CONTRIBUTION TO THE INFRARED SPECTRA OF FIVE-MEMBERED N- AND N,S-HETEROCYCLIC COMPOUNDS

Infrared spectra of 5-membered N- and N,S-heterocyclic derivatives such as triazoles, tetrazoles, thiazoles, thiadiazoles, thiatriazoles, and dithiazoles have been examined and empirical assignments have been made. The spectra of the two dithiazolidine derivatives, isoperthiocyanic acid and oxidation product of dithiobiuret, have been studied in detail. Assignments for benzthiazole derivatives are reported. The CH out-of-plane deformation bands of benzene rings fused to five-membered heterocyclic rings have been found to be in the region 760–740 cm −1 , characteristic of four adjacent benzenoid hydrogen atoms.