THE FAR-INFRARED TORSIONAL SPECTRUM OF METHYL SILANE

Author Institution: Department of Physics, University of British; Department of Chemistry, Texas A\&M UniversityThe torsional transitions in symmetric tops with internal rotation are known to be weak and are allowed only through vibration-torsion-rotation interactions. The torsional spectrum is here reported of methyl silane taken with Fourier transform spectroscopy in the region $150-380 cm^{-1}$ at a resolution of $0.15 cm^{-1}$. Densities ranged from 0.36 to 0.96 amagats with a path length of 12.4m; the sample was at room temperature. Several torsion-rotation bands from torsional levels with v = 0, 1, and 2 have been observed. Work is underway to analyse the present data along with the microwave frequencies and molecular beam splittings available to obtain the torsion-rotation constants and the parameters characterizing the transition dipole operator. Preliminary results will be reported. $^{*} $Current Address: Canada Centre for Remote Sensing, Ottawa K1A 0Y7, Canada. $\dag $On leave (1982-83) at the Herzberg Institute of Astrophysics. National Research Council, Ottawa K1A OR6, Canada