Vibrational analyses of vinylsulfonamide CH2CHSO2NH2

The structure and conformational stability of vinylsulfonamide CH2 CH SO2NH2 were investigated by DFT-B3LYP/6-311 + G** and ab initio MP2/6-311 + G** calculations. From the calculations the molecule was predicted to exist predominantly in the gauche-syn (vinyl group nearly eclipses one of the S O bonds and the NH2 and the SO2 moieties eclipse each other) conformation with the possibility of low abundance of the cis-syn and the gauche-anti forms. The asymmetric potential function for the internal rotation about C S bond was determined for the molecule. The vibrational frequencies were computed at DFT-B3LYP level for the gauche-syn conformer of the molecule and its d2(C2H3 SO2ND2) and d3(C2D3 SO2NH2) deuterated species. Normal coordinate calculations were then carried out and the potential energy distributions were calculated for the molecule.