Conjugated Pyrazole-Triazole/Oxadiazole Derivatives via Nitro Functionalization: Toward High-Performance Energetic Materials

Through the strategic integration of 3,4-dinitropyrazole with trinitromethyltriazole and oxadiazolone units, two novel asymmetric bicyclic energetic materials, 5-(3,4-dinitro-1<i>H</i>-pyrazol-5-yl)-3-(trinitromethyl)-1<i>H</i>-1,2,4-triazole (<b>DNP-TNF</b>) and 3-(3,4-dinitro-1<i>H</i>-pyrazol-5-yl)-1,2,4-oxadiazol-5(4<i>H</i>)-one (<b>DNP-OO</b>), were successfully designed and synthesized. Systematic testing revealed that the nitro-functionalized extended conjugated structure achieves excellent detonation performance (<i>D</i> = 9273 and 8485 m·s^-1, <i>P</i> = 39.4 and 31.3 GPa) while maintaining moderate thermal stability (<i>T</i>_dec = 150.7 and 198.5 °C) and mechanical sensitivity (IS = 8.9 and 12 J, FS = 168 and 240 N). Furthermore, <b>DNP-OO</b> exhibits a suitable melting point (<i>T</i>_m = 82.2 °C) and decomposition temperature, demonstrating its potential as a candidate for melt-cast explosive applications.