and 2479 cm -1 arising from the S-H stretch and peaks at 2667, 2997 and 3233 cm -1 all of which are associated with N-H stretching of N-H...O hydrogen bonded moieties. At 300 K the absorption peaks associated with the S-H and the lowest frequency N-H stretches broadens so there is one broad absorption band with two distinct absorption peaks at higher frequencies.