31 P NMR (121.4 MHz): 8 21.2. 1 H NMR (300 MHz): 88.16 (m, 2H), 7.68 (m, 2H), 7.58-7.25 (m, 6H), 5.19 (m, 2H), 4.80 (m, 2H),4.32 (m, 2H), 3.31 (m, 2H), -5.43 (d, 111, J=21.8). Mass spectrum (FAB): m/e1220 (P+), 1192 (base peak), 1164, 1136, 1107, 1079, 1050, 1022, 994, 966,938, 860. Anal. calcd. for C321-119Fe0100s3P: C, 31.48; H, 1.57. Found: C, 31.81;H, 1.69.147The fifth band, orange solid. 31 13 NMR (81.0 MHz): 8 -10.6, -17.1. 1 HNMR (400 MHz): 8 9.3, 8.6, 8.2, 7.9-6.9, 4.95, 4.88, 4.70, 4.62, 4.46-4.30, 3.92,3.76, 3.24, -11.69 (d, J=5.98), -12.53 (d, J=18.12), -15.00 (d, J=11.63), -15.10(d, J=8.24). TLC: 3 spots.(245), orange solid. 31 P NMR (81.0 MHz): 8 -6.0. 1 H NMR (200 MHz): 67.30-7.15 (bm, 10H), 5.12 (m, 2H), 4.62 (m, 1H), 4.27 (m, 1H), 3.98 (m, 1H),3.16 (m, 1H), 2.97 (m, 1H), -12.23 (d, 1H, J=4.2), -16.94 (d, 1H, J=13.4). Massspectrum (FAB): m/e 1164 (P+, base peak), 1136, 1108, 1080, 1050, 1024,993, 966, 936, 861. Anal. calcd. for C3oH19Fe080s3P: C, 30.93; 11, 1.64. Found:C, 31.20; H, 1.71.(246), pink solid. 31 P NMR (81.0 MHz): 6 157.7. 1 H NMR (200 MHz): 87.73 (bm, 4H), 7.36 (bm, 6H), 6.60 (bm, 2H), 6.04 (m, 2H), 4.53 (m, 2H), 4.46(m, 2H), 4.34 (m, 2H), 4.27 (s, 10H), 3.99 (m, 2H). Mass spectrum (FAB): m/e1430 (Pt, base peak), 1402, 1374, 1346, 1318, 1290, 1262, 1232, 1153,1087-1078, 1046. Anal. calcd. for C45H32Fe2O7Os3P2: C, 37.82; H, 2.26. Found:C, 38.04; H, 2.35.(247), pink solid. 31 P NMR (202.5 MHz): 6 187.4, 143.8, J=166.1. 1 11NMR (500 MHz): 6 8.03 (q, 2H), 7.81 (q, 2H), 7.60-7.50 (bm, 6H), 7.01 (d, 1H,J=8.0), 6.51 (d, 1H, J=8.0), 6.40 (t, 1H, J=8.0), 6.31 (t, 1H, J=8.0), 4.51 (m, 1H),4.42 (m, 1H), 4.30 (s, 5H), 4.24 (m, 1H), 4.13 (m, 1H), 3.99 (s, 5H), 3.80 (m,1H), 3.78 (m, 1H), 2.76 (m, 1H), 2.30 (m, 1H). Mass spectrum (FAB): m/e1430 (Pt, base peak), 1400, 1371, 1344, 1315, 1289, 1259, 1231, 1153,1087, 1044, 968. Anal. calcd. for C45H32Fe2O7Os3P2: C, 37.82; H, 2.26. Found:C, 37.96; H, 2.47.(248) and (249), yellow solid. 31 P NMR (121.4 MHz): 6 42.3, -13.6(248); 40.8, -12.7 (249). 1 H NMR (500 MHz): 6 7.94 (q, 2H), 7.54 (m, 2H), 7.47(m, 3H), 7.41 (m, 2H), 7.32 (m, 3H), 7.17 (m, 3H), 6.72 (d, 1H), 6.53 (d, 1H),1486.44 (t, 1H), 6.21 (t, 1H), 4.47 (m, 2H), 4.28 (m, 2H), 4.24 (s, 5H), 4.16 (m,2H), 4.05 (s, 5H), 3.98 (m, 1H), 3.94 (m, 1H), -14.17 (dd, 1H, J1=J2=1 2.1)(248); 7.88 (q, 2H), 7.70 (m, 2H), 7.49 (m, 3H), 7.30 (m, 3H), 7.22 (m, 2H),6.92 (m, 3H), 6.82 (tm, 1H), 6.10 (t, 1H), 6.07 (d, 1H), 6.02 (bm, 1H), 4.44 (m,1H), 4.32 (m, 1H), 4.18 (s, 5H), 4.03 (m, 2H), 3.98 (m, 2H), 3.93 (m, 2H), 3.88(s, 5H), -14.20 (dd, 1H, Ji=12.4, J2=11.0) (249).(250), orange solid. 31 p NMR (81.0 MHz): 6 195.8, 0.0. 1 H NMR (200MHz): 8 7.97-7.78 (m, 2H), 7.65-7.48(m, 4H), 7.45-7.30 (m, 4H), 7.12 (bm,2H), 6.18 (bm, 2H), 4.55-4.45 (bm, 4H), 4.35-4.26 (bm, 21-1), 4.24-4.19 (bm,1H), 3.98 (s, 5H), 3.94 (s, 5H). Mass spectrum (FAB): m/e 1458 (P+, basepeak), 1430, 1402, 1374, 1345, 1317, 1289, 1261, 1233, 1155.The eleventh band, pink solid. 31 I3 NMR (81.0 MHz): 8 154.1; 109.0, -24.0; -6.8, -12.4. 1 H NMR (200 MHz): 8 8.2-5.8 (complex), 4.7-2.2 (complex), -7.85 (d, J=9.6), -9.25 (d, J=11.9), -13.91 (d, J=12.5). TLC: 3 spots.(251), orange solid. 31 13 NMR (81.0 MHz): 8 0.1, -2.5, J=15.1. 1 H NMR(400 MHz): 8 7.43-7.37^(m, 1H),^7.37-7.25^(bm, 411), 7.19-7.07^(bm,^311),7.05-6.98^(tm, 1H),^6.94-6.81 (bm,^3H),^6.78-6.71 (tm, 1H),^6.57-6.47^(bm,4H), 6.44-6.38 (tm, 1H), 6.16-6.09 (tm, 1H), 5.14 (m, 1H), 4.68 (m, 1H), 4.51(m, 1H), 4.42 (m, 2H), 4.39 (m, 1H), 4.17 (s, 5H), 3.88 (m, 1H), 3.87 (s, 5H),3.28 (m, 1H), -17.42 (dd, 11-1, J1=17.8, J2=8.8). Mass spectrum (FAB): m/e1536 (Pt, base peak), 1508, 1480, 1452, 1424, 1396, 1368, 1196, 1144,1138, 1070, 1033, 957, 924. Anal. calcd. for C52H38Fe2080s3P2: C, 40.69; H,2.50. Found: C, 40.81; H, 2.54.3.5.4 Pyrolysis of 0s3(CO)11(PFc2Ph)A solution of 0s3(CO)11(PFc2Ph) (200 mg, 0.15 mmol) in octane (80mL) was refluxed for 3 h. TLC showed the presence of more than ten149products. The reaction solvent was removed in vacuo and the residue waschromatographed on a silica column by using 4/1 petroleum ether/CH2C12as eluent. The first band contained 0s3(CO)9 (PFc)C6H4) (239) (8%). Thesecond band (20%) proved to be a novel ferrocyne complex (252). Thethird and fourth bands contained complexes (253) (3%) and (254) (2%)respectively. The fifth band contained small amount of an unidentifiedmixture. The sixth band contained complex (255) (2%). The seventh darkred band contained (240) (4%) identified by 31 P and 1 H NMR spectroscopy.The eighth to fifteenth bands contained complexes (256) (3%), (257) (6%),(258) (5%), (259) (3%), (260) (4%), (261) (10%), (262) (6%), and (263) (5%),respectively. A few very small bands after the fifteenth band were noteluted. Crystals of (252) and (263) suitable for X-ray structure determina-tions were obtained from 3/1 hexane/CH2C12 solutions. Crystals of (261)were obtained by slow evaporation of the eluted band. Crystals of (254),obtained from a 2/1 hexane/CH2C12 solution, await analysis.(239), red solid. 3 1 P NMR (121.4 MHz): 8 207.2. 1 H NMR (400 MHz): 87.62 (m, 2H), 7.11 (m, 2H), 4.62 (m, 2H), 4.55 (m, 2H), 4.26 (s, 5H). Massspectrum (FAB): m/e 1116 (P+, base peak), 1088, 1060, 1032, 1004, 976,948, 920, 892, 875, 864. Anal. calcd. for C25H13FeO9Os3P: C, 26.94; H, 1.18.Found: C, 27.01; H, 1.20.(252), green solid. 31p NMR (121.4 MHz): 8 189.8. 1 H NMR (400 MHz):8 5.04 (dm, 2H), 4.52 (m, 4H), 4.36 (s, 5H), 4.20 (s, 5H), 3.98 (m, 1H). Massspectrum (FAB): m/e 1224 (P1- , base peak), 1196, 1168, 1140, 1112, 1084,1056, 1028, 1015, 1000, 984, 970, 922, 905, 881, 864, 851. Anal. calcd. forC291-117Fe2090s3P: C, 28.48; H, 1.39. Found: C, 28.21; H, 1.27.(253), orange solid. 31 P NMR (121.4 MHz): 8 -24.2. 1 H NMR (400150MHz): 8 8.09 (m, 2H), 7.68 (m, 311), 5.22 (m, 1H), 4.53 (m, 1H), 4.48 (m, 1H),4.44 (m, 1H), 4.33 (m, 1H), 4.30 (m, 2H), 4.27 (m, 1H), 4.02 (m, 1H), 3.92(m, 111), 3.90 (m, 1H), 3.76 (s, 5H), -16.86 (d, 1H, J=29.6), -18.60 (d, 1H,J=13.8). Mass spectrum (FAB): m/e 1332 (P+), 1276 (base peak), 1248,1220, 1192, 1164, 1135, 1106, 1078, 1045.(254), reddish orange solid. 31 P NMR (121.4 MHz): 6 -33.3. 1 H NMR(400 MHz): 8 7.89 (m, 2H), 7.52 (m, 3H), 5.31 (m, 1H), 4.87 (m, 2H), 4.63(m, 1H), 4.55 (m, 1H), 4.42 (m, 1H), 4.34 (m, 1H), 4.24 (m, 1H), 4.21 (m,1H), 4.10 (s, 5H), 3.96 (m, 1H), 3.84 (m, 1H), -17.25 (d, 1H, J=30.5), -18.76(d, 11-1, J=14.6).(255), reddish orange solid. 31 P NMR (121.4 MHz): 6 43.5. 1 H NMR(300 MHz): 6 5.12 (m, 1H), 4.48 (m, 2H), 4.31 (s, 5H), 4.24 (m, 2H), 4.10 (s,5H), 3.96 (m, 1H), 3.72 (m, 1H). Mass spectrum (FAB): m/e 1252 (P+, basepeak), 1224, 1196, 1168, 1139, 1110, 1082, 1054, 1026, 988, 960.(256), orange solid. 31 P NMR (121.4 MHz): 8 -26.7. 1 H NMR (300MHz): 8 7.81 (m, 1H), 7.54 (m, 1H), 7.32 (m, 1H), 7.06 (m, 1H), 5.04 (m, 2H),4.62 (m, 2H), 4.53 (m, 21-1), 4.30 (s, 1011), 4.18 (m, 2H), -18.53 (d, 11-1,J=13.0). Mass spectrum (FAB): m/e 1300 (P+), 1272 (base peak), 1244,1216, 1187, 1159, 1130, 1102, 1074, 1046.(257), reddish orange solid. 31p NMR (121.4 MHz): 8 146.9. 1 H NMR(300 MHz): 8 8.15 (m, 2H), 7.55 (m, 2H), 7.46 (m, 1H), 5.88 (m, 1H), 5.60(m, 1H), 4.74 (s, 511), 4.47 (m, 1H), 4.40 (m, 1H), 4.29 (s, 5H), 4.12 (m, 1H),3.90 (m, 1H), 3.78 (m, 1H), -18.71 (bs, 1H). Mass spectrum (FAB): m/e1274 (P+), 1244 (base peak), 1216, 1188, 1160, 1132, 1104, 1076, 1048.Anal. calcd. for C34H23Fe2080s3P: C, 32.08; H, 1.82. Found: C, 31.72; H, 1.59.(258), reddish orange solid. 31 P NMR (121.4 MHz): 8 150.2. 1 H NMR151(300 MHz): 8 8.07 (m, 2H), 7.60-7.45 (m, 3H), 5.61 (m, 1H), 5.37 (m, 1H),4.68 (m, 1H), 4.47 (s, 5H), 4.33 (m, 1H), 4.18 (s, 5H), 4.11 (m, 1H), 3.98 (m,1H), 3.67 (m, 1H), -18.79 (bs, 1H). Mass spectrum (FAB): m/e 1274 (P+,base peak), 1244, 1216, 1188, 1160, 1132, 1104, 1076, 1048.(259), brownish orange solid. 31P NMR (121.4 MHz): 8 -13.9. 1 H NMR(300 MHz): 8 8.12 (m, 1H), 7.62 (m, 1H), 7.48 (m, 1H), 7.15 (m, 1H), 4.89(m, 2H), 4.67 (m, 2H), 4.48 (m, 2H), 4.21 (s, 10H), 3.97 (m, 2H), -12.01 (d,1H, J=6.8). Mass spectrum (FAB): m/e 1330 (P+), 1302 (base peak), 1274,1246, 1218, 1190, 1161, 1133, 1104, 1076, 1048, 970.(260),pink solid. 31 P NMR (121.4 MHz): 8 -15.8. 1 H NMR (300 MHz): 87.83 (m, 2H), 7.45-7.38 (m, 3H), 5.23 (m, 2H), 4.86 (m, 2H), 4.57 (m, 2H),4.25 (m, 2H), 4.18 (s, 5H), 4.01 (m, 2H), 3.74 (m, 2H), -12.51 (d, 1H, J=19.3).Mass spectrum (FAB): m/e 1300 (P+, base peak), 1272, 1244, 1216, 1188,1160, 1132, 1104, 1076, 1048, 970.(261), orange solid. 31 13 NMR (121.4 MHz): 8 -20.4. 1 H NMR (500MHz): 8 7.76-7.60 (bm, 2H), 7.50-7.34 (bm, 3H), 5.10-5.00 (m, 2H), 4.64 (m,1H), 4.55 (m, 1H), 4.45-4.30 (m, 3H), 4.08 (m, 1H), 4.02 (s, 5H), 3.42 (m,1H), 3.36 (m, 1H), 3.08 (m, 1H), -12.13 (d, 1H, J=4.5), -16.91 (d, 1H, J=12.5).Mass spectrum (FAB): m/e 1274 (P+, base peak), 1246, 1218, 1190, 1162,1134, 1106, 1078, 1050. Anal. calcd. for C34.5H24C1Fe2080s3P ,(261)•0.5CH2C12: C, 31.50; H, 1.84. Found: C, 32.60; H, 1.85.(262), orange solid. 31p NMR (121.4 MHz): 8 -22.0. 1 H NMR (500MHz): 8 7.85-7.70 (m, 2H), 7.45-7.25 (bm, 3H), 5.13 (m, 1H), 5.04 (m, 1H),4.72 (m, 1H), 4.59 (m, 1H), 4.52 (m, 2H), 4.33 (m, 1H), 4.13 (s, 5H), 3.99 (m,1H), 3.43 (m, 1H), 3.28 (m, 1H), 3.04 (m, 1H), -12.16 (d, 1H, J=3.87), -17.05(d, 1H, J=12.97). Mass spectrum (FAB): m/e 1274 (P+, base peak), 1246,1218, 1190, 1162, 1134, 1106, 1078, 1050.152(263), reddish brown solid. 31 P NMR (121.4 MHz): 6 39.3. 1 H NMR(400 MHz): 6 4.91 (t, 2H), 4.79 (t, 2H), 4.67 (t, 2H), 4.22 (m, 2H), 4.07 (s,5/1), 3.78 (q, 21-1), 3.12 (q, 214). Mass spectrum (FAB): m/e 1222 (P+, basepeak), 1194, 1166, 1138, 1110, 1082, 1054, 1026, 998, 970. Anal. calcd.for C29H17Fe2O9Os3P: C, 28.49; H, 1.40. Found: C, 28.66; H, 1.53.3.5.5 Pyrolysis of 0s3(C0)10(PFc2Ph)2(a) in octane for 18 hA solution of 0s3(C0)10(PFc2Ph)2  (50 mg, 0.028 mmol) in octane (20mL) was refluxed for 18 h after which the solvent was removed in vacuo.TLC revealed the presence of six major products and many minor ones aswas also shown by 31 P NMR spectroscopy. Hydride resonances in the 1 HNMR spectrum showed mainly those associated with 0s3(C0)8(}1)2[(C5H3PFcPh)Fe(C5H4)] (261).(b) in octane for 19.5 hA solution of 0s3(C0)10(PFc2Ph)2 (200 mg, 0.11 mmol) in octane (50mL) was refluxed for 19.5 h. The solvent was removed in vacuo and theresidue was chromatographed on silica with 3/1 petroleum ether/CH2C12 aseluent. The first band contained (252) (8%) by TLC, 1 H, and 31 P NMRspectroscopy. The second band (5%) contained complexes (253) and tracesof (254) identified by 31 P and 1 H NMR spectroscopy. The third band (3%)contained a mixture of three complexes. The fourth band (6%) containednew complexes (264) and (265). The fifth band contained complex (261)(20%). The sixth, seventh, and eighth bands (2%, 4%, and 6%) contained153mixtures. The ninth band contained complex (266) (5%). The tenth yellowband (4%) contained a complex unidentified mixture.The third band, yellow oily solid. 31 P NMR (121.4 MHz): 8 43.5, (255);41.1. 1 H NMR (400 MHz): 8 7.81, 7.53, 7.26, 5.12, 4.96, 4.54, 4.49, 4.38 (s),4.30 (s), 4.27, 4.24, 4.10 (s), 4.03, 3.95, 3.88^(s), 3.82, 3.72, 3.54. TLC: 3spots.(264) and (265), yellow solid. 31 P NMR (121.4 MHz): 8^14.3;^12.8(very small). 1 H NMR (400 MHz): 8 7.88, 7.71, 7.56, 7.50, 7.13, 7.00, 6.90,6.75, 5.00,^4.72,^4.64, 4.53,^4.41, 4.38,^4.35^(s),^4.28,^4.23,^4.15 (s), 4.09,4.02, 3.76, 3.68, -5.54 (d, J=25.9) (very small), -5.57 (d, J=23.4).(261), orange solid. 31 P NMR (121.4 MHz): 8 -20.2. 