Vibrational studies of biomolecules. I. 2-Thiouracil

IR, far-IR and Raman spectra of 2-thiouracil are reported and interpreted. All the thirty normal modes could be assigned. The Raman spectrum and the vibrational assignments for all the thirty modes are reported for the first time. The ring breathing and Kekule stretching modes for 2-thiouracil are observed to have lower magnitudes when compared to those for uracil which could be due to the mass effect of the sulphur atom in place of the oxygen atom.