Computational studies on energetic properties of trinitro-substituted imidazole-triazole and pyrazole-triazole derivatives.

Heats of formation (HOFs) for 24 designed compounds were obtained by using the density functional theory (DFT). Molecular structures were investigated at the B3PW91/6-31G(d,p) level, and isodesmic reactions were designed for calculating the gas phase heats of formation. The solid state heats of formation for designed compounds were calculated by the Politzer approach using heats of sublimation. All the designed compounds possess solid state heats of formation above 140 kJ/mol. The distance between nitro groups influences the steric and repulsive interactions. Detonation performances were evaluated by the Kamlet-Jacobs equations based on the predicted densities and solid state heats of formation, and susceptibility of decomposition was studied by the computations of bond dissociation energy (BDE). Further, the present study might provide useful information for the structure-property relationship, the laboratory synthesis of imidazole-triazole and pyrazole-triazole based nitro derivatives and the development of novel high energy materials (HEMs).