Vibrational Spectra and Structure of Organophosphorus Compounds. VI. Infrared and Raman Spectra of CH3OPSF2 and CD3OPSF2

Abstract

The infrared spectra of both CH₃OPSF₂ and CD₃OPSF₂ in the vapor phase have been recorded from 4000 to 33 cm⁻¹. Carbon disulfide solution spectra were also investigated to 200 cm⁻¹. The Raman spectra of the liquids and solids have been recorded and depolarization values measured. At least two isomeric configurations are indicated from the low‐temperature Raman spectra, and from the lack of the variation of band intensity, it is concluded they have nearly equal energy. Only one torsional vibration was observed at 192 cm⁻¹, and it is concluded that it is composed of the CH₃ and P–O–C torsional vibrations and possibly mixed with other low‐frequency skeletal modes. The doublet due to the P=S stretching vibration has a separation of only 31 cm⁻¹, whereas 100–150 cm⁻¹ has been proposed as the separation for this normal mode in this type of compound. The other fundamental vibrations are assigned based on band positions, depolarization values, and isotopic shifts. The assignments are also compared to those previously given for the CH₃OPCl₂ and CH₃OPSCl₂ molecules.