Quantum chemical studies on the fused nitroazoles

In this study, fused nitroazoles based on imidazole, pyrazole, and triazole skeletons have been considered as potential candidates for high explosives by quantum chemical treatment. Geometric and electronic structures, band gap, thermodynamic properties, crystal density, and detonation properties have been studied using density functional theory (DFT) at the B3LYP/aug-cc-pVDZ level. The chemical energy of explosion (≈ 1.70 kcal/g), density (≈ 1.93 g/cm3), detonation velocity (≈ 9.30 km/s), and detonation pressure (≈ 40.00 GPa) of designed compounds are found to be superior to octahydro-1,3,5,7-tetranitro-l,3,5,7-tetraazacyclooctane (HMX), 3,6-dinitropyrazolo[4,3-c]pyrazole (DNPP), and 1,4-diamino-3,6-dinitropyrazolo[4,3-c]pyrazole (LLM-119). Presumably the relative positions of nitro groups determines the stability, sensitivity, and crystal density thus detonation performance.