Infrared and Raman spectra and theoretical study of methyl trifluoromethylsulfone, CF3SO2CH3

The infrared and Raman spectra were obtained for liquid CF3SO2CH3, as well as the infrared spectrum of the gaseous substance. The molecular geometry w as optimized by means of the Hartree-Fock (HF), second order electron corre lation (MP2) and density functional theory (DFT) procedures of quantum chem istry, resulting in a structure with C-s symmetry. The wavenumbers correspo nding to the normal modes of Vibration were calculated using the DFT (B3LYP /6-31G**) approximation and their agreement with the measured values improv ed after scaling of the associated force field. An assignment of bands is p roposed on the basis of such calculations and the comparison with related m olecules. (C) 2000 Elsevier Science B.V. All rights reserved.