Vibrational Spectrum of Methaneselenol

The infrared spectra of CH3SeH, CH3SeD, CD3SeH, and CD3SeD have been investigated from 250 to 4000 cm−1 in both the vapor and the solid states. The Raman spectra of all four compounds in the liquid phase have been recorded. A complete vibrational assignment and normal-coordinate calculation have been carried out. In CD3SeH a large repulsion exists between the methyl wagging mode and the Se–H bending vibration. The far-infrared spectrum of CH3SeH has a broad band centered at about 145±40 cm−1, which is assigned to the torsional vibration. A height of 320±40 cm−1 for the barrier to internal rotation is calculated from the torsional frequency.