Assembling properties of 3,6-dinitropyrazolo-[4,3-c]pyrazole-based energetic compounds

In pursuit of energetic materials with equal detonation properties and sensitivities compared to those of HMX and RDX, a series of 3,6-dinitropyrazolo-[4,3-c]pyrazole-based energetic compounds were designed, and density functional theory method was carried out to investigate the frontier molecular orbital, heats of formation, energetic properties, and impact sensitivities of the designed compounds. The results show that all the designed compounds possess high positive heats of formation range from 618.8 (A4) to 1934.3 kJ mol(-1) (E2) and the -N-3 energetic group was the most effective unit to improve the values of heats of formation. Values of oxygen balance of compounds E8 and F8 were zero and possess the most ideal oxygen balance. The calculated detonation properties indicate that the -C (NO2)(3) group was the most useful group to enhance the densities, detonation velocities, and detonation pressures. Nearly half of the designed compounds possess higher values of h(50) than RDX or HMX, which indicates that these compounds will be more stable than RDX and HMX. Based on detonation properties and impact sensitivities, five compounds (D3, D5, E5, F3, and F5) were screened as candidate compounds for high energy density materials. Finally, the distribution of the highest occupied molecular orbitals, the lowest unoccupied molecular orbitals, and electrostatic potential of the screened compounds were simulated to give an evident view on their physicochemical properties.