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Wu Yuen Sze. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1999. / Includes bibliographical references (leaves 98-107). / Abstracts in English and Chinese. / Table of contents --- p.i / Acknowledgements --- p.iv / Abstract --- p.v / List of compounds --- p.vi / Abbreviations --- p.x / Chapter Chapter 1 --- Synthesis and Structures of Low-valent Group14 Organometallic Compounds --- p.1 / Chapter 1.1 --- General apects of low-valent group 14 compounds --- p.1 / Chapter 1.2 --- Structures of germylenes and stannylenes --- p.3 / Chapter 1.3 --- Tetravalent group 14 Metal amides --- p.7 / Chapter 1.4 --- Objectives --- p.11 / Chapter 1.5 --- Results and Discussion --- p.12 / Chapter 1.5.1 --- Synthesis of germanium(II) compound [Ge{C(C5H4N- 2)C(Ph)N(SiMe3)2}{N(SiMe3)C(Ph)C(SiMe3)(C5H4N- 2)}] (29) --- p.12 / Chapter 1.5.2 --- Synthesis of tin(II) amide [Sn{N(SiMe3)C(Ph)C- (SiMe3)(C5H4N-2)}2] (30) --- p.14 / Chapter 1.5.3 --- Synthesis of tin(IV)(amide)dichloride [Sn{N(SiMe3)C- (Ph)C(SiMe3)(C5H4N-2)}2Cl2] (31) --- p.15 / Chapter 1.5.4 --- Spectroscopic Properties of Compounds 29-31 --- p.16 / Chapter 1.5.5 --- Molecular Structure of [Ge{C(C5H4N-2)C(Ph)N(Si- Me3)2}{N(SiMe3)C(Ph)C(SiMe3)C(C5H4N-2)}] (29) --- p.21 / Chapter 1.5.6 --- Molecular structure of [Sn{N(SiMe3)C(Ph)C(SiMe3)- (C5H4N-2)}2] (30) --- p.25 / Chapter 1.5.7 --- Molecular structure of [Sn{N(SiMe3)C(Ph)C(SiMe3)- (C5H4N-2)}2C12] (31) --- p.28 / Chapter Chapter 2 --- Synthesis and Structure of Group 14 Metal- Chalcogenones --- p.32 / Chapter 2.1 --- Multiple bond between group 14 metals and chalcogens --- p.32 / Chapter 2.2 --- Results and Discussion --- p.39 / Chapter 2.2.1 --- "Synthesis of germane- and stannane-chalcogenones [(RI)(R1.)Ge=E], [E = S 59, Se 60], [(R1)2Sn=S] (61)， [(R1)(R1.)Sn=Se] (62)" --- p.39 / Chapter 2.2.2 --- Spectroscopic properties of compounds 59-62 --- p.41 / Chapter 2.2.3 --- Molecular structure of [{N(SiMe3)C(Ph)C(SiMe3)- (C5H4N-2)}2Sn=S] (61) --- p.46 / Chapter 2.2.4 --- "Molecular structure of [{N(SiMe3)2C(Ph)C(C5H4N-2)}- {N(SiMe3)C(Ph)C(SiMe3)(C5H4N-2)}M=E] [M = Ge, E =S 59，Se 60; M = Sn,E = Se 62]" --- p.52 / Chapter Chapter 3 --- Reactivity of Low-valent Group 14 Organometallics Compounds --- p.59 / Chapter 3.1 --- Introduction --- p.59 / Chapter 3.1.1 --- Lewis-base behavior --- p.60 / Chapter 3.1.2 --- Lewis-acid behavior --- p.63 / Chapter 3.1.3 --- Oxidative-addition (or insertion) reactions --- p.65 / Chapter 3.2 --- Results and Discussion --- p.69 / Chapter 3.2.1 --- Lewis acid base behavior of [Sn(R2)2] (27) --- p.69 / Chapter 3.2.1.1 --- "Reaction of [Sn(R2)2] (27) with group 11 metal derivatives (M = Ag, X = Cl 91,I 92,SCN 93，CN94; M = Cu, X = Cl 95，I 96)-Synthesis of [(R2)2Sn→(μ- MX)]2" --- p.69 / Chapter 3.2.2 --- Oxidative-addition (or insertion) reaction of tin(II) compounds --- p.73 / Chapter 3.2.2.1 --- Reaction of AgNCO with [Sn(R2)2] (27) 一 Synthesis of [(R2)2Sn(NCO)2](97) --- p.73 / Chapter 3 .2.3 --- Spectroscopic properties of compounds 91-97 --- p.74 / Chapter 3.2.4 --- Molecular structure of [{CH(SiMe3)C9H6N-8}2Sn→(μ- AgCl)]2 (91) --- p.80 / Chapter 3.2.5 --- Molecular structure of [{CH(SiMe3)C9H6N-8}2Sn- (NCO)2] (97) --- p.85 / Appendix I / Chapter A. --- Experimental procedures for chapter 1 --- p.87 / Chapter B. --- Experimental procedures for chapter 2 --- p.90 / Chapter C. --- Experimental procedures for chapter 3 --- p.93 / Appendix II / Chapter A. --- References for chapter 1 --- p.98 / Chapter B. --- References for chapter 2 --- p.102 / Chapter C. --- References for chapter 3 --- p.104 / Appendix III / Chapter A. --- General procedures --- p.106 / Chapter B. --- Physical and analytical measurements --- p.106 / Appendix IV / Table A.l. Selected crystallographic data for compounds 29，30，31 --- p.109 / Table A.l. Selected crystallographic data for compounds 59，60，61 --- p.110 / "Table A.l. Selected crystallographic data for compounds 62, 91，97" --- p.111

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemistry, 1982. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND SCIENCE / Vita. / Includes bibliographical references. / by Scott M. Rocklage. / Ph.D.

The reaction of the model compound hexachlorocyclotriphosphazene (N₃P₃Cl₆) with various organometallic reagents have been studied in some detail. These reactions are quite complex yielding substitution products as well as degradation products. The reaction of alkyl Grignard reagents, in the presence of a copper complex ((n-Bu₃PCuI)₄), have been studied and produce good yields of mono- and di-alkylated chlorocyclotriphosphazenes. This method is limited in that higher substitution products can not be obtained. The reaction of trimethylaluminum (TMA) with (N₃P₃Cl₆) was examined and found to yield the fully substituted hexamethylcyclotriphosphazene (N₃P₃(CH₃)₆) in modest yield (40 %). The study of this reaction, with respect to time allowed for the determination of the substitution pathway and the preparation of two new methylated chlorocyclotriphosphazenes. It was then possible to prepare a nearly complete set of methylated chlorocyclotriphosphazenes (N₃P₃(CH₃)_nCl_6-n) using this method and the Grignard route. The reactions of other alkylaluminum reagents were also examined and are discussed. The effects of the complexation of TMA with the homologous series was next examined using ¹H, and ³¹P NMR. The results for these investigations indicate that the overall electron donating ablity of the phosphazene ring increased with increasing methyl substitution. Variable temperature NMR studies allowed for the determination of the sites of complexation and their relative strengths with respect to the number of methyl groups on the phosphazene ring. / Ph. D. / incomplete_metadata