Thermodynamic Study of Decomposition Reactions of Cyanuric Triazide Explosive Using Density Functional Theory

Cyanuric triazide is an environmentally friendly explosive organic compound that can be used as a primary explosive in the construction of detonators. The decomposition of this compound produces a number of high-energy nitrene intermediates. This compound is decomposed after the explosion under vacuum into molecular nitrogen and cyanogen. In this article, the density functional theory (DFT) and B3LYP/6-311++G(2d,p) method were used for the thermodynamic study of decomposition reactions of cyanuric triazide. The thermodynamic constants such as total energy, internal energy, enthalpy, entropy, and Gibbs free energy were calculated for these reactions in the gas phase and solution. A range of solvents with different polarities was studied. Also, the effect of temperature on the thermodynamic constants of the reactions was investigated. The results showed that decomposition reactions of cyanuric triazide to nitrene intermediates are endothermic, while decomposition to cyanogen is very exothermic. All of these reactions are associated with increasing entropy (increasing disorder) and decreasing Gibbs free energy (spontaneous) across the reaction. The ΔG value of all reactions decreased with increasing temperature, which indicates the progress of reactions at higher temperatures.