1 H NMR (300MHz): 8 7.74-7.62 (bm, 2H), 7.48-7.38 (bm, 3H), 5.09 (m, 1H), 5.06 (m, 1H),4.67 (m, 111), 4.57 (m, 111), 4.44 (m, 1H), 4.39 (m, 2H), 4.07 (m, 1H), 4.03 (s,5H), 3.43 (m, 114), 3.38 (m, 111), 3.10 (m, 111), -12.12 (d, 111, J=4.5), -16.91(d, 1H, J=12.6). Anal. calcd. for C34H23Fe2O8Os3P: C, 32.08; H, 1.82. Found: C,32.60; H, 1.85.The sixth band, orange solid. 31 P NMR (121.4 MHz): 6 22.7, 21.5, -25.7. TLC: 2 spots.The seventh band, pink solid. 31 P NMR (121.4 MHz): 8 145.0-134.0(broad), 22.8, 21.6. The 1 H NMR spectrum is very complex (hydrides): 8 -15.84 (dd, J1=14.2, J2=12.5).The eighth band, orange solid. 31 P NMR (121.4 MHz): 8 145.0-134.0(broad) (small), 43.6, 22.8, 21.6, -3.8, -22.6, -25.2, -28.3, -29.6, -30.5. TLC:5 spots including one the same as (262).(266), yellow solid. 31 P NMR (121.4 MHz): 8 -22.6, -30.0. Massspectrum (FAB): m/e 1785 (P+, base peak), 1757, 1729, 1712, 1695, 1668,1600, 1572, 1544, 1275, 1193, 1130, 1075, 1030.1543.5.6 Pyrolysis of 0s3(C0)11(PEt2Fc)A solution of 0s3(C0)11(PEt2Fc) (100 mg, 0.087 mmol) in octane (30mL) was refluxed for 8 h. The colour of the solution changed from brightreddish orange to dark orange. The solvent was removed in vacuo and thegreenish yellow residue was chromatographed on a silica column by using3/1 petroleum ether/CH2C12 as eluent. The first greenish yellow bandcontained 0s3(C0)12 (1%) identified by TLC and mass spectrometry(unusually, as its CH2C12 solvate shown by the mass specrtrum (FAB): m/e990 (P+, base peak), 962, 934, 906, 878, 865, 850). The second bandcontained complex (267) (15%). The third orange band contained unreactedstarting material (10%) identified by 31 P and 1 H NMR spectroscopy. Thefourth, fifth, and sixth bands contained complexes (268) (2%), (269) (65%),and (270) (2%), respectively.(267), yellow solid. 31 P NMR (81.0 MHz): 3 -50.8. 1 H NMR (200 MHz):3 4.50 (m, 1H), 4.38 (m, 21-1), 4.20 (m, 1H), 4.16 (s, 51-1), 2.88 (m, 111), 2.52(m, 1H), 2.24 (d, 3H, Jp_H=24.2), 1.50 (td, 3H, Jp_H=24.0), -15.13 (d, 1H,J=9.6), -19.62 (d, 1H, J=10.0). Mass spectrum (FAB): m/e 1096 (P+, basepeak), 1068, 1040, 1012, 984, 956, 928, 913, 900, 883, 872, 854, 844, 827,816. Anal. calcd. for C23H19Fe090s3P: C, 25.19; H, 1.75. Found: C, 25.40; H,1.72.(268), orange solid. 3 1 P NMR (81.0 MHz): 8 22.3. 1 H NMR (200 MHz): 64.80 (m, 1H), 3.36 (m, 1H), 3.00 (m, 1H), 2.15-1.90 (m, 21-1), 1.3-0.9 (m, 31-1),-19.50 (d, 1H, J=12.5).(269), orange solid. 31 P NMR (81.0 MHz): 8 -22.7. 1 H NMR (200 MHz):8 5.16 (m, 1H), 5.02 (m, 1H), 4.71 (m, 1H), 4.18 (m, 2H), 4.06 (m, 1H), 3.08(m, 1H), 2.18 (m, 1H), 1.86 (m, 2H), 1.28 (m, 1H), 1.04-0.90 (bm, 6H), -12.22 (d, 1H, Jp_H=4.5, satellite, Jo s -H=36.0), -17.39 (d, 1H, Jp_H=11.4,155satellite, Jos-H=45.6). Mass spectrum (FAB): m/e 1068 (Pt), 1040, 1012(base peak), 984, 956, 928, 900, 872, 844, 827, 816, 788. Anal. calcd. forC22H19FeO8 Os3P: C, 24.72; H, 1.79. Found: C, 24.99; H, 1.92.(270), greenish orange solid. 3 1 P NMR (81.0 MHz): 5 -20.7. 1 H NMR(200 MHz): 8 4.85 (m, 1H), 4.62 (m, 1H), 4.21 (s, 5H), 4.07 (m, 1H), 2.07 (m,2H), 1.87 (m, 2H), 1.03 (m, 6H), -14.39 (d, 1H, J=4.3).3.5.7 Pyrolysis of 0s3(C0)8(11)2[(C5H3PEt2)Fe(C5114)] (269)A solution of (269) (50 mg, 0.047 mmol) in decalin (15 mL) wasrefluxed for 30 min after which the solvent was removed in vacuo. 31 PNMR spectroscopy revealed the presence of mainly complex (269) and aresonance at 164.0 ppm (10%) and some small signals at 250.8, 145.9, 52.0,-25.9, -65.5 ppm including those of (267) and (270) which were alsoconfirmed by their respective hydride resonances in the 1 H NMR spectrum.3.5.8 Pyrolysis of 0s3(C0)12 with PEt2Fc in 1:2 molar ratioA solution of 0s3(C0)12 (272 mg, 0.30 mmol) and PEt2Fc (160 mg,0.60 mmol) in p-xylene (40 mL) was refluxed for 10 h. 3 1 P NMRspectroscopy revealed the following resonances in significant intensities:4.6, 0.9, -8.7, -9.6, -17.0, -17.7, -18.6, -19.4, -19.6, -20.0, -22.3, -24.6, -25.8, -30.6, -62.1, -62.7. Interesting hydride resonances in the 1 H NMRspectrum include those at -12.56 (d),^-13.13 (d),^-13.33 (dd),^-14.68 (d),^-14.86^(t),^-15.11^(d),^-15.39^(d),^-16.26^(d), -17.32^(d), -19.30 (dd), -19.45(d), -20.48 (m), -21.05 (d). The solvent was removed in vacuo and theresidue was applied to a silica chromatographic column by using 3/1petroleum ether/CH2C12 as eluent. The first greenish yellow band contained156unreacted 0s3(C0)12 (5%). The second band contained mainly complex(271) and some of its isomer (272) ((271)/(272)>20/1), and the third bandcontained almost equal amounts of (271) and (272). These were separatedby careful repeated chromatography: (271) (20%); (272) (14%). The fourthorange band contained (269) (10%) identified by TLC, 1 H, and 31 P NMRspectroscopy. The fifth band contained complex (273) (8%). The sixthbrown band (2%) contained a mixture of three complexes by TLC. Anumber of bands after the sixth band were not eluted.(271), reddish orange solid. 31 P NMR (121.4 MHz): 8 -24.6, -62.7. 1 HNMR (300 MHz): 6 4.49 (m, 3H), 4.34 (m, 1H), 4.28 (m, 4H), 4.23 (s, 5H),4.17 (s, 5H), 2.97 (m, 111), 2.72 (m, 1H), 2.42 (dd, 3H, J1=18, J2=5), 2.20 (bm,4H), 1.57 (m, 3H), 1.25 (bm, 6H), -14.82 (pt, 1H, J1=J2=9.9), -20.42 (pt, 1H,J1=J2=11.0). Mass spectrum (FAB): m/e 1342 (P+), 1314, 1286 (base peak),1258, 1230, 1200, 1172, 1142. Anal. calcd. for C36H38Fe2080s3P2: C, 32.20;H, 2.85. Found: C, 31.85; H, 2.70.(272), reddish orange solid. 31p NMR (121.4 MHz): 8 -25.8, -62.1. 1 HNMR (300 MHz): 8 4.5-4.3 (m, 8H), 4.28 (s, 5H), 4.22 (s, 5H), 2.83 (m, 1H),2.72 (m, 1H), 2.55 (dd, 3H, Ji=18, J2=5), 2.20 (bm, 4H), 1.57 (m, 3H), 1.25(bm, 6H), -15.13 (pt, 1H, J1=J2=10.0), -20.60 (dd, 1H, J1=11.0, J2=8.8). Anal.calcd. for C36H38Fe2O8Os3P2: C, 32.20; H, 2.85. Found: C, 32.02; H, 2.74.(273), orange solid. 31 P NMR (121.4 MHz): 8 48.3, -8.0, J=20.2. 1 HNMR (300 MHz): 8 4.59 (m, 1H), 4.47 (m, 1H), 4.41 (m, 2H), 4.32 (m, 1H),4.28 (s, 5H), 4.21 (m, 1H), 4.13 (m, 3H), 3.98 (m, 1H), 3.77 (m, 1H), 2.72 (m,2H), 2.58-2.40 (m, 4H), 2.20-2.05 (m, 2H), 1.53 (m, 311), 1.38 (m, 311), 1.35-1.15 (m, 6H), -16.09 (dd, 11-1, J1=14.5, J2=5.8), -16.66 (dd,1H, J1=22.0,J2=8.5).1573.5.9 Pyrolysis of 0s3(C0)11(PFc iPr2)A solution of 0s3(C0)11(PFciPr2) (120 mg, 0.10 mmol) in octane (30mL) was refluxed for 5 h. The colour of the solution changed from goldenyellow to brownish red in 1 h. 31 13 NMR spectroscopy revealed thepresence of four major products and a number of minor ones. The solventwas removed in vacuo and the dark residue was chromatographed on asilica column with 3/1 petroleum ether/CH2C12 as eluent. The first toseventh bands contained complexes (274) (6%), (275) (20%), (276) (22%),(277) (12%), (278) (20%), (279) (5%), and (280) (2%), respectively. The lastband (2%) contained a mixture of three complexes. Crystals of (278),obtained by slow evaporation of 3/1 petroleum ether/CH2C12 solution,were suitable for a successful X-ray diffraction study. Crystals of (274),(275), and (279), all obtained by slow evaporation of 1/1 hexanes/CH2C12solutions, await structure determinations.(274), yellow solid. 31 13 NMR (121.4 MHz): 8 203.9. 1 H NMR (300MHz): 6 5.77 (t, 1H), 5.08 (d, 1H), 4.68 (s, 5H), 3.74 (d, 1H), 3.03 (m, 1H,CHMe2), 2.44 (m, 1H), 1.78 (dd, 3H), 1.75-1.62 (overlapping dd, 9H), -18.78(bs, 1H). Mass spectrum (FAB): m/e 1096 (Pt), 1082, 1068 (base peak),1040, 1026, 1012, 998, 984, 956, 940, 928, 914, 900, 886, 872, 844, 828,788. Anal. calcd. for C24H23Fe080s3P: C, 26.28; H, 2.11. Found: 26.02; H,2.28.(275), brownish red solid. 31 P NMR (81.0 MHz): 6 0.0. 1 H NMR (300MHz): 6 5.28 (d, 1H, J=2.2), 5.26 (m, 1H), 5.00 (d, 1H, J=2.2), 4.65 (m, 1H),4.62 (m, 1H), 3.96 (t, 1H, J=2.2), 3.93 (m, 1H), 2.81 (m, 1H), 2.54 (m, 1H),1.71 (dd, 3H, J1=16.8, J2=7.4), 1.41 (dd, 3H, J1=13.6, J2=7.0), 1.37 (dd, 3H,J1=12=7.6), 1.32 (dd, 3H, J1=10.2, J2=7.4), -17.21 (dd, 1H, J1.28.0, J2=1.5), -18.99 (dd, 1H, J1=12.2, J2=1.5). Mass spectrum (FAB): m/e 1152 (P+, base158peak), 1124, 1096, 1078, 1068, 1048, 1034, 1020, 1006, 992, 978, 964,948, 934, 920, 906, 894, 878, 838. Anal. calcd. for C26H23 FeO10Os3P: C,27.09; H, 2.01. Found: C, 27.23; H, 2.11.(276), orange solid. 31 P NMR (121.4 MHz): 6 73.2 (broad). 1 H NMR(300 MHz): 8 4.33 (m, 1H), 4.26 (m, 2H), 4.04 (s, 5H), 2.12 (m, 1H), 1.63 (dd,3H, Ji=18.5, J2=7.3), 1.53 (dd, 3H, J1=17.7, J2=6.9), -17.35--17.65 (verybroad, 111), -17.85--18.40 (very broad, 1H). Mass spectrum (FAB): m/e1082 (P+, base peak), 1054, 1026, 998, 970, 942, 914, 870, 844, 788. Anal.calcd. for C22H17Fe090s3P: C, 24.40; H, 1.58. Found: C, 24.28; H, 1.62.(277), yellow solid. 31P NMR (81.0 MHz): 6 14.3. 1 H NMR (400 MHz): 84.52 (m, 1H), 4.35 (m, 2+1H), 4.25 (s, 5H), 2.42 (m, 1H), 1.33 (dd, 3H), 1.09(dd, 3H). Mass spectrum (FAB): m/e 1108 (Pt, base peak), 1080, 1052,1024, 996, 982, 968, 954, 940, 926, 912, 898, 884, 870, 856, 842, 828,814, 786. Anal. calcd. for C23H15Fe0100s3P: C, 24.91; H, 1.36. Found: C,25.30; H, 1.58.(278), reddish orange solid. 31 P NMR (121.4 MHz): 3 2.5. 1 H NMR (400MHz): 8 5.41 (m, 1H), 5.12 (m, 1H), 4.77 (m, 114), 4.31 (m, 1H), 4.24 (m, 1H),4.12 (m, 1H), 3.08 (m, 1H), 2.55 (m, 1H), 1.86 (m, 1H), 1.43 (dd, 3H), 1.36(dd, 6H), 1.25 (dd, 3H), -12.07 (d, 1H, J=4.1), -17.13 (d, 1H, J=12.0). Massspectrum (FAB): m/e 1096 (Pt), 1068, 1040 (base peak), 1012, 984, 956,942, 928, 914, 900, 886, 872, 858, 844, 826, 788. Anal. calcd. forC24H23Fe080s3P: C, 26.28; H, 2.11. Found: C, 26.40; H, 2.17.(279), greenish yellow solid. 31 P NMR (81.0 MHz): 3 11.2. 1 H NMR(400 MHz): 8 4.98 (m, 1H), 4.88 (m, 1H), 4.67 (m, 1H), 4.47 (s, 5H), 2.47 (m,1H), 2.29 (m, 1H), 1.67 (dd, 3H), 1.56 (dd, 3H), 1.22 (dd, 3H), 0.85 (dd, 3H),-15.23 (d, 1H, J=14.6). Mass spectrum (FAB): m/e 1124 (Pt), 1096, 1068,1040 (base peak), 1012, 988, 974, 960, 932, 918, 870, 856, 846, 826, 800,159788. Anal. calcd. for C25H23FeO9Os3P: C, 26.69; H, 2.06. Found: C, 26.53; H,1.98.(280), yellow solid. 1 H NMR (300 MHz): 6 5.11 (m, 1H), 5.03 (m, 1H),4.44 (m, 2H), 4.30 (m, 2H), 4.21 (m, 1H), 4.06 (m, 1H), 2.54 (m, 2H), 1.50(dd, 3H), 1.33 (dd, 3H), 1.06 (dd, 3H), 0.86 (m, 3H), -13.2 (d, 1H, J=8.4).Mass spectrum (FAB): m/e 1152 (P+, base peak), 1124, 1096, 1068, 1040,1012, 988, 974, 960, 946, 932, 918, 904, 890, 876, 862, 848, 834, 790.The last band, brownish orange solid. 31 P NMR (121.4 MHz): 6 287.0,5.2 (small). TLC: 3 spots.3.5.10 Pyrolysis of 0s3(C0)12 with PnBuFcPhA solution of 0s3(C0 )12 (272 mg, 0.30 mmol) and PnBuFcPh (100 mg,0.29 mmol) in octane (30 mL) was refluxed for 4 h. 31 13 NMR spectroscopy-95.7 ppm. Many other minor signals were also present. The solvent wasremoved in vacuo and the solid residue was subjected to chromatographicseparation on silica by using 4/1 petroleum ether/CH2C12 as eluent. Carefulanalyses of the collected bands gave the following compounds in the orderof elution (0s3(C0)12 (2%) eluted as the first band): (281) (3%), (282) (3%),(283) (4%), (284) (1%), (285) (11%), (286) (8%), (287) (6%), (288) (4%),(289) (2%), (290) (2%), (291) (6%), (292) (8%), (293) (6%), (294) (6%).Crystals of (281) and (282), obtained from 3/1 hexane/CH2C12 solutions,await analysis.(281), greenish orange solid. 31 P NMR (121.4 MHz): 6 209.8. 1 H NMR(300 MHz): 6 4.95 (d, 2H, J=2.7), 4.12 (s, 5H), 3.91 (t, 1H, J=2.7), 3.03 (m,2H), 1.92 (m, 2H), 1.62 (m, 2H), 1.04 (t, 3H). Mass spectrum (FAB): m/erevealed the following major resonances: 209.9, 164.6, 151.3, 133.5,^56.7,34.0,^-5.9,^-6.0,^-10.1,^-10.5,^-10.6,^-20.1, -58.4, -59.2, -59.3, -91.8,^and1601094- (Pt), 1066 (base peak), 1038, 1010, 982, 954, 926, 898, 870, 842,814, 786. Anal. calcd. for C23H17Fe090s3P: C, 25.23; H, 1.57. Found: C, 25.49;H, 1.70.