Theoretical study on initial decomposition paths of several [5,6,5]-tricyclic, [5,7,5]-tricyclic and [5,8,5]-tricyclic heterocyclic energetic materials based on fused ring

High energy materials based on fused ring are an important type of new energetic materials recently synthesized. However, its decomposition path has not received much attention. density functional theory (DFT) method is used to study the initial decomposition reaction paths of 12 high energy materials based fused ring. In addition to the conventional decomposition reaction, it is also found that the production of N-2 molecule by ring opening process, which is the lowest energy initial decomposition path with only 40 kcal/mol energy barrier among [5,6,5]-tricyclic heterocyclic energetic materials and also theoretically shows that such reactants are the most unstable and conform to the experimental data. In addition, it is also found that there is a novel reaction path for releasing N-2 by contraction of middle ring in the initial decomposition path of [5,7,5]-tricyclic and [5,8,5]-tricyclic heterocyclic energetic materials.