title: Silylidyne, HSi[triple bond]MoH3 and HSi[triple bond]WH3, and silyl metal hydride, SiH3-CrH, products in silane reactions.
abstract: Laser-ablated group 6 metal atoms react with silane to form inserted SiH 3-MH hydride intermediates, which are identified from M-H and Si-H stretching modes. Following two successive alpha-H-transfers, the HSiMH 3 (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 3 v structures and longer Si-H bonds than silane, but the C 3 v methylidyne analogues have shorter C-H bonds than methane. The SiMo and SiW 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.
authors.affiliation: Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904-4319, USA.
authors.forename: Xuefeng
authors.initials: X
authors.lastname: Wang
authors.forename: Lester
authors.initials: L
authors.lastname: Andrews