Theoretical studies on nitrogen‐rich furoxan‐based heterocyclic derivatives

The density functional theory method was used to study the heats of formation (HOFs), energetic properties, electronic structure of a series of 4,4″‐dinitro(3,3′:4′,3′′)tris(1,2,5]oxadiazole)‐2′‐oxide (3,4‐bis4′‐nitrofurazan‐3′‐yl]furoxan) derivatives. The results show that the substitution of the nitro group is very useful for improving their HOFs and detonation performances. The HOFs of the title compounds are all positive and larger than those of 1,3,5‐trinitro‐1,3,5‐triazinane and 1,3,5,7‐tetranitro‐1,3,5,7‐tetrazocane. The analysis of oxygen balance shows that the studied compounds need the oxygen in the explosive. Compound A1 has larger detonation velocity and detonation pressure than those of 1,3,5,7‐tetranitro‐1,3,5,7‐tetrazocane and can be regarded as a potential candidate for high‐energy compounds because of the moderate heat of detonation, high density, and high N. In addition, the energy gaps between the highest occupied molecular orbital and lowest unoccupied molecular orbital of the studied compounds are further investigated.