The integration of dinitropyrazole and 1,3,4-oxadiazole: A novel hybrid heterocyclic skeleton for balancing energy and stability

In this study, a new energetic hybrid skeleton was constructed through the integration of nitropyrazole and 1,3,4-oxadiazole skeletons in a molecule. Furthermore, the energetic precursor (2), the azo-bridged compound (3), the neutral nitramine (4) and the corresponding energetic salts (5–7) were synthesized. Their physicochemical and energetic properties were experimentally and theoretically evaluated. Among the developed compounds, the azo-bridged compound (3) and dihydroxylammoinium (6) display high detonation performances (3, Dv = 8904 m/s, P = 34.47 GPa; 6, Dv = 9025 m/s, P = 34.66 GPa), moderate sensitivities (3, IS = 16 J, FS = 120 N; 6, IS = 20 J, FS = 312 N) and good densities (3, 1.87 g/cm3; 6, 1.81 g/cm3), which indicates that they have the potential to replace the traditional high-energy explosive RDX. The results showed that the integration of different energetic skeletons can achieve a good balance between energy and sensitivity.