A facile strategy for synthesizing promising pyrazole-fused energetic compounds

A novel hydrazine-functionalized strategy is utilized for the synthesis of pyrazole-based energetic materials, giving rise to a new family of pyrazole-fused compounds and N-nitramine compounds with excellent properties. These new energetic materials are fully characterized by IR, ¹H and ¹³C NMR and elemental analysis, as well as further confirmed by single crystal X-ray diffraction. All compounds exhibit high densities (1.816–1.882 g cm⁻³), good detonation properties (8323–8935 m s⁻¹) and low sensitivities (IS > 15 J). Among these compounds, pyrazole-fused compound 5 features a striking thermal decomposition temperature of 302 °C and a better integrated energetic performance (D = 8935 m s⁻¹, IS > 20 J, FS = 360 N) than that of RDX (D = 8795 m s ^-1, IS = 7.5 J, FS = 120 N). Furthermore, the results of detonation tests support the fact that 5 could be used as an applicable heat-resistant explosive and a replacer of HNS.