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

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 C3v, and normal coordinate calculations are reported for all three ions. Comparisons are made among the spectra of these ions and those of related XSO3− species. Because of mechanical coupling and electronic effects it is not possible to estimate the effective electronegativity of the CF3 group on the basis of the frequencies of vibrations assigned to the SO3 group in CF3SO3−.