Silylidyne, HSiMoH3 and HSiWH3, and Silyl Metal Hydride, SiH3CrH, Products in Silane Reactions

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• 作者：Xuefeng Wang ; Lester Andrews
• 刊名：Journal of the American Chemical Society
• 出版年：2008
• 出版时间：May 28, 2008
• 年：2008
• 卷：130
• 期：21
• 页码：6766 - 6773
• 全文大小：738K
• 年卷期：v.130,no.21(May 28, 2008)
• ISSN：1520-5126

文摘

Laser-ablated group 6 metal atoms react with silane to form inserted SiH₃−MH hydride intermediates, which are identified from M−H and Si−H stretching modes. Following two successive α-H-transfers, the HSirc="http://pubs.acs.org/images/entities/tbd1.gif">MH₃ (M = Mo, W) silylidyne molecules are produced. These silicon−metal triple-bonded species are identified as major products from the strong M−H stretching modes through deuterium substitution and comparison with frequencies and intensities from density functional calculations and from the analogous methylidynes. The silylidynes have calculated C_3v structures and longer Si−H bonds than silane, but the C_3v methylidyne analogues have shorter C−H bonds than methane. The Sirc="http://pubs.acs.org/images/entities/tbd1.gif">Mo and Sirc="http://pubs.acs.org/images/entities/tbd1.gif">W bonds are polarized differently and have slightly lower effective bond orders than their carbon analogues. In addition, calculations for the group 6 silylidene molecules reveal C_s structures with no evidence of agostic distortion, in contrast to the corresponding methylidene molecules.