15min:

DONGSHENG HAN, C. M. L. RITTBY AND W. R. M. GRAHAM, Department of Physics, Texas Christian University, Fort Worth, TX 76129.

Fourier transform infrared studies have resulted in the first observation of vibrational spectra of the linear SiCH and non-planar H₂SiCCH radicals produced by trapping the products of the vacuum ultraviolet photolysis of a mixture of SiH₄ silane, and C₂H₂ acetylene, in an Ar matrix at about 10 K. The silicon-carbon stretching mode ₁() of SiCH has been observed at 1010.4 cm^-1. Two vibrational fundamentals of H₂SiC₂H have been identified, the ₃(a'), silicon-carbon stretching mode at 2055.6 cm^-1 and the ₄(a'), hydrogen-silicon bending mode at 926.8 cm^-1. The results of extensive measurements of D and ¹³C isotopic shifts are in good agreement with the predictions of coupled cluster ab initio calculations performed at the CCSD(T)/6-31G** level and confirm the proposed identifications.

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^aResearch supported by the Welch Foundation