VIBRATIONAL AND CONFORMATIONAL STUDY OF FSO2NCO-FT-IR, PRERESONANCE RAMAN EFFECT, FORCE-FIELD AND THEORETICAL CALCULATIONS

Starting with ClSO2NCO and SbF3, fluorosulphuryl isocyanate, FSO2NCO, was Prepared. FT-IR data for the vapour and Raman spectra for the liqu id were obtained. The observed features and the pre-resonance Raman da ta are consistent with the existence of only one conformer possessing C1 symmetry both in the vapour and liquid phase. For all but the torsi onal mode of this rotamer, experimental wavenumbers are reported. Symm etry force constants were calculated using a torsional frequency taken from ClSO2NCO. The experimental studies were augmented by ab initio c alculations at various levels of sophistication (HF/3-21G, HF/6-31G*, MP2/6-31G). The predicted conformational properties for FSO2NCO are in good agreement with the experimental data.