Vibrational spectra and structure of crystalline potassium perthiocarbonate–methanol K2CS4, CH3OH

Abstract

The i.r. and Raman spectra of polycrystalline K₂CS₄, CH₃OH and K₂CS₄, CH₃OD addition compounds have been investigated in the 4 000–50 cm^–1 range. Most of the intramolecular fundamentals have been assigned and the spectroscopic and X-ray diffraction data are correlated. The hydrogen bonded CH₃OH molecules are characterized by 3400 and 3240 cm^–1 OH stretching frequencies corresponding to OH ⋯ O and OH ⋯ S interactions, respectively. The valence force field determined for the two nonequivalent CS₄^2– anions gives four different C–S stretching force constants varying from 3.4 to 4.2 mdyn Å^–1 and consistent with the C–S distances; however, no CS double bond is expected from the spectroscopic data.