(282), orange solid. 31P NMR (121.4 MHz): 3 -91.8. 1H NMR (300MHz): 8 8.90-8.50 (m, 2H), 7.10-6.70 (m, 3H), 4.42 (m, 2H), 4.23 (s, 5H),3.80 (m, 1H), 2.62 (m, 2H), 2.10 (m, 2H), 1.62 (m, 2H), 0.88 (m, 3H), -16.87(d, 1H, J=9.6). Mass spectrum (FAB): m/e 1172 (Pt, base peak), 1144, 1116,1088, 1060, 1032, 1010, 1004, 982, 976, 948, 926, 898, 870, 842, 814.Anal. calcd. for C19H23Fe090s3P: C, 29.70; H, 1.98. Found: C, 30.02; H, 2.07.(283), orange solid. 31p NMR (121.4 MHz): 6 -95.7. 1 11 NMR (300MHz): 8 8.90-8.50 (m, 2H), 7.10-6.70 (m, 3H), 4.25 (m, 1H), 4.17 (m, 1H),4.13 (s, 5H), 4.11 (m, 1H), 2.65 (m, 2H), 1.87 (m, 2H), 1.30 (m, 2H), 0.92 (m,3H), -16.66 (d, 1H, J=8.1). Mass spectrum (FAB): m/e 1172 (Pt base peak),1144, 1116, 1088, 1060, 1032, 1010, 1004, 982, 976, 948, 926, 898, 870,842, 814. Anal. calcd. for C19H23Fe090s3P: C, 29.70; H, 1.98. Found: C, 29.96;H, 2.14.(284), orange solid. 31p NMR (121.4 MHz): 8 59.4. 1 H NMR (300 MHz):8 4.81 (m, 21-1), 4.63 (m, 211), 4.14 (m, 2H), 3.76 (m, 2H), 2.88 (m, 2H), 1.94(m, 2H), 1.64 (m, 2H), 1.13 (t, 3H). Mass spectrum (FAB): m/e 1094 (P+),1066, 1038 (base peak), 1010, 982, 954, 926, 870, 842, 814, 786, 758.Anal. calcd. for C23H17Fe090s3P: C, 25.23; H, 1.57. Found: C, 25.51; H, 1.72.(285), orange solid. 31 P NMR (121.4 MHz): 8 56.7. 1 H NMR (300 MHz):3 4.23 (complex m, 3H), 4.11 (s, 5H), 2.60 (bm, 1H), 2.13 (bm, 1H), 1.95(bm, 111), 1.77 (bm, 1H), 1.58 (bm, 2H), 1.03 (bt, 3H). Mass spectrum (FAB):m/e 1122 (P+, base peak), 1094, 1066, 1038, 1010, 982, 954, 926, 898,870, 842, 814, 786. Anal. calcd. for C241117Fe0100s3P: C, 25.67; H, 1.53.Found: C, 25.84; H, 1.67.161(286), reddish orange solid. 31 P NMR (121.4 MHz): 6 -20.1. 1 H NMR(300 MHz): 8 7.60-7.40 (m, 2H), 7.30-7.15 (m, 3H), 4.54 (m, 1H), 4.42 (m,2H), 4.28 (m, 1H), 4.10 (s, 5H), 2.87 (bm, 2H), 2.04 (bm, 2H), 1.52 (m, 2H),1.12 (t, 3H). Mass spectrum (FAB): m/e 1228 (P+), 1200, 1172 (base peak),1144, 1116, 1094, 1088, 1060, 1032, 1010, 1004, 976, 948, 920, 892, 864,842. Anal. calcd. for C311123Fe0110s3P: C, 30.30; H, 1.89. Found: C, 30.58; H,1.97.(287), orange solid. 31 P NMR (121.4 MHz): 8 -10.1. 1 H NMR (300MHz): 8 7.50-7.30 (m, 2H), 6.79-6.64 (m, 2H), 4.23 (m, 1H), 4.16 (m, 1H),4.11(m, 1H), 4.06 (s, 5H), 3.97 (m, 1H), 2.53 (bm, 2H), 1.96 (m, 2H), 1.64(m, 2H), 1.18 (t, 3H), -17.89 (d, 1H, J=15.6). Mass spectrum (FAB): m/e1172 (P+), 1144, 1116, 1088 (base peak), 1060, 1032, 1010, 1004, 982,976, 948, 926, 898, 870, 842, 814. Anal. calcd. for C29H23Fe090s3P: C, 29.70;H, 1.98. Found: C, 29.91; H, 2.12.(288), orange solid. 31 P NMR (121.4 MHz): 6 -10.6. 1 H NMR (300MHz): 8 7.03 (m, 2H), 6.75 (m, 1H), 6.58 (m, 1H), 4.32 (m, 1H), 4.27 (m, 1H),4.14 (s, 5H), 4.09 (m, 1H), 3.02 (m, 1H), 2.60 (m, 2H), 2.08 (m, 2H), 1.62 (m,2H), 1.06 (t, 3H), -17.80 (d, 1H, J=15.9). Mass spectrum (FAB): m/e 1172(P+), 1144, 1116, 1088 (base peak), 1060, 1032, 1010, 1004, 982, 976,948, 926, 898, 870, 842, 814. Anal. calcd. for C29H23Fe090s3P: C, 29.70; H,1.98. Found: C, 29.81; H, 2.05.(289), orange solid. 31 P NMR (121.4 MHz): 8 -16.1. 1 H NMR (300MHz): 8 7.7-7.3 (bm, 5H), 5.31 (m, 1H), 5.15 (m, 1H), 4.82 (m, 1H), 4.63 (m,1H), 4.42 (m, 1H), 3.98 (m, 1H), 3.51 (m, 1H), 2.55(m, 2H), 2.20 (m, 2H),1.62 (m, 2H), 0.93 (m, 3H), -12.14 (d, 1H, J=4.8), -16.99 (d, 1H, J=12.9).Mass spectrum (FAB): m/e 1144 (P+, base peak), 1116, 1088, 1060, 1032,1010, 1004, 982, 976, 948, 926, 898, 870, 842, 814.162(290), orange solid. 31 P NMR (121.4 MHz): 6 -17.7. 1 H NMR (300MHz): 5 7.7-7.3 (bm, 5H), 5.45 (m, 1H), 5.21 (m, 1H), 4.77 (m, 1H), 4.72 (m,111), 4.26 (m, 11-1), 4.18 (m, 1H), 3.90 (m, 1H), 2.64 (m, 211), 2.23 (m, 2H),1.58 (m, 211), 0.76 (m, 3H), -12.30 (d, 1H, J=4.5), -17.06 (d, 111, J=12.0).Mass spectrum (FAB): m/e 1144 (P+, base peak), 1116, 1088, 1060, 1032,1010, 1004, 982, 976, 942, 926, 898, 870, 842, 814. Anal. calcd. forC28H23FeO8Os3P: C, 29.37; H, 2.02. Found: C, 29.80; H, 2.21.(291), reddish orange solid. 31P NMR (121.4 MHz): 8 151.3. 1 H NMR(300 MHz): 6 7.89 (m, 2H), 7.35 (m, 2H), 4.46 (m, 2H), 4.41 (m, 2H), 4.33(m, 2H), 4.29 (s, 10H), 3.96 (m, 2H), 2.92 (m, 2H), 2.63 (m, 211), 2.42 (m,2H), 1.95 (m, 2H), 1.43 (bm, 411), 0.95 (t, 6H). Mass spectrum (FAB): m/e1388 (P+), 1360, 1332 (base peak), 1304, 1276, 1248, 1220, 1192, 1136,1080. Anal. calcd. for C41H40Fe2O7Os3P2: C, 35.45; H, 2.90. Found: C, 35.80;H, 3.12.(292), orange solid. 31 P NMR (121.4 MHz): 8 164.6, 133.5, J=148.8. 1 HNMR (300 MHz): 8 7.6-7.4 (m, 2H), 6.7-6.6 (m, 2H), 4.50 (m, 111), 4.42 (m,211), 4.31 (s, 511), 4.27 (m, 211), 4.08 (s, 5H), 3.96 (m, 111), 3.88 (m, 2H), 2.92(m, 211), 2.68 (m, 211), 2.43 (m, 2H), 2.38 (m, 211), 1.35 (m, 411), 1.0-0.8 (m,611). Mass spectrum (FAB): m/e 1388 (P+), 1360, 1332 (base peak), 1304,1276, 1248, 1220, 1192, 1136, 1080.(293), orange solid. 31 P NMR (121.4 MHz): 6 -25.8, -58.2. 1 H NMR(300 MHz): 6 7.7-7.3 (bm, 10H), 4.50 (m, 211), 4.42 (m, 3H), 4.36 (s, 5H),4.30 (m, 1H), 4.21 (s, 5H), 4.04 (m, 2H), 2.43 (m, 2H), 2.00 (m, 2H), 1.92 (m,211), 1.50 (m, 411), 1.02 (m, 3H), 0.90 (m, 3H), -14.72 (dd, 1H, J1=1 0.6,J2=8.0), -19.62 (t, 1H, J1=J2=10.7). Anal. calcd. for C48H46Fe2O8Os3P2: C,38.56; H, 3.10. Found: C, 38.98; H, 3.36.163(294), orange solid. 31 P NMR (121.4 MHz): 8 -26.5, -59.0. 1 H NMR(300 MHz): 8 7.8-7.6 (m, 4H), 7.5-7.2 (m, 6H), 4.62 (m, 2H), 4.48 (m, 2H),4.40 (s, 511), 4.31 (s, 5H), 4.20 (m, 2H), 3.96 (m, 2H), 2.68 (m, 211), 2.13 (m,2H), 1.90 (m, 2H), 1.61 (m, 2H), 1.47 (m, 2H), 1.10 (m, 311), 0.88 (m, 3H), -15.03 (t, 1H, Ji=J2=10.3), -19.81 (t, 1H, Ji=J2=11.3).The last band, orange solid. 3 1 P NMR (121.4 MHz): 8 115.1, 112.7,111.5. TLC: 3 spots.A major component (-15%) of the initial reaction mixture had a 31 PNMR resonance at 34.0 ppm, but it was not found in any band. Likewise, afew minor complexes initially showing 31 P NMR resonances at 211.2, 147.8,122.7, 121.6, 24.8, -5.6, and -55.0 ppm were not found.3.5.11 Pyrolysis of 0s3(C0)12 with PtBu2FcA solution of 0s3(C0)12 (200 mg, 0.22 mmol) and PtBu2Fc (80 mg,0.24 mmol) in toluene (50 mL) was refluxed for 6 h. The initial brightorange colour turned to dark red. TLC showed the formation of three majorproducts. 31 P NMR spectroscopy revealed major resonances at 58.6, 52.5,and 37.1 ppm. Two major hydride resonances at -17.53 (d, J=30.3) and -18.49 ppm (d, J=9.0), and two minor ones at -12.87 (d, J=7.2) and -14.54ppm (d, J=4.8) were observed. The solvent was removed in vacuo and theresidue was chromatographed on silica by using 4/1 petroleum ether/CH2C12 as eluent. The first greenish yellow band contained unreacted0s3(C0)12 (3%). The second band contained complex (295) (20%). The thirdband (3%) contained a mixture. The fourth band contained complex (296)(4%). The fifth band contained complex (297) (3%). The sixth bandcontained complex (298) (3%). The seventh band (1%) contained a mixture.The eighth band contained complex (299) (8%). A major product (-35%)164with 31 P NMR resonance at 58.6 ppm was not found and presumablyadsorbed on column. Crystals of (295), (298), and (299), obtained from 2/1hexane/CH2C12 solutions, await structure determinations.(295), purple solid. 31 P NMR (121.4 MHz): 8 37.1. 1 H NMR (300 MHz):8 5.25 (m, 1H), 5.18 (m, 1H), 4.92 (m, 2H), 4.53 (m, 2H), 3.95 (m, 1H), 3.78(m, 1H), 2.30 (d, 2H, J=14.3), 1.74 (d, 3H, J=13.3), 1.69 (d, 3H, J=9.1), 1.40(d, 9H, J=13.2), -17.53 (d, 111, J=30.3), -18.48 (d, 111, J=9.3). Anal. calcd. forC27H27FeO9Os3P: C, 28.13; H, 2.36. Found: C, 28.42; H, 2.56. Mass spectrum(FAB): m/e 1154 (P+), 1098 (base peak), 1070, 1042, 1014, 985, 957, 929,901, 873, 844, 816, 788.The third band, yellow solid. 31 P NMR (121.4 MHz): 5 50.2, 47.2, 40.3(very small). 1 H NMR (300 MHz): 8 4.70 (m), 4.65-4.50 (m), 4.31 (s), 4.26(s), 1.93 (d, J=19.6), 1.43 (d, J=14.2), 1.40 (d, J=14.7), 1.35 (d, J=14.4), -12.83 (d, J=5.1). TLC: 3 spots.(296), orange solid. 31 P NMR (121.4 MHz): 5 310.5. 1 H NMR (300MHz): 8 5.40 (m, 1H), 5.22 (m, 1H), 4.94 (s, 5H), 3.41 (m, 1H), 1.45 (d, 9H,J=14.1), -12.82 (d, 1H, J=6.8), -19.10 (d, 1H, J=9.0). Mass spectrum (FAB):m/e 1068 (P+, base peak), 1040, 1012, 984, 956, 927, 900, 871, 843, 815,787, 758.. (297), reddish orange solid. 31 P NMR (121.4 MHz): 8 62.8. 1 H NMR(300 MHz): 8 5.32 (m, 1H), 4.95 (m, 1H), 4.66 (m, 1H), 4.51 (m, 1H), 4.48(m, 111), 4.18 (m, 2H), 3.93 (m, 111), 1.58 (d, 18H, J=12.9), -12.87 (d, 1H,J=7.2). Anal. calcd. for C27H27Fe090s3P: C, 28.13; H, 2.36. Found: C, 28.37; H,2.49.(298), reddish orange solid. 31 P NMR (121.4 MHz): 8 67.6. 1 H NMR(300 MHz): 8 5.03 (m, 1H), 4.43 (s, 5H), 4.40 (m, 1H), 4.29 (m, 1H), 1.78 (d,18H, J=13.6), -14.53 (d, 1H, J=4.8).165The seventh band, orange solid. 31 13 NMR (121.4 MHz): 8 66.8, 54.5(medium), 52.6, 16.0 (major). TLC: 3 spots.(299), green solid. 31P NMR (121.4 MHz): 8 52.3. 1 H NMR (300 MHz): 84.43 (m, 1H), 4.37 (m, 1H), 4.31 (s, 5H), 4.27 (m, 1H), 0.98 (d, 9H, J=14.9).Anal. calcd. for C241-117Fe0100s3P: C, 25.67; H, 1.53. Found: C, 26.12; H, 1.62.3.5.12 Pyrolysis of 0s3(CO)12 with Fe(C5H4)2PPhA solution of 0s3(CO)12 (190 mg, 0.21 mmol) and Fe(C5H4)2PPh (65mg, 0.22 mmol) in octane (100 mL) was refluxed for 7 h. The solvent wasremoved in vacuo and the residue was chromatographed on a silica columnby using 3/1 petroleum ether/CH2C12 as eluent. The first greenish yellowband contained unreacted 0s3(CO)12 (10%). The small second (2%) andfourth (3%) orange bands were not characterized. The third band proved tobe complex (300) (70%). Crystals of (300) suitable for X-ray structuredetermination were obtained from a 2/1 pentane/CH2C12 solution.(300), red orange solid. 31 P NMR (121.4 MHz): 8 59.9. 1 H NMR (300MHz): 6 7.55-7.15 (bm, 5H), 4.77 (m, 2H), 4.70 (m, 2H), 4.62 (m, 2H), 3.00(m, 2H). Mass spectrum (FAB): m/e 1114 (P+, base peak), 1086, 1058,1030, 1002, 974, 946, 918, 890, 862. Anal. calcd. for C25.5H14C1Fe090s3P,(300)•0.5CH2C12: C, 26.47; H, 1.22. Found: C, 26.53; H, 1.30.3.5.13 Pyrolysis of 0s3(CO)12 with PEtFc2A solution of 0s3(CO)12 (110 mg, 0.12 mmol) and PEtFc2 (52 mg, 0.12mmol) in octane (70 mL) was refluxed for 19 h. The colour of the solutionchanged from bright orange to dark brown and TLC revealed the formationof more than fifteen products. 3 1 P NMR spectroscopy revealed majorresonances at 335.8, 213.5, 151.0, 148.4, 56.4, 31.0, -21.8, -23.2, -24.8, -16626.5, -27.4, -32.9, -34.5, and -80.5 ppm. The solvent was removed in vacuoand the residue was chromatographed on silica with 3/1 petroleumether/CH2C12 as eluent. The first greenish yellow band contained unreacted0s3(CO)12 (2%). The second band (2%) contained an unidentified mixture ofa yellow and a green complex by TLC. The third band (2%) contained anunidentified yellow complex. The fourth band (6%) contained complexes(301) and (302). The fifth band (2%) contained a mixture. The sixth,seventh, and eighth bands contained complexes (303) (12%), (304) (4%),and (305) (3%), respectively. The ninth band (7%) contained complexes(306) and (307). The tenth band (3%) contained a mixture. The eleventh,thirteenth, and fourteenth bands contained complexes (308) (20%), (309)(4%), and (310) (1%), respectively. The twelveth green band (1%) containedan unidentified compound. The fifteenth, sixteenth, and eighteenth bandsall contained mixtures. The seventeenth band contained complex (311)(1%), the diastereoisomer of (308). Crystals of (308) were obtained by slowevaporation of the eluted band. Crystals of (301), (303), and (305),obtained from 2/1 hexane/CH2C12 solutions, await analysis.(301), greenish orange solid. 31 P NMR (121.4 MHz): 8 -78.9. 