Pentafluoroethyliminosulfur difluoride, CF 3CF 2N [dbnd]SF 2: Vibrational spectra and quantum chemical calculations

Abstract

The vibrational spectra of pentafluoroethyliminosulfur difluoride, CF 3CF 2N SF 2, were recorded in the gas phase with IR spectroscopy and in the liquid state with Raman spectroscopy. Quantum chemical calculations at the B3LYP (6-311+G(d) and 6-311+G(2df) basis sets) and MP2 levels of theory (6-31+G(d) and 6-311G(d) basis sets) were performed. According to all calculations the lowest energy conformer possesses C 1 symmetry with syn orientation of the SF 2 group relative to the C N bond and near- trans orientation of the CF 3 group relative to the N S bond ( syn- trans). Calculations predict the hypothetical presence of a second stable conformer with anti-orientation of the SF 2 group ( anti- trans) which, however, possesses considerably higher energy and is therefore not observed in the analysis of the experimental spectra. The vibrational spectra were assigned for a single conformer in agreement with these calculations.