Spectra and Structure of Silicon-Containing Compounds. XII. Infrared and Raman Spectra of Trimethylvinylsilane and Trimethyl-D 9 -vinylsilane

Abstract

The Raman spectra (0 to 3300 cm⁻¹) of (CH₃)₃Si(CHCH₂) and (CD₃)₃Si(CHCH₂) in the gaseous, liquid and solid states have been recorded. The infrared spectra (20 to 3300 cm⁻¹) of the same two compounds in the gaseous and solid states have also been recorded. A vibrational assignment based upon depolarization ratios, frequency shifts with isotopic substitution, infrared band contours, and group frequencies is proposed. The SiC₃ torsion was observed at 55 and 50 cm⁻¹ for the “light” and “heavy” molecules, respectively, and the barriers to internal rotation were calculated to be 0.73 kcal/mol and 0.64 kcal/mol for the light and heavy compounds, respectively. These results are compared to the corresponding data for similar molecules.