Bis (trifluoromethyl) sulfone, CF3SO2CF3: Synthesis, vibrational and conformational properties

Abstract

Bis (trifluoromethyl) sulfone, CF3SO2CF3, was obtained as a byproduct in the synthesis of CF3SO2SCF3. The compound was characterized by infrared and Raman spectroscopy as well quantum chemical calculations. Quantum mechanical calculations indicate the possible existence of two conformers symmetrically equivalent with C2 symmetry. The preference for the staggered form was studied using the total energy scheme and the natural bond orbital (NBO) partition scheme. Additionally, the total potential energy was deconvoluted using a six-fold decomposition in terms of a Fourier-tipe expansion, showing that the hyperconjugative effect was dominant in stabilizing the staggered conformer. Infrared and Raman spectra of CF3SO2CF3 were obtained. Harmonic vibrational wavenumbers and a scaled force field were calculated, leading to a final root mean-square deviation of 7,8 cm-1 when comparing experimental and calculated wavenumbers.