Computational studies on the energetic properties of polynitroxanthines.

Density function theory calculations were performed to find comprehensive relationships between the structures and properties of a series of highly energetic polynitroxanthines. The isodesmic reaction method was employed to estimate the gas-phase heat of formation. The solid-state heats of formation for the designed compounds were calculated by the Politzer approach using heats of sublimation. All of the designed compounds were found to possess solid-state heats of formation of >100 kJ mol⁻¹. Detonation performances were evaluated by the Kamlet-Jacobs equations, based on the predicted densities and solid-state heats of formation. The results indicate that all of the compounds have excellent detonation velocities and pressures. The stabilities of the derivatives were calculated by evaluating their energy gaps, bond dissociation energies, and characteristic heights. The results indicate that all of the compounds have large bond dissociation energies and energy gaps. The characteristic height values of the compounds are more than or close to those of HMX and RDX. Thus, the polynitroxanthine derivatives show good thermodynamic and dynamic stability. Further, the present study may provide useful information on the structure-property relationships of these compounds, and for the development of novel high-energy materials.