Possible decomposition mechanisms of C nitro and N nitro 1,2,4 triazoles were simu lated. We showed that in addition to the experimentally detected thermolysis products includ ing N 2 , N 2 O, NO, CO 2 , HCN, HNCO, 1,2,4 triazole, 3(5) nitroso 1,2,4 triazole, and 1,2,4 triazolone, some other decompositon products (H 2 O, CO, NO 2 , cyanamide, cyanuric acid, and melamine) can be formed. Using the density functional approach (B3LYP/6 31G* approximation), we assessed the most favorable thermal decomposition pathways of nitro triazoles and studied the relationships between the thermolysis pathways of these substances and their molecular and electronic structures. We found a correlation between the energy gap width (energy difference between the frontier molecular orbitals) and the stabilities of the C nitro 1,2,4 triazole tautomers to thermal decomposition.

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We have analyzed the structural, electronic, and thermochemical characteristics and the enthalpies of formation for the compounds in the gas phase and in the solid phase. We have found a correlation between the strength of the N-N bond and the N-N bond length, the pyramidality of the nitrogen atom of the piperazine ring, and the size of the energy gap between the frontier orbitals. Based on calculations by the density functional method, we have carried out a comparative analysis of the thermochemical stability of the compounds in homolytic reactions.

An approach to simulate thermal destruction processes of energetic materials has been developed. It is based on the classification of structural features for nitro compounds and the experimental data regarding their decomposition mechanisms. This approach consists of the mathematical simulation of thermal decomposition mechanisms to predict the likely reactions that may occur during the destruction of organic compounds. On the basis of contemporary experimental data on the decomposition of energetic materials from various chemical classes, a set of semi‐empirical rules for modeling possible reaction pathways has been formulated. These rules allow the generation of a whole set of possible decomposition mechanisms for substances at different steps of their destruction. In this study, the suggested methodology is applied to 2,4,6,8,10,12‐hexanitro‐2,4,6,8,10,12‐hexaazaisowurtzitane (CL‐20) and hydrazine and to their binary energetic mixture. It has been shown that thermal decomposition of the binary system consists in decompositions of the separate compounds at the initial stage with subsequent collisions and interactions of the resultant intermediates and decomposition products at different stages. In addition to some experimentally found decomposition products, our simulation showed some other possible compounds among the final products.