Theoretical studies on the thermodynamic properties, densities, detonation properties, and pyrolysis mechanisms of trinitromethyl-substituted aminotetrazole compounds.

Trinitromethyl-substituted aminotetrazoles with -NH₂, -NO₂, -N₃, and -NHC(NO₂)₃ groups were investigated at the B3LYP/6-31G(d) level of density functional theory. Their sublimation enthalpies, thermodynamic properties, and heats of formation were calculated. The thermodynamic properties of these compounds increase with temperature as well as with the number of nitro groups attached to the tetrazole ring. In addition, the detonation velocities and detonation pressures of these compounds were successfully predicted using the Kamlet-Jacobs equations. It was found that these compounds exhibit good detonation properties, and that compound G (D = 9.2 km/s, P = 38.8 GPa) has the most powerful detonation properties, which are similar to those of the well-known explosive HMX (1,3,5,7-tetranitro-1,3,5,7-tetrazocine). Finally, the electronic structures and bond dissociation energies of these compounds were calculated. The BDEs of their C-NO₂ bonds were found to range from 101.9 to 125.8 kJ/mol(-1). All of these results should provide useful fundamental information for the design of novel HEDMs.