Vibrational and conformational study of FSO2NCO: FT-IR, preresonance Raman effect, force field and theoretical calculations

Abstract

Abstract Starting with ClSO 2 NCO and SbF 3 , fluorosulphuryl isocyanate, FSO 2 NCO, was prepared. FT-IR data for the vapour and Raman spectra for the liquid were obtained. The observed features and the pre-resonance Raman data are consistent with the existence of only one conformer possessing C 1 symmetry both in the vapour and liquid phase. For all but the torsional mode of this rotamer, experimental wavenumbers are reported. Symmetry force constants were calculated using a torsional frequency taken from ClSO 2 NCO. The experimental studies were augmented by ab initio calculations at various levels of sophistication (HF/3-21G*, HF/6-31G*, MP2/6-31G*). The predicted conformational properties for FSO 2 NCO are in good agreement with the experimental data.