Synthesis, Spectroscopic and Thermal Characterization of Azido-1,2,4-triazoles: A Class of Heteroarenes with a High Nitrogen Content

The syntheses of azido-1,2,4-triazoles 15 were carried out from triaminoguanidine hydrochloride and a carboxylic acid (formic, acetic, 2,2,2-trifluoroacetic, 2-benzylacetic, monochloroacetic acid) by a three-step synthetic route and were analyzed by accelerating rate calorimetry (ARC). The thermal decomposition of 15 was studied theoretically by using CHETAH and T1 software, and experimentally by using DSC to obtain kinetic data. Numerical modelling and mass spectrometry were also performed to estimate the nature of the intrinsic molecular reactivity of 15 and the possible early stages of a self-heating process. Complete optimization by using HF, B3LYP and MP2(full) methods at the 6-31G* level were performed on significant tautomeric forms of the azido-triazoles to confirm the electronic structures that were obtained by EI-MS.