1 H NMR(300 MHz): 8 5.14 (m, 1H), 4.88 (m, 2H), 4.69 (m, 1H), 4.41 (s, 5H), 4.27 (m,1H), 4.15 (s, 5H), 3.84 (m, 1H), 3.65 (m, 1H), 3.03 (m, 1H, Et), 2.82 (m, 1H,Et), 1.81 (m, 311), -17.80 (d, 1H, J=12.3). Mass spectrum (FAB): m/e 1252(P+, base peak), 1224, 1195, 1167, 1140, 1113, 1084, 1056, 1027, 1000,983. Anal. calcd. for C31H23Fe2090s3P: C, 29.72; H, 1.85. Found: C, 29.33; H,1.67.(302), greenish orange solid. 31 P NMR (121.4 MHz): 8 -85.7. 1 H NMR(300 MHz): 8 5.17 (m, 1H), 4.92 (m, 1H), 4.78 (m, 1H), 4.72 (m, 1H), 4.46 (s,5H), 4.22 (m, 1H), 4.10 (s, 5H), 3.98 (m, 1H), 3.74 (m, 1H), 2.96 (m, 111, Et),1672.77 (m, 1H, Et), 1.74 (m, 3H), -18.20 (d, 1H, J=11.4). Anal. calcd. forC31H23Fe2090s3P: C, 29.72; H, 1.85. Found: C, 29.49; H, 1.70.The fifth band, yellow solid. 31 P NMR (121.4 MHz): 8 52.2, 1.6. TLC: 3spots.(303), orange solid. 3 1 13 NMR (121.4 MHz): 6 148.5. 1H NMR (300MHz): 6 5.79 (m, 1H), 5.08 (m, 111), 4.68 (s, 5H), 4.55 (m, 2H), 4.46 (m, 1H),4.37 (m, 1H), 4.35 (s, 5H), 3.82 (m, 1H), 3.29 (m, 1H, Et), 3.11 (m, 1H, Et),1.73 (m, 3H), -18.65 (bs, 1H). Mass spectrum (FAB): m/e 1226 (P+, basepeak), 1198, 1170, 1141, 1113, 1085, 1057, 1029, 999. Anal. calcd. forC301-123Fe2080s3P: C, 29.42; H, 1.89. Found: C, 29.56; H, 2.03.(304), orange solid. 31 P NMR (121.4 MHz): 6 151.0. 1 H NMR (300MHz): 8 5.65 (m, 111), 5.27 (m, 1H), 4.77 (m, 214), 4.64 (m, 1H), 4.32 (m, 1H),4.23 (s, 5H), 4.08 (s, 5H), 3.94 (m, 1H), 2.90 (m, 111, Et), 2.78 (m, 1H, Et),1.72 (m, 3H), -18.59 (bs, 1H). Mass spectrum (FAB): m/e 1226 (P+, basepeak), 1197, 1170, 1142, 1113, 1085, 1057, 1029, 1000.(305), orange solid. 31P NMR (121.4 MHz): 8 32.6. 1 H NMR (300 MHz):8 4.36 (m, 1H), 4.31 (m, 1H), 4.25 (m, 2H), 4.05 (s, 5H), 2.64 (m, 2H, Et),1.27 (m, 3H), -16.50 to -17.30 (very broad, 1H), -17.50 to -18.80 (verybroad, 1H). Mass spectrum (FAB): m/e 1068 (P+, base peak), 1040, 1013,985, 957, 928, 899, 871, 844, 814. Anal. calcd. for C211-113Fe090s3P: C, 23.64;H, 1.23. Found: C, 23.97; H, 1.31.(306), yellow solid. 31P NMR (121.4 MHz): 6 -31.3. 1 H NMR (300 MHz):8 5.17 (m, 1H), 4.69 (m, 1H), 4.52 (m, 1H), 4.41 (m, 1H), 4.25 (m, 1H), 4.11(m, 2H), 4.07 (m, 1H), 4.01 (m, 1H), 3.92 (m, 1H), 3.83 (s, 5H), 3.64 (m, 1H),1.72 (m, 1H), 1.65 (m, 1H), 1.28 (m, 3H), -17.15 (dd, 1H, J1=27.3, J2=2.1), -18.96 (dd, 1H, J1=13.1, J2=2.1). Mass spectrum (FAB): m/e 1282 (P+), 1254,1681225 (base peak), 1197, 1169, 1141, 1113, 1085, 1056, 1029, 1001. Anal.calcd. for C32H23Fe20100s3P: C, 30.01; H, 1.82. Found: C, 29.74; H, 1.83.(307), reddish orange solid. 31 P NMR (121.4 MHz): 6 -32.9. 1 H NMR(300 MHz): 6 5.20 (m, 1H), 4.84 (m, 1H), 4.80 (m, 1H), 4.58 (m, 2H), 4.43(m, 1H), 4.37 (m, 1H), 4.21 (s, 5H), 4.14 (m, 1H), 4.05 (m, 1H), 3.87 (m, 1H),3.66 (m, 1H), 1.73 (m, 1H), 1.68 (m, 1H), 1.25 (m, 3H), -17.10 (dd, 1H,J 1=27.6, J2=2.0), -18.39 (dd, 111, J1=11.2, J2=2.0). Anal. calcd. forC32H23Fe20100s3P: C, 30.01; H, 1.82. Found: C, 29.69; H, 1.74.The tenth band, dark orange solid. 31 P NMR (121.4 MHz): 8 274.9,163.4, -21.6. TLC: 4 spots with one being 0s3(C0)11(PEtFc2).(308), orange solid. 31 P NMR (121.4 MHz): 8 -27.4. 1 H NMR (300MHz): 6 4.99 (m, 2H), 4.62 (m, 1H), 4.54 (m, 1H), 4.41 (m, 2H), 4.32 (m, 1H),4.28 (m, 1H), 4.24 (s, 5H), 4.01 (m, 1H), 3.26 (m, 1H), 3.00 (m, 1H), 2.68 (m,2H, Et), 1.22 (td, 3H, Jp_H=15.2, JH_H=7.8), - 12.13 (d, 1H, J=4.3), - 17.04 (d,111, J=12.3). Mass spectrum (FAB): m/e 1224 (P+, base peak), 1196, 1168,1140, 1112, 1085, 1057, 1029, 1000. Anal. calcd. for C30H23Fe2O8Os3P: C,29.42; H, 1.89. Found: C, 29.48; H, 1.95.(309), red solid. 31p NMR (121.4 MHz): 5 58.0. 1 H NMR (300 MHz): 84.74 (m, 2H), 4.61 (m, 2H), 4.55 (m, 2H), 3.13 (m, 2H), 2.74 (m, 2H, Et), 1.30(m, 3H). Mass spectrum (FAB): m/e 1067 (P+, base peak), 1040, 1012, 983,955, 927, 899, 871, 843, 815.(310), orange solid. 31 P NMR (121.4 MHz): 6 116.6, -38.0, J=99.3. 1 HNMR (300 MHz): 8 5.22 (m, 1H), 5.03 (m, 1H), 4.64 (m, 2H), 4.57 (m, 2H),4.46 (m, 3H), 4.38 (s, 5H), 4.32 (m, 1H), 4.23 (m, 2H), 4.18 (s, 5H), 4.01 (m,1H), 3.87 (m, 1H), 3.42 (m, 1H), 2.85 (m, 1H, Et), 2.76 (m, 1H, Et), 2.72 -2.65(m, 2H, Et), 1.34 (m, 3H), 1.21 (m, 3H), -20.68 (dd, 1H, J1=11.4, J2=9.0).169The fifteenth band, greenish orange solid. 31 13 NMR (121.4 MHz): 6172.1, 61.4, 18.0, -19.4. TLC: 4 spots.The sixteenth band, red solid. 31 P NMR (121.4 MHz): 6 212.7, 211.8.TLC: 2 spots.(311), reddish orange solid. 31 P NMR (121.4 MHz): 6 -26.5. 1 H NMR(300 MHz): 8 4.92 (m, 1H), 4.85 (m, 1H), 4.54 (m, 1H), 4.42 (m, 2H), 4.36(m, 1H), 4.29 (s, 5H), 4.24 (m, 1H), 4.10 (m, 1H), 3.96 (m, 1H), 3.32 (m, 1H),3.14 (m, 1H), 2.51 (m, 2H, Et), 1.30 (td, 3H, Jp-H=14.7, JH-H=7.6), -12.17 (d,1H, J=3.9), -17.45 (d, 111, J=11.7).The eighteenth band, brownish orange solid. 31p NMR (121.4 MHz): 6226.6, 221.3, 216.2, 215.2. 1 11 NMR (hydrides only) (300 MHz): 6 -17.88 (d,J=19.2), -17.90 (d, J=19.2). TLC: 4 spots.Those complexes showing 31 P NMR resonances at 335.8 and -80.5ppm were not found.3.5.14 Pyrolysis of 0s3(C0)11(PEtFc2)A solution of 0s3(C0)11(PEtFc2) (100 mg, 0.076 mmol) in octane (50mL) was refluxed for 11 h. 31 P NMR spectroscopy revealed majorresonances at 150.8, 148.2, -21.8, -26.5, -27.4, -92.8, and -111.0 ppm. Thesolvent was removed in vacuo and the residue was chromatographed onsilica with 3/1 petroleum ether/CH2C12 as eluent. The first orange bandcontained (303) (20%). The second orange band contained (304) (6%). Thethird band proved to be the starting material (10%). The fourth orangeband contained (308) (30%). The fifth reddish orange band (5%) containedan unidentified mixture. The sixth orange band contained (311) (2%). Allthe previously characterized complexes were identified by TLC, 31 P, and 1 HNMR spectroscopy.1703.5.15 Pyrolysis of 0s3(C0)12 with AsFc2PhA solution of 0s3(C0)12 (272 mg, 0.30 mmol) and AsFc2Ph (150 mg,0.29 mmol) in octane (20 mL) was refluxed for 3.5 h. TLC revealed theformation of more than ten products, while 1 H NMR spectroscopy revealedthe presence of one major and many minor hydride resonances. Thesolvent was removed in vacuo and the residue was chromatographed onsilica with 4/1 petroleum ether/CH2C12 as eluent. The first yellow band(5%) was identified as a mixture of unreacted 0s3(C0)12 and ferrocene. Thesixth yellow and fourteenth pink bands contained traces of unidentifiedmixtures. The other bands in the order of elution contained complexes(312) (4%), (313) (4%), (314) (2%), (315) (20%), (316) (5%), (317) (8%),(318) (10%), (319) (6%), (320) (2%), and (321) (12%), respectively. Crystalsof (312), (313), (317), and (318), obtained from 3/1 hexane/CH2C12solutions, await analysis. Crystals of (315) suitable for X-ray structuredetermination were obtained from a 2/1 petroleum ether/CH2C12 solution.(312), green solid. 1 H NMR (300 MHz): 8 7.53-7.47 (m, 2H), 7.43-7.33(m, 3H), 5.06 (d, 2H, J=2.4), 4.14 (s, 511), 4.05 (t, 1H, J=2.4). Mass spectrum(FAB): m/e 1158 (P+, base peak), 1130, 1101, 1073, 1045, 1016, 990, 961,935, 905. Anal. calcd. for C25H13AsFe090s3: C, 25.91; H, 1.13. Found: C,26.34; H, 1.28.(313), orange solid. 1 H NMR (300 MHz): 8 7.63 (m, 2H), 7.10 (m, 2H),4.53-4.48 (m, 4H), 4.23 (s, 5H). Mass spectrum (FAB): m/e 1158 (P+, basepeak), 1131, 1101, 1074, 1045, 1016, 991, 960, 934, 906. Anal. calcd. forC25H13AsFe090s3: C, 25.91; H, 1.13. Found: C, 26.07; H, 1.16.(314), greenish orange solid. 1 H NMR (300 MHz): 8 4.47 (m, 4H), 4.32(m, 4H). Anal. found: C, 20.68; H, 0.95.171(315), orange solid. 1 H NMR (300 MHz): 6 9.2-8.5 (broad, 2H), 6.9-6.4(broad, 2H), 4.4-3.7 (broad overlapping multiplets with two C5H5 singletssuperimposed, 18H), -16.42 (s, 1H). Mass spectrum (FAB): m/e 1344 (P+,base peak), 1316, 1288, 1260, 1232, 1204, 1176, 1148, 1120, 1092. Anal.calcd. for C35H23AsFe2O9Os3: C, 31.26; H, 1.72. Found: C, 31.35; H, 1.76.(316), yellow solid. 1 H NMR (300 MHz): 6 7.52 (m, 2H), 7.31 (m, 3H),4.46 (bm, 4H), 4.23 (bm, 211), 4.17 (s, 10H), 4.03 (bm, 2H). Mass spectrum(FAB): m/e 1402 (P+), 1374, 1346 (base peak), 1319, 1290, 1262, 1233,1205, 1177, 1149, 1122, 1092. Anal. calcd. for C37H23AsFe20110s3: C, 31.72;H, 1.65. Found: C, 31.47; H, 1.58.(317), orange solid. 1 H NMR (300 MHz): 8 6.94 (q, 2H), 6.69 (q, 2H),4.64 (m, 2H), 4.45 (m, 2H), 4.21 (s, 5H), 4.11 (s, 5H), 4.08 (m, 2H), 3.57 (m,2H), -15.31 (s, 111). Mass spectrum (FAB): m/e 1072 (P+, base peak), 1044,1016, 987, 959, 931, 903. Anal. calcd. for C32H23AsFe2O6Os2: C, 35.90; H,2.17. Found: C, 35.76; H, 2.08.(318), orange solid. 1 H NMR (300 MHz): 8 7.78 (m, 1H), 7.66 (m, 1H),7.61 (m, 1H), 7.45 (m, 2H), 5.17 (m, 1H), 5.08 (m, 1H), 4.77 (m, 1H), 4.75(m, 1H), 4.63 (m, 1H), 4.61 (m, 1H), 4.52 (m, 1H), 4.42 (m, 2H), 4.31 (m,111), 4.02 (s, 5H), 3.59 (m, 1H), 3.28 (m, 1H), -12.24 (s, 1H), -16.79 (s, 1H).Mass spectrum (FAB): m/e 1318 (P+, base peak), 1290, 1262, 1234, 1205,1177, 1149, 1121, 1093. Anal. calcd. for C34H23AsFe2O8Os3: C, 31.01; H,1.76. Found: C, 30.68; H, 1.88.(319), pink solid. 1 H NMR (300 MHz): 6 6.36 (m, 1H), 5.77 (m, 1H),5.60 (m, 1H), 5.20 (m, 1H), 4.57 (m, 1H), 4.53 (m, 1H), 4.35 (s, 5H), 4.14 (m,1H), 3.61 (m, 1H). Anal. found: C, 24.17; H, 1.26.(320), orange solid. 1 H NMR (300 MHz): 8 7.38 (m, 2H), 7.22-7.11 (m,311), 6.72 (m, 1H), 6.39 (m, 211), 6.26 (m, 1H), 4.88 (m, 111), 4.79 (m, 1H),1724.53-4.46 (m, 3H), 4.45-4.39 (m, 2H), 4.35-4.29 (m, 2H+2H), 4.27 (s, 5H),4.23 •(s, 5H), 4.16 (s, 10H), 4.06 (m, 2H), 3.88 (m, 1H), 3.75 (m, 1H), 3.52 (m,1H), -14.23 (s, 1H). Mass spectrum (FAB): m/e 1838 (P+, base peak), 1810,1782, 1754, 1726, 1697, 1669, 1641.(321), orange solid. 1H NMR (300 MHz): 8 7.82 (m, 1H), 7.48-7.28 (m,3H), 4.88 (m, 1H), 4.82 (m, 1H), 4.47 (m, 1H), 4.43 (m, 1H), 4.32 (m, 2H),4.23 (m, 1H), 4.18 (s, 5H), 4.08 (m, 1H), 4.04 (m, 1H), 3.96 (m, 1H), 3.94 (m,1H), 3.91 (m, 1H), 3.87 (s, 5H), 3.82 (m, 1H), 3.79 (m, 1H), 3.73 (m, 1H),3.60 (m, 1H). Mass spectrum (FAB): m/e 1546 (P+, base peak), 1490, 1462,1434, 1406, 1377.3.5.16 Pyrolysis of 0s3(C0)10[Fe(PiPr2)2]A solution of 0s3(C0)10[Fe(P 1Pr2)2] (150 mg, 0.12 mmol) in octane (80mL) was refluxed for 7.5 h. The solvent was removed in vacuo, and the 31 Pand 1 H NMR spectra, and 31 P- 31 P COSY spectrum of the reaction mixturewere recorded. The solid residue was chromatographed on silica by using3/1 petroleum ether/CH2C12 as eluent. The first to eleventh bandscontained complexes^(322) (20%),^(323)^(10%), (324) (10%), (325) (6%),(326) (10%), (327) (1%), (328) (1%), (329) (8%), (330) (15%), (331) (3%),and (332) (1%), respectively, in the order of elution. Crystals of (323),(325), (326), (329), and (330) for X-ray structure analyses were obtainedby slow evaporation of the collected bands. Crystals of (322), obtained byslow evaporation of its solution in 1/1 hexane/CH2C12, await analysis.(322), yellow solid. 31 P NMR (121.4 MHz): 8 76.3, 40.4, J=2.8. 1 H NMR(300 MHz): 8 4.72 (m, 1H), 4.43 (m, 2H), 4.34 (m, 2H), 4.06 (m, 1H), 3.84(m, 1H), 2.75 (bm, 2H), 2.20 (bm, 1H), 1.88 (d, 311, J=20.8), 1.76 (d, 3H,J=21.0), 1.66 (dd, 31-1), 1.49 (dd, 3H), 1.35 (dd, 3H), 1.22 (dd, 3H), -17.66173(ddd, 1H, J1=17.7, J2=11.4, J3=1.2), -19.16 (ddd, 1H, J1=27.6, J2=5.4, J3=1.2).Mass spectrum (FAB): m/e 1170 (P+, base peak), 1142, 1114, 1086, 1058,1030, 974, 874, 856, 842, 832, 818. Anal. calcd. for C27H3oFe080s3P2: C,27.70; H, 2.58. Found: C, 28.03; H, 2.71.(323), yellow solid. 31p NMR (121.4 MHz): 6 18.0, 16.2, J=19.3. 