15min:

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

Fourier transform infrared studies of small hydrogen bearing silicon-carbon clusters trapped in solid Ar have resulted in the identification of new species. Among those so far investigated is the linear SiCCH radical produced from the products of the vacuum ultraviolet photolysis of a mixture of SiH₄ silane, and C₂H₂ acetylene. Two fundamentals of SiCCH have been abserved, the ₂(), carbon-carbon stretching mode at 1989.8 cm^-1 and the ₃(), silicon-carbon stretching mode at 636.0 cm^-1. Also investigated is SiCH produced by the photolysis of SiH₄ and CH₄ methane. The identification of vibrational modes and determination of structures for these species is based on comparison of measured frequencies, relative intensities, and the results of extensive measurements of D and ¹³C isotopic shifts with the results of ab initio calculations performed in conjunction with this work .