Gas-phase structure of trifluoromethyl trifluoromethanesulfonate, CF3SO2OCF3: conformational and vibrational properties

M. E. TUTTOLOMONDO; E ARGAÑARAZ, P; EDUARDO LELIO VARETTI; A HAYES, S; D. W. H. RANKIN; E ROBERTSON, H; BEN ALTABEF, A

Estambul

Congreso; XXVIII European Congress on Molecular Spectroscopy; 2006

   CF3SO2OCF3 was synthesized by reaction of CF3SO2OH with (CF3SO2)2 according to the method reported by Hassani y col.. The gas phase structure was determined using electron diffraction techniques, supported by HF, MP2 and DFT (B3LYP) calculations for the  structure. The experimental and theoretical results showed agreement in the description of  CF3SO2OCF3 as a single conformer with gauche orientation of the two CF3 groups  and with a dihedral angle CSOC of 128.6(16)o by GED compared to 110.8o by theory. Such a gauche conformation seems to be a common structural characteristic of covalent sulfonates .    Infrared and Raman spectra were obtained for the substance, in which bands assignable to  27 out of the expected 30 normal modes of vibration were observed. These experimental data along with the theoretically calculated force constants are used to define a Scaled Quantum Mechanical  force field for the target molecule, which allowed reproducing the measured frequencies with a final root mean square deviation of 6.0 cm-1 after a reliable assignment of the vibrational spectrum.