1 HNMR (200 MHz): 8 4.41 (m, 1H), 4.28 (m, 3H), 4.21 (m, 1H), 4.13 (m, 2H),4.00 (m, 1H), 2.87 (m, 1H), 2.64 (m, 1H), 2.49 (m, 1H), 1.65 (dd, 3H, J1=17.6,J2=7.1), 1.32 (dd, 3H, J1=16.7, J2=6.2 ), 1.30 (dd, 3H, J1=15.7, J2=7.6), 1.25(dd, 3H, Ji=16.2, J2=7.1), 0.97 (dd, 3H, J1=17.1, J2=7.1), 0.74 (dd, 3H, J1=11.9,J2=6.7), -17.98 (dd, 111, J1=18.0, J2=8.4). Mass spectrum (FAB): m/e 1198(P+, base peak), 1170, 1142, 1126, 1114, 1099, 1086, 1070, 1058, 1042,1030, 1002, 974, 960, 946, 930, 903, 887, 860, 818. Anal. calcd. forC28H30FeO9 Os3P2: C, 28.05; H, 2.52. Found: C, 28.27; H, 2.66.(324), yellow solid. 31 P NMR (81.0 MHz): 6 28.2, 6.0, J=12.7. 1 H NMR(200 MHz): 8 4.46 (m, 2H), 4.28 (m, 3H), 4.17 (m, 1H), 3.98 (m, 1H), 2.50(m, 1H), 2.34 (m, 1H), 2.20 (m, 1H), 1.57(dd, 3H), 1.47 (dd, 3H), 1.39 (dd,3H), 1.35 (dd, 3H), 1.18 (dd, 3H), 1.11 (dd, 3H), -17.84 (dd, 1H, J1=J2=11.3),-18.92 (dd, 111, J1=22.2, J2=6.1). Mass spectrum (FAB): m/e 1170 (P+, basepeak), 1142, 1128, 1114, 1086, 1072, 1058, 1044, 1030, 1016, 1002, 988,960, 932, 918, 890, 876, 844, 832, 818. Anal. calcd. for C27H30Fe080s3P2: C,27.70; H, 2.58. Found: C, 27.81; H, 2.82.(325), orange solid. 31 P NMR (121.4 MHz): 8 -5.3. 1 H NMR (300 MHz):8 6.26 (s, 2H), 5.50 (s, 2H), 2.90 (m, 2H), 2.35 (m, 2H), 1.40 (m, 12H), 1.26(m, 12H), -17.36 (d, 2H, J=27.9), -19.54 (d, 2H, J=12.6). Anal. calcd. forC38H36FeO16Os6P2: C, 22.73; H, 1.81. Found: C, 22.87; H, 1.89.(326), yellow solid. 31 P NMR (121.4 MHz): 6 70.1, 22.6, J=18.7. 1 11NMR (500 MHz): 6 4.68 (m, 1H), 4.52 (m, 1H), 4.40 (m, 1H), 4.35 (m, 1H),1744.30 (m, 1H), 3.97 (m, 1H), 3.74 (m, 1H), 2.71 (m, 1H), 2.59 (m, 1H), 2.50(m, 1H), 1.59 (dd, 3H), 1.43 (dd, 3H), 1.38 (dd, 3H), 1.18 (dd, 3H), 1.05 (dd,3H), 0.83 (dd, 3H), -15.94 (dd, 1H, J1=18.2, J2=6.3), -17.27 (dd, 1H, Ji=27.0,J2=10.8). Mass spectrum (FAB): m/e 1170 (P+, base peak), 1142, 1128,1114, 1086, 1072, 1058, 1044, 1030, 1016, 1002, 988, 974, 960, 946, 932,918, 890, 876, 858, 844, 832, 818. Anal. calcd. for C27H30Fe080s3P2: C,27.70; H, 2.58. Found: C, 27.94; H, 2.65.(327), orange solid. 31 p NMR (121.4 MHz): 8 0.0. 1 H NMR (200 MHz)(hydrides only): 8 -16.91 (d, J=25.8), -19.05 (d, J=12.8).(328), orange solid. 31 P NMR (121.4 MHz): 6 2.7. 1 H NMR (200 MHz)(hydrides only): 8 -16.78 (d, J=25.0), -18.91 (d, J=11.9).(329), orange solid. 31 P NMR (81.0 MHz): 6 268.3, 16.5, J<1. 1 H NMR(400 MHz): 6 5.26 (m, 1H), 5.21 (m, 11-1), 4.93 (m, 1H), 4.89 (m, 1H), 3.88(m, 1H), 3.69 (m, 1H, CHMe2), 3.56 (m, 1H), 3.28 (m, 1H), 2.92 (m, 1H), 2.61(m, 1H, CHMe2), 2.12 (m, 1H, CHMe2), 1.89 (dd, 3H, J1=15.9, J2=6.9), 1.83(dd, 3H, J1=16.2, J2=7.0), 1.57 (dd, 3H, J1=7.4, J2=2.5), 1.51 (dd, 3H, J1=12.9,J2=7.6), 1.49 (dd, 3H, J1=13.0, J2=7.2), 1.40 (dd, 3H, J1=18.5, J2=7.4), -21.92(dd, 1H, J1=13.9, J2=7.6). Mass spectrum (FAB): m/e 1142 (P+, base peak),1114, 1086, 1072, 1058,1044, 1030, 1016, 1002, 988, 974, 960, 946, 918,886, 872, 858, 844, 830, 816. Anal. calcd. for C26H30Fe070s3P2: C, 27.32; H,2.65. Found: C, 27.49; H, 2.71.(330), pink solid. 31p NMR (121.4 MHz): 6 59.2, 19.2, J=3.8. 1 H NMR(300 MHz): 8 4.62 (m, 1H), 4.43 (m, 2H), 4.37 (m, 1H), 4.28 (m, 2H), 4.16(m, 1H), 3.97 (m, 1H), 3.08 (m, 1H), 2.58 (m, 3H), 2.33 (m, 11-1), 2.23 (m,1H), 1.56 (dd, 3H), 1.45 (dd, 3H), 1.28 (dd, 3H), 1.25 (dd, 3H), 1.15 (dd, 3H),0.88 (dd, 3H), 0.67 (dd, 3H), -13.60 (dd, 1H, J1=7.5, J2=6.0). Mass spectrum(FAB): m/e 1240 (P+, base peak), 1212, 1184, 1156, 1128, 1100, 1082,1751068, 1054, 1040, 1026, 1012, 984, 956, 942, 928, 914, 886, 872, 858,844, 830, 816, 788. Anal. calcd. for C31,5H38C1Fe090s3P2, (330)•0.5CH2C12: C,29.46; H, 2.98. Found: C, 29.66; H, 3.09.(331), pink solid. 31 P NMR (121.4 MHz): 8 51.0, 18.7, J=3.6. 1 H NMR(300 MHz): 8 4.67 (m, 1H), 4.51 (m, 1H), 4.46 (m, 1H), 4.32 (m, 1H), 4.27(m, 2H), 4.08 (m, 1H), 3.91 (m, 1H), 3.00 (m, 1H), 2.60 (m, 2H), 2.52 (m,1H), 2.36 (m, 1H), 2.25 (m, 1H), 1.67 (dd, 3H), 1.58 (dd, 3H), 1.38 (dd, 3H),1.26 (dd, 3H), 1.14 (dd, 3H), 0.97 (dd, 3H), 0.75 (dd, 3H), -13.57 (dd, 1H,J1=7.8, J2=6.0). Mass spectrum (FAB): m/e 1240 (P+), 1212 (base peak),1184, 1156, 1128, 1114, 1100, 1082, 1068, 1054, 1040, 1026, 1012, 984,956, 928, 914, 872, 858, 844, 816, 788.(332), yellow solid. 31 P NMR (121.4 MHz): 8 54.2, 9.3, J=9.0. 1 H NMR(300 MHz): 8 4.86 (m, 2H), 4.57 (m, 1H), 4.34 (m, 1H), 4.26 (m, 1H), 3.88(m, 111), 3.41 (m, 1H), 2.94 (m, 1H, CHMe2), 2.88 (m, 1H, CHMe2), 2.46 (m,1H, CHMe2), 2.41 (m, 1H, CHMe2), 1.67-1.20 (m, very complex, 21H), 0.94(dd, 311), -16.70 (dd, 111, J1=J2=12.1). Mass spectrum (FAB): m/e 1212 (P+,base peak), 1184, 1156, 1142, 1128, 1114, 1100, 1086, 1072, 1058, 1044,1030, 1016, 988, 960, 946, 932, 918, 890, 862, 848, 834, 820.3.5.17 Pyrolysis of (0s3(C0)11)2[Fe(P iPr2)2]A solution of {0s3(C0)11)2[Fc s (P 1Pr2)2] (50 mg, 0.023 mmol) in octane(20 mL) was refluxed for 2.5 h. TLC, 31 P, and 1 H NMR spectroscopyrevealed the formation of many complexes including (325), (327), and(328). The solvent was removed in vacuo and the residue waschromatographed on silica with 3/1 petroleum ether/CH2C12 as eluent. Onlythe third band (15%) was identified to be complex (325). 3 1 P NMR (121.4MHz): 8 -5.3. 1 H NMR (300 MHz): 8 6.26 (s, 2H), 5.50 (s, 2H), 2.89 (bm, 2H),1762.34 (bm, 2H), 1.40 (bm, 12H), 1.26 (bm, 12H), -17.34 (d, 2H, J=27.9), -19.52 (d, 2H, J=12.6). Anal. calcd. for C381-136Fe0160s6P2: C, 22.73; H, 1.81.Found: C, 23.05; H, 1.92.3.5.18 Pyrolysis of 0s3(CO)12 with P(1-Cio117)3A solution of 0s3(CO)12 (180 mg, 0.19 mmol) and P(1-C10117)3 (80 mg,0.19 mmol) in octane (30 mL) was refluxed for 24 h. TLC revealed thepresence of more than eight products. 31 P NMR spectroscopy revealedthree major resonances at 51.1, 42.4, and 30.9 ppm, and a number ofminor ones. The reaction solvent was removed in vacuo and the residuewas chromatographed on florisil with 3/1 petroleum ether/CH2C12 aseluent. The first band contained unreacted 0s3(C0)12 (3%) identified by TLCand micro-analysis. The second band contained traces of an unidentifiedmixture. The third (2%) and last (5%) bands were characterized only by 1 Hand 31 P NMR spectroscopy. The fourth, fifth, and sixth bands containedcomplexes (333) (35%), (334) (30%), and (335) (10%), respectively.The third band, yellow solid. 31 13 NMR (121.4 MHz): 6 79.2. 1 H NMR(200 MHz): 8 8.16 (m), 8.10-7.90 (m), 7.85-7.00 (m), -20.53 (s, 1H).(333), yellow solid. 31 P NMR (121.4 MHz): 8 30.9. 1 H NMR (200 MHz):5. 8.86 (m, 2H), 8.1-6.8 (m, 17H), -17.59 (d, 1H, J=5.6), -21.47 (d, 1H,J=30.8). Mass spectrum (FAB): m/e 1208 (P+, base peak), 1180, 1152,1124, 1096, 1068, 1039, 1011, 983, 856, 730. Anal. calcd. forC381121080s3P: C, 37.81; H, 1.75. Found: C, 37.89; H, 1.79.(334), brown solid. 31 P NMR (121.4 MHz): 6 51.1. 1 H NMR (200 MHz):8 8.3-6.8 (m), -18.53 (d, J=37.7, satellite, hi-osi=44.0, JH-0s2=31.2). Massspectrum (FAB): m/e 1236 (P+, base peak), 1208, 1181, 1151, 1124, 1095,1067, 1039, 1011, 984, 855, 731. Anal. calcd. for C39H21O9Os3P: C, 37.92; H,1771.71. Found: C, 37.99; H, 1.84.(335), orange solid. 31 P NMR (121.4 MHz): 8 42.3. 1 H NMR (200 MHz):5 8.6 (m), 8.2-7.7 (m), 7.6-6.8 (m). Mass spectrum (FAB): m/e 1292 (P+),1264, 1236, 1208 (base peak), 1181, 1153, 1125, 1096, 1067, 1039, 1011,984, 856. Anal. calcd. for C41H210110s3P: C, 38.14; H, 1.64. Found: C, 38.00;H, 1.87.The last band, yellow solid. 31 P NMR (121.4 MHz): 8 41.9. 1 H NMR(200 MHz): 8 8.63 (d, 1H), 8.02 (m, 1H), 7.90 (d, 1H), 7.44 (t, 1H), 7.30 (m,4H). Anal. found: C, 41.37; H, 2.32.3.5.19 Pyrolysis of 0s3(C0)12 with As(1-C101-17)3A solution of 0s3(C0)12 (200 mg, 0.22 mmol) and As(1-C1oll7)3 (90mg, 0.20 mmol) in octane (40 mL) was refluxed for 25 h. TLC revealed thepresence of at least ten products, while 1 H NMR spectroscopy showed onlytwo major hydride resonances at -17.69 and -21.65 ppm. The reactionsolvent was removed in vacuo and the residue was chromatographed onsilica with 4/1 petroleum ether/CH2C12 as eluent. The first band (5%)contained a mixture of four complexes including (336), being yellow, pink,pink, and orange in colour as revealed by TLC. Naphthalene was alsopresent in the solution. The major second band (65%) contained complex(336). The third band (8%) contained a mixture of (336) and a pinkcomplex. The fourth band (5%) contained a yellow complex. The fifth band(3%) contained a yellow complex. The other bands were not eluted. Crystalsof (336) suitable for X-ray structure analysis were obtained from a 2/1hexane/CH2C12 solution.(336), yellow solid. 1 H NMR (400 MHz): 5 8.51 (m,1H), 8.45 (m,1H),8.20 (m,1H), 8.03 (m, 2H), 7.93-7.82 (m, 3H), 7.79 (m,1H), 7.70 (m,1H),1787.50-7.38 (m, 5H), 7.38-7.31 (m, 3H), 7.27 (m,1H), -17.69 (s, 1H, Ossatellite, J}{_o s 1=27.6, hi-os2=43.8), -21.65 (s,1H, Os satellite, JH-Os1=28 .0, J1-1-0s2=45.6). Mass spectrum (FAB): m/e 1252 (P+, base peak), 1224, 1196,1167, 1138, 1110, 1094, 1080, 1066, 1052, 1037, 1024, 982, 969, 954,940, 928, 912, 898, 884, 870, 856, 843, 829, 703. Anal. calcd. forC381-121As080s3: C, 36.48; H, 1.69. Found: C, 36.55; H, 1.74.The fourth band, mass spectrum (FAB): m/e 1452 (P+), 1424, 1396,1368, 1312, 1284, 1256, 1240, 1224, 1182, 1154, 1126, 1096 (base peak),970, 880, 850.The fifth band, mass spectrum (FAB): m/e 1554 (P+, base peak),1524, 1478, 1370, 1334, 1312, 1223, 1092, 981, 908, 880, 852.3.6 Pyrolysis of Ru3 ComplexesThe pyrolyses of Ru3(CO)11L (L=PFcPh2 or PFc2Ph) and Ru3(CO)10(PFcPh2)2 were studied previously [315]. In the first two reactions nocomplexes were firmly characterized [315], and in the last reaction onlyone complex (344) was characterized [119].3.6.1 Pyrolysis of Ru3(C0)11(PFcPh2) [315](a) in cyclohexane for 1 hA solution of Ru3(CO)11(PFcPh2) (150 mg, 0.15 mmol) in cyclohexane(50 mL) was refluxed for 1 h. 31 P NMR spectroscopy revealed four majorresonances at 408.1, 387.8, 149.6, lnd 112.7 ppm. The solvent was removed179in vacuo and the residue was chromatographed on silica with 3/1 petroleumether/CH2C12 as eluent. The first yellow band contained Ru3(CO)12 (2%)identified by TLC and mass spectrometry. The second orange band containedunreacted starting material (5%) identified by TLC, 1 H, and 31 P NMRspectroscopy. The third band contained complex (337) (20%). The fourthpink band contained complex (338) (to be described in the next section) (2%)identified by TLC, 31 P, and 1 H NMR spectroscopy. The fifth band containedcomplex (339) (20%). The sixth band contained complex (340) (5%). Onemajor compound (-20%) showing a 31 13 NMR resonance at 112.7 ppm was notfound in any collected bands. Crystals of (339), obtained from a 2/1hexane/CH2C12 solution, await analysis.(337), orange solid. 31 P NMR (121.4 MHz): 8 387.8. 1 H NMR (300 MHz):8 7.62 (m, 2H), 7.12 (m, 2H), 4.62-4.56 (m, 4H), 4.28 (s, 5H). Mass spectrum(FAB): m/e 847 (Pt), 819, 791, 764, 735, 709 (base peak). Anal. calcd. forC25H13FeO9PRu3: C, 35.41; H, 1.54. Found: C, 35.73; H, 1.64.(339), orange solid. 3 1 P NMR (121.4 MHz): 8 408.1. 1 H NMR (300 MHz):8 6.99 (m, 211), 6.52 (m, 211), 4.53 (m, 211), 4.36 (m, 2H), 4.21 (s, 5H). Massspectrum (FAB): m/e 1004 (P+), 977, 950, 921 (base peak), 895, 866, 839,809, 781, 753, 725, 694. Anal. calcd. for C271113Fe0 1PRu.4: C, 32.26; H, 1.30.Found: C, 32.48; H, 1.51.(340), yellow solid. 31 P NMR (121.4 MHz): 5 149.5. 1 H NMR (300 MHz):8 8.15 (t, 1H), 7.58-7.47 (m, 2H), 7.37 (m, 1H), 4.81 (m, 1H), 4.68 (m, 1H),4.52 (m, 111), 4.47 (m, 1H), 4.08 (s, 5H). Mass spectrum (FAB): m/e 720 (Pt),692, 664 (base peak), 636, 608, 580, 552, 523, 509, 495. Anal. calcd. forC24H13FeO8PRu2: C, 40.10; H, 1.82. Found: C, 40.23; H, 1.89.