Thermal behavior and evolved gases analysis of 1,2,4-triazole-3-one derivatives

In order to obtain a better understanding of thermal substituent effects in 1,2,4-triazole-3-one (TO), the thermal behavior of 1,2,4-triazole, TO, as well as urazole and the decomposition mechanism of TO were investigated. Thermal substituent effects were considered using thermogravimetry/differential thermal analysis, sealed cell differential scanning calorimetry, and molecular orbital calculations. The onset temperature of 1,2,4-triazole was higher than that of TO and urazole. Analyses of evolved decomposition gases were carried out using thermogravimetry-infrared spectroscopy and thermogravimetry-mass spectrometry. The gases evolved from TO were determined as HNCO, HCN, N(2), NH(3), CO(2), and N(2)O.