无机化学学报

新型过渡金属硅基化合物的合成、表征及反应性

A NEW FAMILY OF TRANSITION METAL SILYL COMPLEXES, THEIR SYNTHESES, CHARACTERIZATION AND REACTIVITIES

作者	单位
陈天牛	Department of Chemistry, University of Tennessee, Knoxville, TN 37996-1600， U.S.A
薛子陵	Department of Chemistry, University of Tennessee, Knoxville, TN 37996-1600， U.S.A

摘要: 在这篇综述中，我们将简要地介绍我们在新一类的金属硅基化合物(RCH₂)₃MSiR′₃(M=Ti, Zr), (RCH₂)₂Ta(=CHR)SiR′₃和(RCH₂)₂W(≡CR)SiR′₃方面的工作，并讨论亚烷基、氨基化合物与硅烷之间的反应。这些研究具有以下的两重意义：(1)探索从分子前体形成金属硅化物的机理。(2)研究新一类金属硅基化合物的合成、结构及它们与硅烷的反应性。我们还通过对烷基和硅基配体在形成亚烷基配合物时不同的反应机理的研究来比较元素碳和硅之间的反应性。在这方面的研究中，我们发现“(RCH₂)₂Ta(=CHR)Cl”为在(RCH₂)₃TaCl₂和Li(THF)₃SiR₃的反应中形成硅基亚烷基化合物(RCH₂)₂Ta(=CHR)SiR₃(R=SiMe₃)的中间体而Ta(CH₂R)₅(R=CMe₃, SiMe₃)则是从(RCH₂)₃TaCl₂生成烷基亚烷基化合物(RCH₂)₃Ta=CHR的中间体。除此之外，金属氨基(M-NR₂)化合物与硅烷之间的反应被证明可以可逆地生成氨基氢化物和氨基硅烷。我们将一并讨论这一结果对于阐明金属硅化物和M-Si-N三元体系物质的形成机理的意义。

关键词: 硅基化合物前期过渡金属烷基、亚烷基、次烷基和氨基化合物氢化物

基金项目:

Abstract: In this review, our studies of a new family of silyl complexes (RCH₂)₃MSiR′₃(M=Ti, Zr), (RCH₂)₂Ta(=CHR)SiR′₃ and (RCH₂)₂W(≡CR)SiR′₃, which are free of cyclopentadienyl (C_p) or other supporting anionic π-ligands, and the reactions of alkylidene and amide complexes with silanes are summarized. We have conducted these studies with a two-fold interest: (1) mechanistic pathways in the formation of metal silicides (MSi_n) from molecular precursors; (2) fundamental chemistry of these reactions with silanes and the new silyl complexes-their syntheses, structures and reactivities. We have also explored the differences between carbon and silicon as well as alkyl and silyl ligands in the mechanistic pathways of the formation of silyl and alkyl alkylidene complexes. The formation of a silyl alkylidene complex (RCH₂)₂Ta(=CHR)SiR₃(R=SiMe₃) from (RCH₂)₃TaCl₂ and Li(THF)₃SiR₃ was found to go through “(RCH₂)₂Ta(=CHR)Cl” as an intermediate. In contrast, Ta(CH₂R)₅(R=CMe₃, SiMe₃) were found to be the intermediates in the formation of archetypical alkyl alkylidene complexes (RCH₂)₃Ta=CHR from (RCH₂)₃TaCl₂. In addition, the reactions of amide (M-NR₂) complexes and silanes were found to reversibly yield amide hydride complexes and aminosilanes. The significance of these results to the elucidation of mechanistic pathways in the formation of metal silicides and M-Si-N ternary meterials will be discussed.

Keywords: silyl complexes early transition metals hydride compounds alkyl, alkylidene, alkylidyne and amide complexes

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陈天牛,薛子陵.新型过渡金属硅基化合物的合成、表征及反应性[J].无机化学学报,1999,15(4):413-422.

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