(b) in cyclohexane for 3 hA solution of Ru3(CO)11(PFcPh2) (200 mg, 0.20 mmol) in cyclohexane(100 mL) was refluxed for 3 h. 31 P NMR spectroscopy revealed (339) and(340) as major products and some new compounds. The solvent wasremoved in vacuo and the residue was chromatographed on silica with 3/1petroleum ether/CH2C12 as eluent. The first yellow band contained Ru3(CO)12(1%). The second band contained (337) (20%) identified by 31 P and 1 H NMRspectroscopy. The third band contained complex (341) (8%). The fourth bandcontained (338) (3%) identified by TLC, 31 P, and 1 H NMR spectroscopy. Thefifth band contained (339) (25%) identified by 31 P and 1 H NMR spectroscopy.The sixth band contained complex (342) (12%). The seventh and eighthbands contained small amount of mixtures. The ninth band (2%) contained acomplex mixture including complex (340). The tenth band containedcomplex (343) (4%). Crystals of (342) were obtained from a 1/1hexane/CH2C12 solution.(341), orange solid. 31p NMR (121.4 MHz): 3 415.3. 1 H NMR (300 MHz):8 5.63 (m, 1H), 5.42 (m, 1H), 4.78-4.72 (m, 2H), 4.68-4.60 (m, 4H), 4.29 (s,5H). Mass spectrum (FAB): m/e 1163 (P+, base peak), 1135, 1107, 1080,1051, 1022, 994, 967, 938, 909, 881, 854.(342), red solid. 31 P NMR (121.4 MHz): 6 390 (broad), 162.2 (d, J=17.5).1H NMR (300 MHz): 3 8.22 (m, 1H), 7.82 (m, 1H), 7.60 (m, 1H), 7.52 (m, 1H),6.95 (m, 1H), 6.88 (m, 1H), 5.90 (m, 1H), 5.85 (m, 1H), 4.72 (m, 2H), 4.65 (m,1H), 4.60 (m, 1H), 4.55 (m, 1H), 4.41 (m+s, 1+5H), 4.34 (m, 1H), 4.18 (s, 5H),3.98 (m, 1H). Mass spectrum (FAB): m/e 1398 (P+), 1369, 1341, 1313, 1285,1257, 1228, 1201, 1086 (base peak). Anal. calcd. for C44H28C12Fe2011P2Ru5,(342)•CH2C12: C, 35.65; H, 1.90. Found: C, 35.26; H, 1.81.181The seventh band, red solid. 31 P NMR (121.4 MHz): 8 450.6; 420.6(small); 389.8, 162.2 (342). TLC: 3 spots.The eighth band, orange solid. 31p NMR (121.4 MHz): 8 387.2, 192.8,J=73.4; 40.7 TLC: 3 spots.The ninth band, red solid. 31 P NMR (121.4 MHz): 8 423.5; 415.3; 239.9;149.5 (340). TLC: 4 spots.(343), red solid. 31 P NMR (121.4 MHz): 8 410.5, 275.0, J=30.1. 1 H NMR(300 MHz): 8 8.12 (m, 1H), 7.72 (m, 1H), 7.55 (m, 211), 7.41 (m, 111), 6.71 (m,1H), 6.64 (m, 2H), 4.55 (m, 2H), 4.36 (m, 1H), 4.23 (m, 1H), 4.13 (m, 1H), 4.07(s, 5H), 4.00 (m, 1H), 3.97 (s, 5H), 3.88 (m, 11-1), 3.42 (m, 1H). Mass spectrum(FAB): m/e 1268 (P+, base peak), 1240, 1212, 1185, 1157, 1118, 1090, 1062,1034, 1016, 984.(c) in hexanesA solution of Ru3(CO)11(PFcPh2) (50 mg, 0.05 mmol) in hexanes (50mL) was refluxed for 14 h. 31 P NMR spectroscopy revealed complexes (339)and (342) as the major products. The solvent was removed in vacuo and theresidue was chromatographed on silica with 3/1 petroleum ether/CH2C12 aseluent. The first pink band contained an unidentified compound (2%). Thesecond orange band was identified to be (339) (20%) by 31 13 and 1 H NMRspectroscopy. The third red band contained (342) (8%) identified by TLC and31 P NMR spectroscopy. A number of small bands were not collected.Complexes (337), (341), and (343) were probably present in the mixture. A31 P NMR resonance at 434.5 ppm corresponds to a complex previouslyunobserved.3.6.2 Pyrolysis of Ru3(C0)10(PFcPh2)2 [119, 315](a) in cyclohexaneA solution of Ru3(C0)10(PFcPh2)2 (30 mg, 0.020 mmol) in cyclohexane(30 mL) was refluxed for 70 min. The solvent was removed under reducedpressure and the residue was chromatographed on silica with 3/1 petroleumether/diethyl ether as eluent. Three bands were collected but the seconddark yellow and third yellow ones were not characterized. The first pinkband appeared pure by TLC in various combinations of petroleumether/diethyl ether solvent, but TLC in 4/1 petroleum ether/CH2C12 revealedthat indeed it contained two pink compounds. 31 P NMR spectroscopyrevealed the presence of (338) and (344). The 1 H NMR spectrum also showsextra signals besides those for (344) which has been previously described[119].(b) in hexanesA solution of Ru3(CO)10(PFcPh2)2 (40 mg, 0.030 mmol) in hexanes (100mL) was refluxed for 20 h. TLC indicated the formation of (338) and (344) at1.5 h. 31 P NMR spectroscopy revealed complexes (338) and (344) as themajor products formed. Their spectroscopic and analytical data appear in thenext section.3.6.3 Pyrolysis of Ru3(CO)9(PFcPh2)3(a) in hexanesA solution of Ru3(CO)9(PFcPh2)3 (50 mg, 0.030 mmol) in hexanes (50183mL) was refluxed for 15 h after which the solvent was removed in vacuo.Both 31 P and 1 H NMR spectroscopy, and TLC showed little reaction.(b) in cyclohexaneA solution of Ru3(CO)9(PFcPh2)3 (150 mg, 0.090 mmol) in cyclohexane(70 mL) was refluxed for 13 h. TLC and 31 P NMR spectroscopy revealed thepresence of five major products. The solvent was removed in vacuo and theresidue was chromatographed on silica with 2/1 petroleum ether/CH2C12 aseluent. The first purple band contained complex (338) (25%). The secondband contained complex (344) (18%). The third band (5%) contained amixture of an unidentified complex and the starting material. The fourthband contained complex (345) (8%). The fifth band (3%) contained a mixtureof four complexes. The last band (15%) contained complexes (346) and (347).Crystals of (344) were obtained from a 3/1 hexane/CH2C12 solution.(338), purple solid. 31 P NMR (121.4 MHz): 8 236.8. 1 H NMR (300 MHz):5 7.82 (m, 2H), 7.60-7.46 (m, 6H), 7.34 (m, 2H), 6.53 (m, 2H), 6.10 (m, 2H),4.54 (m, 2H), 4.39 (m, 2H), 4.27 (s, 10H), 4.23 (m, 2H), 3.94 (m, 2H). Massspectrum (FAB): m/e 1162 (P+, base peak), 1108, 1078, 1051, 1022, 995,966, 887, 864, 810. Anal. calcd. for C45H32Fe2O7P2Ru3: C, 46.53; H, 2.78.Found: C, 46.74; H, 2.94.(344), purple solid. 31 P NMR (121.4 MHz): 8 272.5, 208.5, J=199.6. 1 HNMR (300 MHz): 8 7.98 (m, 2H), 7.81 (m, 2H), 7.74 (m, 1H), 7.58-7.46 (m,4H), 7.23 (m, 1H), 7.00 (m, 1H), 6.61 (m, 1H), 6.51 (m, 1H), 6.40 (m, 1H), 4.58(m, 1H), 4.45 (m, 2H), 4.32 (s, 5H), 4.13 (rn, 1H), 4.03 (m+s, 1+5H), 3.77 (m,1H), 3.71 (m, 1H), 2.86 (m, 1H). Mass spectrum (FAB): m/e 1163 (P+), 1106(base peak), 1079, 1050, 1023, 994, 967, 888, 821, 810. Anal. calcd. forC45H32Fe2O7P2Ru3: C, 46.53; H, 2.78. Found: C, 46.81; H, 2.89. The spectro-1 8 4scopic data agree with those in the literature.The third band, dark red solid. 3 IP NMR (121.4 MHz): 8 250.9; 29.0.TLC: 2 spots with one being the starting material Ru3(C0)9(PFcPh2)3.(345), orange solid. 31 P NMR (121.4 MHz): 8 265.1, 208.3, J=201.6. 1 HNMR (300 MHz): 8 8.11 (m, 2H), 7.68 (m, 2H), 7.55 (m, 1H), 7.42 (m, 3H), 7.30(m, 3H), 7.22 (m, 1H), 7.04 (m, 1H), 6.85 (m, 1H), 4.68 (m, 1H), 4.48 (m, 2H),4.34 (s, 5H), 4.20 (m, 1H), 4.11 (m, 1H), 4.05 (s, 5H), 3.88 (m, 1H), 3.82 (m,111), 3.57 (m, 1H). Mass spectrum (FAB): m/e 1191^(P+),^1163, 1135, 1107,1079 (base peak),^1051,^1022, 994, 966, 887.The fifth band, dark red solid. 3IP NMR (121.4 MHz): 8 268.0, 30.8,J=166.7; 265.0, 28.8, J=153.2.^1 H NMR (300 MHz): 8 8.40, 8.15-7.95, 7.75-7.05, 6.62, 6.45, 4.55-3.72 (many peaks). Mass spectrum (EI, 200°C): m/e1025 (P+), 997, 970 (base peak), 942, 862, 788, 760, 680, 651. TLC: 2 majorand 2 minor spots.(346), pink solid. 31 P NMR (202.5 MHz): 6 245.1, 240.0, 24.3, JAB=191.0,hx=18.0, JAX<2.0. (347), pink solid. 31 P NMR (202.5 MHz): 6 235.3, 237.8,26.5, JAB=205.8, JBX=12.6, JAX<2.0. The 1 H NMR (300 MHz) spectrum of themixture of (346) and (347) is shown in Figure 5.12. Mass spectrum of themixture (FAB): m/e 1503 (Pt, base peak), 1475, 1447, 1418, 1390, 1361,1333, 962, 890. Anal. calcd. for C66H51Fe306P3Ru3: C, 52.71; H, 3.42. Found: C,52.48; H, 3.39.3.6.4 Pyrolysis of Ru3(C0)11(PFc2Ph) [315](a) in hexanesA solution of Ru3(CO)1 i(PFc2Ph) (200 mg, 0.18 mmol) in hexanes (100185mL) was refluxed for 15 h. 31 P NMR spectroscopy revealed the presence offour major resonances at 408.2, 377.8, 364.4, and 24.6 ppm, and threeminor ones at 373.4, 328.9, and 15.8 ppm. The solvent was removed invacuo, and the residue was chromatographed on silica with 2/1 petroleumether/CH2C12 as eluent. The first, third, fourth, and sixth bands containedcomplexes (348) (15%), (339) (10%), (349) (25%), and (350) (20%),respectively. The second band (6%) contained a mixture of twounidentified complexes and the starting material. The fifth band containedtraces of a green and an orange compound which were not identified.(348), orange solid. 31 P NMR (121.4 MHz): 6 364.4. 1 H NMR (300MHz): 6 5.68 (m, 1H), 4.80 (s, 5H), 4.39 (m, 2H), 4.17 (m, 2H), 4.08 (s, 5H),3.87 (m, 2H). Mass spectrum (FAB): m/e 1086 (P+), 1003, 977, 951, 896,869 (base peak), 845, 816, 788, 762, 732, 704, 661, 606, 593.The second band, red solid. 31 P NMR (121.4 MHz): 8 129.1, 125.1,15.9. TLC: 3 spots.(339), orange solid. 31 P NMR (121.4 MHz): 8 408.0. 1 H NMR (300MHz): 6 7.00 (t, 2H), 6.52 (t, 2H), 4.51 (m, 2H), 4.35 (m, 2H), 4.22 (s, 5H).Mass spectrum (FAB): m/e 1006 (P+), 922 (base peak), 878, 793, 764, 737.Anal. calcd. for C271-113Fe01 1PRu4: C, 32.28; H, 1.30. Found: C, 32.54; H, 1.41.(349), pink solid. 31 P NMR (121.4 MHz): 8 377.8. 1 H NMR (300 MHz): 88.12 (m, 2H), 7.70 (m, 2H), 4.69 (m, 1H), 4.50 (m, 2H), 4.32 (s, 5H), 4.29 (m,1H), 4.07 (m, 1H), 4.00 (m, 1H), 3.73 (s, 5H), 3.21 (m, 1H), 2.33 (m, 1H).Mass spectrum (FAB): m/e 1008 (Pt), 951, 926, 896, 782 (base peak).(350), reddish orange solid. 31 P NMR (121.4 MHz): 6 24.6. 1 H NMR(300 MHz): 6 8.0 (m, 2H), 7.5 (m, 3H), 5.5 (m, 2H), 4.5 (s, 5H), 4.4-4.2 (m,3H), 4.0 (s, 5H), 3.6 (m, 1H), 3.0 (m, 1H), -15.0 (d, 1H, J=28.1). Massspectrum (FAB): m/e 1035 (P+), 1007, 979, 950, 922, 893, 864, 838 (base186peak), 809, 776. Anal. calcd. for C35H23Fe2O9PRu3: C, 40.68; H, 2.24. Found:C, 40.78; H, 2.30.(b) in cyclohexaneA solution of Ru3(C0)11(PFc2Ph) (100 mg, 0.090 mmol) in cyclohexane(50 mL) was refluxed for 6 h. 31 p NMR spectroscopy revealed similarresonances as in (a). The solvent was removed in vacuo and the residuewas chromatographed on silica with 3/1 petroleum ether/CH2C12 as eluent.The first band gave Ru3(C0)12 (2%). The second to fifth bands containedcomplexes (348) (15%), (339) (25%), (349) (15%), and (350) (20%),respectively, identified by TLC and 31 P NMR spectroscopy.The sixth bandcontained a mixture of three complexes as shown by TLC and 31 P NMRspectroscopy.(c) in tolueneA solution of Ru3(CO)1 i(PFc2Ph) (220 mg, 0.20 mmol) in toluene (40mL) was refluxed for 5 h. The solvent was removed in vacuo and theresidue was chromatographed on silica with 4/1 petroleum ether/CH2C12 aseluent. The first, second, fourth, and sixth bands contained complexes(339) (15%), (348) (25%), (349) (5%), and (350) (20%), respectively,identified by TLC and 31 P NMR spectroscopy. The third and fifth bandscontained new complexes (351) (10%) and (352) (5%), which will bedescribed in the next section, identified by TLC, 1 H, and 31 P NMRspectroscopy. The seventh band contained a mixture of three complexes asshown by TLC and 31 P NMR spectroscopy (424.5, 414.3, and 110.1 ppm).1873.6.5 Pyrolysis of Ru3(CO)12 with PFc2PhA solution of Ru3(CO)12 (256 mg, 0.40 mmol) and PFc2Ph (190 mg,0.40 mmol) in octane (50 mL) was refluxed for 3.5 h. 3 IP NMRspectroscopy revealed three major resonances at 408.0, 364.2, and 328.5ppm, two medium resonances at 418.1 and 371.6 ppm, and very minorones at 424.2, 414.3, 221.7, 141.2, 138.7, 132.6, and 110.1 ppm. 1 H NMRspectroscopy showed the absence of any hydrides. The reaction solventwas removed in vacuo, and the residue was chromatographed on aluminawith 4/1 petroleum ether/CH2C12 as eluent. The first band (2%) contained acomplex characterized only by 1 H NMR spectroscopy. The second bandcontained complex (351) (12%). The third orange band contained (339)(20%) identified by TLC, 1 H, and 31 P NMR spectroscopy. The fourth bandcontained small amount of a mixture of two complexes. The fifth bandcontained complex (352) (16%). The other bands were small and noteluted. The major complex (348) showing the 31 P NMR resonance at 364.4ppm and a new minor complex showing a 31 P NMR resonance at 371.6 ppmwere not found. Crystals of (351) suitable for an X-ray diffraction studywere obtained from a 5/1 hexane/CH2C12 solution.The first band, orange solid. 