Triazoles. Part XII. Structure of 1,2,4-triazolinethiones
Abstract
Spectroscopic differences between N2-substituted 1,2,4-triazolinethiones and isomers substituted on N1 or N4 establish the 1H-1,2,4-triazoline-5-thione structure for N-unsubstituted 1,2,4-triazolinethiones. The spectroscopic differences are due to zwitterion contributions of longer and shorter charge separation respectively. The anomalous spectrum of 4-(4-pyridyl)-1,2,4-triazoline-5-thione may be explained in the same manner.