1,2,5-Oxadiazole-1,2,3,4-Tetrazole Based High Energy Materials: Molecule Design and Screen

A series of 1,2,5-oxadiazole-1,2,3,4-tetrazole based high energy materials were theoretically designed and investigated. Their heats of formation, detonation properties and thermal stabilities were calculated by isodesmic reactions, Kamlet-Jacobs equations and bond dissociation energies, respectively. The results show that all the designed compounds possess high positive heats of formation and the –N=N–/–N3 substituents were found to be more helpful in improving the heats of formation than other substituents. The change tendency of densities, detonation pressures and detonation velocities were approximately the same to each other which suggests that values of densities were the key parameter to detonation properties rather than other parameters. In view of bond dissociation energies, the –CN/–NH2 substituents will be helpful to improve the thermal stabilities of the designed compounds while the other substituents/bridges will decrease their thermal stabilities to some extent. Take detonation properties and thermal stabilities into consideration, six compounds (C7, D3, D7, F7, G7 and H7) were selected as potential high energy density compounds since they had higher detonation properties and thermal stabilities than those of RDX. Finally, electronic structures (such as distribution of frontier molecular orbitals and electrostatic potentials) of the selected compounds were simulated to give a better understanding of these compounds.