1 H NMR (300 MHz): 8 4.65 (m, 2H), 4.59(m, 211), 4.52 (s, 5H), 4.36 (m, 2H), 4.13 (s, 511), 4.05 (m, 2H).(351), red solid. 31 P NMR (121.4 MHz): 6 418.0. 1 H NMR (300 MHz): 65.28 (m, 1H), 5.18 (m, 1H), 4.80 (m, 111), 4.54 (m, 211), 4.50 (m, 1H), 4.44(m, 1H), 4.35 (m, 1H), 4.31 (s, 5H). Mass spectrum (FAB): m/e 993 (P+),966, 935, 909 (base peak), 880, 853, 826, 797, 768, 741, 683. Anal. calcd.for C26H13Fe011PRu4: C, 31.47; H, 1.32. Found: C, 31.61; H, 1.38.(352), green solid. 31 P NMR (121.4 MHz): 6 328.5. 1 H NMR (300 MHz):6 6.12 (tm, 1H), 4.97 (s, 5H), 4.35 (m, 2H), 4.22 (dm, 2H), 4.16 (s, 5H), 4.12188(m, 2H). Mass spectrum (FAB): m/e 956 (P+, base peak), 928, 900, 873,844, 816, 787, 759, 731, 702.3.6.6 Pyrolysis of Ru3(CO)12 with PEt2FcTriruthenium dodecacarbonyl (200 mg, 0.31 mmol) and PEt2Fc (75mg, 0.27 mmol) in octane was refluxed for 18 h. TLC revealed theformation of more than ten products. The solvent was removed in vacuo,and the residue was chromatographed on Florisil with 4/1 petroleumether/CH2C12 as eluent. The first yellow band contained ferrocene (2%)identified by TLC and 1 H NMR spectroscopy. The second band (5%)contained a mixture of four compounds. The third band contained complex(353) (15%). The fourth band contained complex (354) (25%). The fifthreddish orange band (10%) contained a mixture of three complexes by TLC.The sixth band contained a pure complex (10%) by TLC but was notcharacterized. Crystals of (353) and (354), obtained by slow evaporation ofthe collected bands, await analysis.The second band, yellow solid. 31 P NMR (121.4 MHz): 8 448.6, 293.4,282.5, 94.5. TLC: 4 spots.(353), orange solid. 31 P NMR (81.0 MHz): 6 370.4. 1 H NMR (200 MHz):8- 2.34 (m), 2.12 (m), 1.33 (m), 1.26 (m). Mass spectrum (FAB): m/e 1189(P+, base peak), 1159, 1133, 1025, 1077, 1046, 1017, 991, 963, 935, 906.(354), brownish red solid. 31 P NMR (81.0 MHz): 8 366.8. 1 H NMR (200MHz): 6 4.62 (s, 5H), 4.30 (s, 1H), 2.23 (m, 2H), 2.04 (m, 2H), 1.40-1.15 (m,6H). Mass spectrum (FAB): m/e 1137 (P+, base peak), 1109, 1080, 1052,1024, 995, 964, 935, 907, 879.1893.6.7 Pyrolysis of Ru3(CO)12 with PEtFc2A solution of Ru3(C0)12 (150 mg, 0.23 mmol) and PEtFc2 (110 mg,0.26 mmol) in toluene (40 mL) was refluxed for 10 h. TLC revealed thepresence of more than ten products. The solvent was removed in vacuo,and the residue was chromatographed on silica with 4/1 petroleumether/CH2C12 as eluent. The second band contained complex (355) whichwas obtained as a dark green solid. 31 F' NMR (81.0 MHz): 8 425.1. Massspectrum (FAB): m/e 995 (Pt, base peak), 967, 938, 910, 882, 854, 826,798, 770, 742. Anal. calcd. for C211113012PRu5: C, 25.38; H, 1.32. Found: C,25.57; H, 1.41.3.6.8 Pyrolysis of Ru3(C0)10[Fc'(PPh2)2](a) in cyclohexane for 4 h [120]A solution of Ru3(C0)10(bPPO (60 mg, 0.053 mmol) in cyclohexane(50 mL) was refluxed for 4 h. The solvent was removed in vacuo and theresidue was chromatographed on a silica column by using 4/1 petroleumether/CH2C12 as eluent. The first small yellow and second purple bandswere not identified. The third band contained complex (356). The fourthband contained complex (357). The fifth band contained trace of anunidentified compound and the sixth band contained complex (358). The1 H NMR data for those complexes ((356), (357), (359), and (361)) agreewith those in the literature [120] except for the hydride resonances for thecomplex (356). The 31 P NMR data were not previously recorded. Complexes(358), (360), and (362) were not previously reported.190(356), greenish orange solid. 31 13 NMR (81.0 MHz): 6 35.0, 3.5, J=4.5.1 H NMR (200 MHz): 8 7.73 (m, 2H), 7.54 (m, 2H), 7.46-7.20 (m, 15H), 7.09(m, 1H), 4.48 (m, 1H), 4.42 (m, 1H), 4.36 (m, 1H), 4.20 (m, 1H), 4.12 (m,1H), 4.00 (m, 1H), 3.92 (m, 1H), -16.47 (dd, 1H, J1=16.4, J2=12.2).(357), reddish orange solid. 31 P NMR (81.0 MHz): 8 40.6, 36.0, J=20.5.1 H NMR (200 MHz): 8 7.99 (m, 1H), 7.73 (m, 3H), 7.62 (m, 3H), 7.58-7.35(m, 10H), 7.18 (m, 1H), 6.70 (m, 1H), 4.85 (m, 1H), 4.72 (m, 1H), 4.28 (m,2H), 4.12 (m, 1H), 3.87 (m, 1H), 3.48 (m, 1H), 3.27 (m, 1H), -16.80 (dd, 1H,J1=26.4, J2=10.6).(358), red solid. 31 P NMR (81.0 MHz): 6 0.0. 1 H NMR (200 MHz): 8 7.52(m, 2}1), 7.45-7.15 (m, 16H), 6.98 (m, 2H), 4.48 (m, 2H), 4.26 (m, 4H), 4.01(m, 211).(b) in cyclohexane for 40 hA solution of Ru3(CO)10(bPPO (120 mg, 0.11 mmol) in cyclohexane(60 mL) was refluxed for 40 h. The solvent was removed in vacuo and theresidue was chromatographed on a silica column by using 4/1 petroleumether/CH2C12 as eluent. The first and second yellow bands contained smallamounts of unidentified compounds. The third band contained complex(359) (12%). The fourth band, separated from the third by repeatedchromatography, contained complex (360) (10%). The fifth band containedcomplex (361) (8%). The sixth band contained traces of an unidentifiedcompound. The seventh band contained complex (362) (4%). Thesubsequent bands contained, in the order of elution, complexes (357) (4%),(356) (55%), and (358) (2%).(359), purple solid. 31 P NMR (81.0 MHz): 6 263.9, 215.9, J=190.7. 1 HNMR (200 MHz): 6 7.92-7.80 (m, 2H), 7.50-7.20 (m, 13H), 6.45 (m, 2H), 6.26191(m, 2H), 4.51 (m, 1H), 4.44 (m, 1H), 4,37 (m, 1H), 4.19 (s, 5H), 3.75 (m, 1H).Mass spectrum (FAB): m/e 1055 (Pt, base peak), 1027, 999, 970, 943, 915,887, 859, 780, 702, 624. Anal. calcd. for C411 -128Fe07P2Ru3: C, 46.74; H, 2.68.Found: C, 46.95; H, 2.73.(360), purple solid. 31 P NMR (81.0 MHz): 8 274.9, 204.1, J=195.7. 1 HNMR (200 MHz): 8 7.78-7.50 (m, 6H), 7.40-7.20 (m, 5H), 7.08-6.86 (m, 611),6.70 (m, 2H), 4.08 (m, 1H), 4.01 (m, 1H), 3.92 (s, 5H), 3.65 (m, 1H), 2.78 (m,1H). Mass spectrum (FAB): m/e 1055 (Pt, base peak), 1027, 999, 970, 943,915, 887, 859, 780, 702, 624. Anal. calcd. for C411128Fe07P2Ru3: C, 46.74; H,2.68. Found: C, 47.03; H, 2.69.(361), orange solid. 31P NMR (81.0 MHz): 8 166.9, 111.9, J=12.8.(362), dark purple solid. 31 P NMR (81.0 MHz): 8 184.0, 128.4, J=15.0.1 14 NMR (200 MHz): 8 7.62-7.50 (m, 2H), 7.45-7.15 (m, 13H), 4.52 (m, 1H),4.40 (m, 1H), 4.28 (m, 2H), 4.14 (m, 1H), 3.88 (m, 1H), 3.24 (m, 1H). Massspectrum (FAB): m/e 1031 (P+), 1003, 975, 947 (base peak), 920, 892, 864,786, 708.3.6.9 Pyrolysis of Ru3(C0)10[Fc i (PiBuPh)2]A solution of Ru3(CO)10[Fc'(PtBuPh)2] (80 mg, 0.070 mmol) in hexanes(50 mL) was refluxed for 15 h. The solvent was removed in vacuo and theresidue was chromatographed on a silica column by using 3.5/1 petroleumether/CH2C12 as eluent. The first band (4%) contained a mixture of twocomplexes. The second band contained a yellow compound (2%). The thirdto seventh bands contained complexes (363) (15%), (364) (12%), (365)(15%), (366) (10%), and (367) (18%), respectively. Suitable crystals of (365)for an X-ray diffraction study were obtained from a toluene solution.192The first band, greenish orange solid. 31P NMR (121.4 MHz): 6 432.7,298.5, 162.9. 1 H NMR (300 MHz): 8 8.0-7.3, 5.0-4.0, 1.7-1.1. Mass spectrum(FAB): m/e 910 (P+), 881 (base peak), 851, 825, 792, 768, 741, 706, 628.The second band, yellow solid. 1 H NMR (300 MHz): 8 7.90 (m,1H),7.55 (m, 1H), 7.46 (m, 1H), 7.25 (m, 4H), 7.10 (m, 2H), 4.73 (m, 1H), 4.70(m, 1H), 4.40 (m, 11-1), 4.32 (m, 2H), 4.25 (m, 111), 4.21 (m, 1H), 4.13 (m,1H), 1.52 (d, 9H), 1.40 (d, 9H).(363), reddish orange solid. 31 P NMR (121.4 MHz): 6 62.3, 56.8. 1 HNMR (300 MHz): 8 8.20 (m, 211), 7.50 (m, 3H), 7.35 (m, 3H), 6.65 (m, 1H),5.98 (m, 1H), 4.75 (m, 1H), 4.38 (m, 4H), 4.30 (m, 1H), 2.30 (m, 1H), 1.33 (d,9H), 1.14 (d, 9H), -16.94 (dd, 1H, Ji=20.1, J2=6.2). Mass spectrum (FAB):m/e 1042 (P+), 1014, 987, 960, 930, 902, 873, 844, 818, 790, 762, 703(base peak), 638, 629. Anal. calcd. for C38H36FeO8P2Ru3: C, 43.81; H, 3.48.Found: C, 43.99; H, 3.64.(364), reddish orange solid. 31 P NMR (121.4 MHz): 8 60.6, 51.7. 1 HNMR (300 MHz): 8 8.52 (m, 1H), 8.19 (m, 1H), 7.78 (m, 311), 7.40 (m, 2H),6.90 (m, 1H), 6.76 (m, 1H), 6.56 (m, 1H), 4.53 (m, 2H), 4.47 (m, 1H), 4.40(m, 2H), 4.20 (m, 1H), 3.25 (m, 1H), 1.28 (d, 9H), 1.09 (d, 9H), -16.58 (dd,1H, J1=21.3, J2=10.8). Mass spectrum (FAB): m/e 1042 (P+), 1014, 987, 960,930, 902, 873, 844, 818, 790, 762, 703 (base peak), 638, 629.(365), orange solid. 31 P NMR (121.4 MHz): 8 90.1, 40.4. 1 H NMR (300MHz): 8 8.21 (m, 1H), 8.10 (m, 2H), 7.72 (m, 2H), 7.41 (m, 3H), 4.86 (m, 1H),4.70 (m, 1I1), 4.57 (m, 1H), 4.45 (m, 1H), 4.40 (m, 1H), 4.28 (m, 1H), 3.75(m, 1H), 2.65 (m, 1H), 1.23 (d, 9H), 0.88 (d, 9H), -16.07 (dd, 1H, J1=J2=10.5).Mass spectrum (FAB): m/e 1042 (P+), 1014, 987 (base peak), 960, 930,902, 874, 846, 818, 790, 762, 704, 630. Anal. calcd. for C38H36FeO8P2Ru3: C,43.81; H, 3.48. Found: C, 44.13; H, 3.59.193(366), orange solid. 31P NMR (121.4 MHz): 6 80.6, 41.1. 1 H NMR (300MHz): 6 8.18 (m, 2H), 8.02 (m, 1H), 7.42 (m, 3H), 7.23 (m, 2H), 6.92 (m, 1H),4.51 (m, 1H), 4.40 (m, 1H), 4.24 (m, 1H), 4.20 (m, 1H), 4.12 (m, 1H), 3.93(m, 1H), 3.52 (m, 1H), 3.02 (m, 1H), 1.42 (d, 9H), 1.16 (d, 9H), -12.76 (dd,1H, J1=9.0, J2=5.4). Mass spectrum (FAB): m/e 1070 (Pt), 1042 (base peak),1014, 986, 960, 930, 902, 874, 846, 818, 790, 762, 704, 630.(367), reddish orange solid. 31p NMR (121.4 MHz): 8 35.0, 22.8. 1 11NMR (300 MHz): 8 8.13 (m, 3H), 7.64 (m, 111), 7.50 (m, 2H), 7.11 (m, 111),6.88 (m, 1H), 6.50 (m, 1H), 5.48 (m, 2H), 5.11 (m, 1H), 4.75 (m, 1H), 4.66(m, 1H), 3.38 (m, 2H), 1.15 (d, 9H), 1.03 (d, 9H). Mass spectrum (FAB): m/e1095 (Pt), 1072, 1042, 1013, 986, 956 (base peak), 928, 900, 872, 644.3.6.10 Pyrolysis of Ru3(C0)10[Fe(P iPT2)2]Complex Ru3(C0)10[Fe(P iPr2)2] (200 mg, 0.20 mmol) in cyclohexane(100 mL) was refluxed for 15 h. Decomposition was detected after 2 h byTLC and the starting material had completely disappeared after 15 h. Thesolvent was removed in vacuo and the residue was chromatographed on asilica column with 3/1 petroleum ether/CH2C12 as eluent. Two major bandswere eluted, and subsequently a minor one was eluted with CH2C12. Thefirst major band was subsequently resolved into two bands containingcomplexes (368) and (369) on a silica column by using 3/1 petroleumether/ diethyl ether as eluent. The second major band contained complex(370), and the minor band contained complex (371). The approximateyields were as follows: (368), 25%; (369), 15%; (370), 20%; (371), 1%.Crystals of (368) and (371) were obtained from 1/1 hexane/CH2Cl2solutions.194(368), red orange solid. 31p NMR (121.4 MHz): 6 269.4, 67.5. 1 1-1 NMR(300 MHz): 8 5.22-5.14 (m, 1H), 5.00-4.88 (m, 1+2H), 4.60-4.52 (m, 1H),4.45-4.22 (m, 2+1H), 2.35-2.20 (m, 1H), 2.20-2.05 (m, 1H), 1.5-1.2 (m,1211), -18.50 (ddd, 1H, J1=33.3, J2=15.6, J3=2.0), -19.23 (ddd, 1H, J1=21.3,J2=9.0, J3=2.0). Mass spectrum (FAB): m/e 861 (P+), 835, 807, 779, 749(base peak), 721, 706, 693, 678, 665, 650, 622, 604, 591, 565, 550. Anal.calcd. for C24H24FeO8P2Ru3: C, 33.46; H, 2.81. Found: C, 33.20; H, 2.75.(369), orange solid. 31P NMR (121.4 MHz): 6 177.4, 73.7. 1 H NMR (300MHz): 8 4.80 (m, 1H), 4.58 (m, 2H), 4.32 (m, 1H), 4.01 (m, 211), 3.94 (m, 1H),3.85 (m, 1H), 2.85 (m, 1H), 2.58 (m, 2H), 1.8-1.2 (very complex m, 17H), -14.95 (ddd, 1H, J1=32.4, J2=19.2, J3=1.8), -15.45 (ddd, 1H, J1=16.4, J2=9.5,J3=1.8). Mass spectrum (FAB): m/e 903 (P+), 849 (base peak), 821, 793,765, 749, 737, 721, 709, 693, 663, 650, 619, 590, 550. Anal. calcd. forC27H3OFeO8P2Ru3: C, 35.89; H, 3.35. Found: C, 36.04; H, 3.45.