Vibrational frequencies and structural determination of selenium dithiocyanate

The vibrational frequencies and corresponding normal mode assignments of selenium dithiocyanate are examined theoretically using the gaussian03 set of quantum chemistry codes. Two conformers were found with C2 and Cs symmetry. A thermodynamic analysis shows that the two forms of selenium dithiocyanate have free energies that are very similar and that both forms would likely exist at appreciable concentrations at room temperature in the gas phase. All normal modes were successfully assigned to one of seven types of motion predicted by a group theoretical analysis (CN stretch, S-C stretch, Se-S stretch, S-CN bend, Se-S-C bend, S-Se-S bend, and S-Se-S-C torsion).