Raman and infrared spectra and normal coordinates of the trifluoromethanesulfonate and trichloromethanesulfonate anions

Abstract

The Raman spectra of aqueous solutions of sodium and barium trifluoromethanesulfonate and sodium trichloromethanesulfonate including qualitative polarization measurements together with the infrared spectra of mulls of these salts have been recorded. Spectra also were obtained for the methanesulfonate ion which has been studied previously. Qualitative vibrational assignments have been made assuming an effective point group C 3 v , and normal coordinate calculations are reported for all three ions. Comparisons are made among the spectra of these ions and those of related XSO 3 − species. Because of mechanical coupling and electronic effects it is not possible to estimate the effective electronegativity of the CF 3 group on the basis of the frequencies of vibrations assigned to the SO 3 group in CF 3SO 3 −.