(370), orange solid. 31 P NMR (121.4 MHz): 6 429.3, 53.7. 1 H NMR (300MHz): 8 5.25 (m, 1H), 5.20 (m, 1H), 4.90 (m, 2H), 3.83 (m, 1H), 3.50 (m, 1H),3.37 (m, 1H), 3.22 (m, 1H), 2.95 (m, 1H), 2.6-2.4 (m, 2H), 1.7-1.6 (m, 6H),1.10-0.85 (m, 12H), -21.02 (dd, 1H, Ji=22.8, J2=9.0). Mass spectrum (FAB):m/e 849 (P+-00), 821 (base peak), 793, 765, 737. Anal. calcd. forC26H3oFe07P2Ru3: C, 35.67; H, 3.45. Found: C, 35.78; H, 3.54.(371), orange solid. 31 P NMR (81.0 MHz): 8 20.9. 1 H NMR (300 MHz): 65.00-4.95 (m, 2H), 4.5-4.4 (m, 6H), 2.4-2.1 (m, 4H), 1.4-1.0 (m, 24H). Massspectrum (FAB): m/e 997 (Pt), 943, 915, 887, 859 (base peak), 815. Anal.calcd. for C3OH37CIFeO9P2Ru3: C, 36.10; H, 3.74; Cl, 3.55. Found: C, 35.89; H,3.62; H, 3.20.1953.6.11 Pyrolysis of Ru3(CO)12 with P(1 -C10117)3A solution of Ru3(CO)12 (130 mg, 0.20 mmol) and P(1-C10H7)3 (80mg, 0.20 mmol) in cyclohexane (30 mL) was refluxed for 24 h. TLC and 31 PNMR spectroscopy revealed the presence of two major products and threeminor ones. The solvent was removed in vacuo and the residue waschromatographed on silica with 4/1 petroleum ether/CH2C12 as eluent. Thefirst band contained unreacted Ru3(CO)12 (5%). The second band containedcomplex (372) (50%). The third band contained complex (373) (15%). Thefourth band contained a small amount of a mixture of (373) and anothercompound. The fifth band contained traces of a complex identified only bymass spectrometry. A complex showing a 31 P NMR resonance at 40.6 and ahydride at -17.89 ppm (s) was not found.(372), yellow solid. 31 P NMR (81.0 MHz): 6 68.7. 1 H NMR (400 MHz): 69.05 (m, 1H), 8.27-8.15 (m, 2H), 8.10 (d, 2H), 8.04 (m, 1H), 7.92-7.78 (m,4H), 7.73 (m, 1H), 7.46-7.34 (m, 4H), 7.30 (m, 1H), 7.22 (m, 1H), 7.16 (m,1H), 7.07 (m, 1H), -15.78 (d, 1H, J=5.2), -19.88 (d, 1H, J=37.4). Massspectrum (FAB): m/e 941 (P+), 913, 885, 857, 829, 800, 771, 743, 728, 714(base peak), 585. Anal. calcd. for C38H21O8PRu3: C, 48.57; H, 2.25. Found: C,48.66; H, 2.32.(373), pink brown solid. 31 P NMR (81.0 MHz): 6 71.9. 1 H NMR (200MHz): 6 8.30-6.85 (complex m). Mass spectrum (FAB): m/e 1067 (P+, basepeak), 1038, 1012, 984, 956, 928, 914, 900, 883, 872, 855, 844, 827, 814,800, 771, 744, 714, 645, 615, 596, 568, 540, 527, 512.The fourth band, brown solid. 3 1 P NMR (81.0 MHz): 6 92.8; 71.9 (373).1 11 NMR (200 MHz): 6 9.0-8.6 (m), 8.3-6.8 (complex m). TLC: 2 spots.The fifth band, brown solid. Mass spectrum (FAB): m/e 1456 (P+),1961427, 1399, 1371 (base peak), 1343, 1310, 1290, 1264, 1240, 1213, 1183,1155 , 1013.3.6.12 Pyrolysis of Ru3(CO)12 with As(1-C10117)3Triruthenium dodecacarbonyl (128 mg, 0.20 mmol) and As(1-C1oH7)3(95 mg, 0.21 mmol) in cyclohexane (30 mL) was refluxed for 10 h. 1 H NMRspectroscopy revealed the presence of two hydrides with equal intensity.The solvent was removed in vacuo, and the residue was chromatographedon silica with 4/1 petroleum ether/CH2C12 as eluent. The first band gaveRu3(CO)12 (5%). The second orange, fourth reddish orange, and fifth brownbands have not been characterized. The third major band containedcomplex (374) (70%).(374), yellow solid. 1 H NMR (200 MHz): 8 8.46 (m, 2H), 8.08 (d, 1H),8.02 (d, 111), 7.91 (m, 2H), 7.86-7.72 (m, 411), 7.58 (m, 1H), 7.44-7.14 (m,8H), -15.93 (s, 1H), -20.35 (s, 111). Mass spectrum (FAB): m/e 984 (Pt, basepeak), 956, 928, 900, 871, 843, 815, 787, 759, 630. Anal. calcd. forC38H2lAsOgRu3: C, 46.40; H, 2.15. Found: C, 46.57; H, 2.09.3.6.13 Pyrolysis of Ru3(CO)12 with SFcPhA solution of Ru3(C0)12 (250 mg, 0.39 mmol) and SFcPh (100 mg,0.34 mmol) in toluene (50 mL) was refluxed for 11 h. The solution changedcolour from orange to dark red in 15 min and to dark brown in 50 min.TLC revealed the presence of three major products. The solvent wasremoved in vacuo and the residue was chromatographed on silica with 3/1petroleum ether/CH2C12 as eluent. The first band (25%) contained amixture of two complexes. The second yellow band contained (375) (55%).197The third band (10%) contained a complex characterized only by 1 H NMRspectroscopy.The first band, yellow solid. 1 H NMR (400 MHz): 8 7.48 (bm), 7.25(m), 7.16 (m), 7.04 (m), 4.77 (bm), 4.41 (bm), 4.32 (m), 4.27 (s), 4.17 (bm).TLC: 2 spots.(375), yellow solid. 1 H NMR (200 MHz): 8 6.57 (m, 1H, Ph), 6.05 (m,2H, Ph), 5.28 (m, 1H, Ph), 4.65 (m, 1H, Ph), 4.41 (m, 1H), 4.24 (m, 1H), 4.21(s, 5H), 4.14 (m, 1H), 4.07 (m, 1H). Mass spectrum (FAB): m/e 823 (P+),794, 767, 739, 710, 683, 654, 626, 597 (broad, base peak), 532, 521. Anal.calcd. for C241114FeOgRu3S: C, 35.09; H, 1.72. Found: C, 35.18; H, 1.88.The third band, orange solid. 1H NMR (200 MHz): 8 7.25-7.10 (m),7.08-7.00 (m), 6.88-6.78 (m), 4.38 (m), 4.33 (m), 4.25 (s), 4.17-4.07 (m),3.90-3.80 (m), 3.80-3.50 (very broad m), 3.12 (m), 2.93 (m).3.6.14 Pyrolysis of Ru3(CO)12 with SPh2A solution of Ru3(CO)12 (192 mg, 0.30 mmol) and SPh2 (1 mL, excess)in toluene (25 mL) was refluxed for 15 h. TLC revealed the formation ofone major and two minor products. The solvent was removed in vacuo, andthe residue was chromatographed on alumina with 3/1 petroleumether/CH2C12 as eluent. The first orange band (15%) has not beencharacterized. The second major band contained complex (376) which wasobtained as a yellow solid in 70% yield. 1 H NMR (300 MHz): 8 7.41 (m, 2H),7.23-7.08 (m, 3H), 6.58 (tm, 1H), 6.00 (m, 2H), 5.34 (tm, 1H), 4.70 (dm, 1H).Mass spectrum (FAB): m/e 715 (P+), 687, 659, 630 (base peak), 601, 574,548, 519, 490. Anal. calcd. for C201-11008Ru3S: C, 33.66; H, 1.41. Found: C,33.33; H, 1.52.198PART THREE: RESULTS AND DISCUSSIONChapter 4 Pyrolysis of Triosmium ComplexesContaining Ferrocenyl Ligands4.1 Pyrolysis of 0s3(C0)11(PFcPh2)The pyrolysis of 0s3(C0)11(PFcPh2) has been examined under severalreaction conditions. In all, five complexes, (339) to (343), have beencharacterized, and their characterization is described below.Pyrolysis of 0s3(C0)11(PFcPh2) in octane for 3 h affords one majorand at least three minor products as judged by TLC, 1 H, and 31 P NMRspectroscopy. The hydride resonances in the 1 H NMR spectrum are due tominor products including complex 0s3(C0)8(H)2f(C5H3PPh2) Fe(C5H4)] (245)1^ 17. 5^7.1 6.5^6^5.5^5.1^4.5^4.S^3.5PriFigure 4.1 300 MHz 1 H NMR spectrum of complex (239).20008AAC24CalFEICa06^C. or G6`411P^C7C5^A, CIO 0.ek •40• 111C3• • • C9 •083•C13Cil054/ 4irj or■&i.ve a -=-1 •09C2307C25CI;14 C1903CISC16C20OF:C18C17010402which will be described in the next section.Complex (239), the only major product obtained from the reaction,shows a 3 IP NMR resonance at 207.3 ppm suggesting the presence of aphosphinidene moiety. The mass spectrum gives the parent ion at 1114corresponding to the loss of one phenyl and two CO groups from thestarting material. The IH NMR spectrum, Figure 4.1, shows the presence ofa C6H4 moiety and a ferrocenyl group corresponding to a formula such as0s3(C0)9(PFc)(C6H4). The pyrolysis of 0s3(C0)11(PPh2R) (R-Ph, Et, Me) isknown to afford asymmetrically bound benzyne derivatives (121) [131-1331, and (239) is probably closely related. This was confirmed by using X-ray crystallography. An ORTEP diagram of (239) with 50.0% probabilitythermal ellipsoids is shown in Figure 4.2.Figure 4.2 ORTEP diagram of complex (239).201Crystal data: fw-1114.79, red, irregular, triclinic system, space groupP1 (#2), a-10.858(3), b-13.960(3), c-10.383(3) A, a-95.54(3), 0-110.98(2),'y-106.34(2)°, V-1375.5(7) A 3 , Z-2. Dcalc-2 .691 g/cm3, R-0.035, Rw-0.040.As expected, the structure of (239) is very similar to 0s(C0)9(PMe)(C6H4) (121b) [133] and 0s3(C0)9(PEt)(C6H4) (121a) [131]. It consists of anopen 0s3 metal framework capped on one face by a benzyne moiety and onthe other by a phosphinidene moiety. An alternative description wouldhave the aryne moiety bonded to the 0s3P butterfly assembly (the anglebetween the Os(1)0s(2)P(1) and Os(2)0s(3)P(1) planes is 53.77 0 ). The C6H4ligand is asymmetrically bonded as described previously for (121) withC(1 1) bonded only to Os(1) while C(12) bridges Os(2) and Os(3). The C(1 1)-Os(1) bond at 2.118(7) and C(12)-0s(2) at 2.160(8) A are consistent withtwo a bonds, but the longer C(12)-0s(3) bond at 2.318(7) A indicates aweaker interaction. The C(12) bridged Os(2)-0s(3) bond at 2.780(1) A isshorter than the Os(1)-0s(2) bond at 2.9156(9) A, and the Os(1)-0s(2)-0s(3) angle is 88.54(3) ° . The phosphinidene moiety PFc is also bonded tothe 0s3 framework asymmetrically with the P(1)-0s(2) bond being thelongest at 2.423(2) A, P(1)-0s(1) and P(1)-0s(3) bonds are shorter at2.310(2) and 2.333(2) A respectively.The structure of (239) is better than that of (121a) and (121b) in acrystallographic sense and comparison of some bond lengths in (239) canbe made that are not possible for the other compounds. Those carbonylstrans to the P -Os or a C (C6H4)-Os bonds have appreciably longer Os-Cbonds (0s(1)-.C(18) 1.948(8), Os(1)-C(19) 1.951(8), Os(3)-C(24) 1.959(8) A),Os(1)-C(17) at 1.876(8) and Os(3)-C(25) at 1.885(9) A are somewhatshorter than the rest which average to 1.915 A. In the ferrocenyl moiety,the two Cp rings shows an eclipsed configuration and have a small ring tilt202angle of 2.74°. The benzyne moiety is tilted 65.10° from the 0s3 plane, andthis value is greater than 60.7 and 58.9° reported for (121b) and (121a)respectively, but it is smaller than 72.3° of (122a) which has a PEt3 ligandbonded to Os(3) [133]. Os(1) and Os(2) are out of the C6H4 plane by 0.4246and 0.4370 A respectively. The C(11)-C(12), C(11)-C(16), and C(12)-C(13)bonds (1.43(1), 1.43(1), and 1.40(1) A) are probably slightly lengthened.The AA'BB'X (X= 31 P) pattern for the benzyne moiety observed in the1 H NMR spectrum indicates a fluxionality of the moiety as was noted for(121a) and (121b) [131, 133]. The processes leading to these exchangeshave been discussed previously in Section 1.2.3.2 and one process involvesa symmetrical intermediate in which there are two equivalent a bonds tothe terminal Os atoms [133]. A ferrocyne complex (252) with suchsymmetrical structure has been characterized and is discussed later inSection 4.3.Complex (240) shows a 3 1 13 NMR resonance at 65.4 ppm suggestingthe presence of a phosphido moiety. The mass spectrum gives the parention at 1142 corresponding to the loss of one CO and one phenyl group fromthe parent. The 1 H NMR spectrum shows the presence of a C6H4 moiety anda ferrocenyl group. By analogy with 0s3(C0)9(p.-00)(PMeC6H4) (232)obtained from 0s3(C0)11(PMePh2) [132], a formula such as 0s3(C0 )9(11-C0)(PFcC6H4) is very likely, and a structure similar to (232) is proposedand shown in Figure 4.3.The complex in the fourth band was not obtained in sufficientquantity to be fully characterized. Its mass spectrum gives the parent ionat 1114, the same as that of (239), and possibly it is a ferrocyne complexsuch as 0s3(C0)9(PP11)[(C5H3)Fe(C5H5)[, analogous to 0s3(C0)9(PFc)[(C5H3)Fe(C5H5)1 (252) which will be described in Section 4.3.203Fc^ Os(C0)3COOs(CO)3Figure 4.3 A proposed structure for complex (240).The fifth band contains a complex mixture, and its NMR spectrumshows many interesting hydride resonances including those of (242)described below and (245) which will be described in the next section.Pyrolysis of the same starting material (0s3(C0)11(PFcPh2)) in octanefor 21 h affords a greater number of products, and 31 P NMR spectroscopyrevealed the presence of many complexes containing phosphido/phosphinidene moieties. The third, fifth, and seventh bands all containsuch phosphido/phosphinidene complexes in small quantities. Clearly moreextensive cleavage reactions have occurred. The characterization