Infrared Spectrum of Methylsilylacetylene

Abstract

The compound methylsilylacetylene has been prepared for the first time and its vibrational spectrum has been obtained and assigned. All but two of the fundamentals have been identified. The rotational Q branches of the perpendicular bands have been resolved for the three group modes of SiH₃, and a comparison of the Coriolis coupling constants with those of other silyl‐containing molecules indicates a low or vanishing barrier to internal rotation. The relative intensities of the Q branches further supports this observation.