Unraveling the initial decomposition of pyrazolo-triazine energetic materials: Roles of temperature and functional groups from first-principles calculations

Fused-ring energetic materials are increasingly being developed, and investigating their thermal decomposition reactions contributes to a better understanding of their thermal stability. Through first-principles molecular dynamics simulations, the thermal decomposition mechanisms of several pyrazolo-triazine fused-ring energetic materials (ICM-103, NAPTO, and BITE-101) was studied under different temperatures. Results indicate that the increase in temperature not only accelerated the decomposition rates but also led to more complex reaction pathways. Key initial decomposition pathways include N 2 release from azide groups, proton dissociation, ring formation/opening, and nitro dissociation, where proton dissociation is dominant in all compounds. Bond cleavage analysis showed that triazine ring bonds were more prone to break, especially the N-N bonds near the azide group. The main products such as N 2 , NO, N 2 O, and CO 2 showed a trend of temperature dependence. These results provided a deeper understanding of the thermal decomposition mechanism of fused-ring energetic materials and laid a foundation for the development of new energetic materials. Through first-principles molecular dynamics simulations, the thermal decomposition mechanism of ICM-103, NAPTO, and BITE-101 was studied under different temperatures.