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Summary: In the present work, some [1,2,4]triazolo[4,3‐b][1,2,4,5]tetrazine‐based high energy compounds were designed. The electronic structures, heats of formation (HOF), detonation velocities (D), detonation pressures (P), and thermal stabilities (BDEs) of the titled high energy materials were calculated at B3LYP/6‐311G (d,p) theoretical level of DFT method. Based on the calculated data, the frontier molecular orbital energy gaps were from 1.02 (B2) to 3.91 eV (A4), the values of HOF, D, P, and BDEs were from 1020.6 (A4) to 2286.3 kJ mol−1 (D2), from 6.52 (A1) to 9.44 km s−1 (D8), from 17.5 (A1) to 41.5 GPa (D8), and from 36.1 (D2) to 515.5 kJ mol−1 (B1), respectively. Take D, P, and BDEs into consideration, seven compounds (A8, B8, C8, D7, D8, E8, and F8) were screened as potential candidates for high energy materials due to their high detonation properties (D and P) and proper thermal stabilities. Finally, the electronic structures (such as distribution of frontier molecular orbitals and electrostatic potentials) were presented, which may provide a new research direction to high energy materials. [ABSTRACT FROM AUTHOR]

Density functional theory calculations at B3LYP/6‐311G(d,p) level were employed to investigate the relationships between the structures and properties of 3‐nitro‐1,2,4‐triazol‐5‐one based high energy density materials (HEDMs). The results show that all the designed compounds possess high positive heats of formation and the N3/NN substituents were found to be the effective structural units to improve the heats of formation. The calculated detonation velocities and detonation pressures indicate that substituting the XNO2/NN groups were very useful for enhancing the detonation properties of these designed compounds. In view of the bond dissociation energies of the weakest bonds, it reveals that most of the derivatives have acceptable thermal stabilities and the CN groups were beneficial to improve their thermal stabilities. Overall, the effects of the energetic groups on all the parameters combined with those of the different bridges. Compared to those of 1,3,5‐trinitro‐1,3,5‐triazinane and 1,3,5,7‐tetranitro‐1,3,5,7‐tetrazocane, four compounds (A7, B7, D7 and E7) were screened as possible HEDMs and their electronic structures were fully investigated to give better understanding of physicochemical properties and theoretical support for further experimental synthesis. [ABSTRACT FROM AUTHOR]

A new family of asymmetric oxadiazole based energetic compounds were designed. Their electronic structures, heats of formation, detonation properties and stabilities were investigated by density functional theory. The results show that all the designed compounds have high positive heats of formation ranging from 115.4 to 2122.2 kJ mol−1. −N− bridge/−N3 groups played an important role in improving heats of formation while −O− bridge/−NF2 group made more contributions to the densities of the designed compounds. Detonation properties show that some compounds have equal or higher detonation velocities than RDX, while some other have higher detonation pressures than RDX. All the designed compounds have better impact sensitivities than those of RDX and HMX and meet the criterion of thermal stability. Finally, some of the compounds were screened as the candidates of high energy density compounds with superior detonation properties and stabilities to that of HMX and their electronic properties were investigated. [ABSTRACT FROM AUTHOR]

Density functional theory was employed to investigate ten 1,2,4,5‐tetrahydro‐1,2,4,5‐tetrazine‐based energetic materials. The heats of formation and detonation properties were calculated by isodesmic reactions and Kamlet–Jacobs equations. The thermal stabilities and impact sensitivities were also estimated to give a better understanding of their decomposition mechanism. The results indicate that all of the designed compounds have high positive heats of formation ranging from 525.1 to 1639.1 kJ mol−1, moderate detonation properties (heats of detonation of 536.6 to 2187.6 cal g−1, theoretical densities of 1.48 to 2.32 g cm−3, detonation velocities of 7.02 to 12.18 km s−1, and detonation pressures of 19.8 to 75.1 GPa), and acceptable stabilities (bond dissociation energies of 0.8 to 104.9 kJ mol−1). Taking both the detonation properties and the stabilities into consideration, compounds A4 and B4 were finally selected as promising candidates of high‐energy‐density materials, as their detonation properties and impact sensitivities were superior to those of HMX. Additionally, the frontier molecular orbitals, electronic densities, electrostatic potentials, and thermal dynamic parameters of compounds A4 and B4 were also investigated. Computational insight: A series of 1,2,4,5‐tetrahydro‐1,2,4,5‐tetrazine‐based energetic materials are designed and investigated by DFT. Their heats of formation, detonation properties, thermal stabilities, and impact sensitivities are calculated accurately. Finally, compounds A4 and B4 are screened as potential candidates of high‐energy‐density materials, and their electronic properties are also simulated to give a better understanding of their physicochemical properties. [ABSTRACT FROM AUTHOR]