Design, Synthesis, and Performance Modulation of Multifunctional Energetic Compounds Based on the 1,2,4-Oxadiazole Scaffold

Using 5-amino-1,2,4-oxadiazole-chloroxime as a key intermediate, a series of versatile 1,2,4-oxadiazole-derived energetic compounds were successfully synthesized. Among these high-energy materials, the dinitromethyl-functionalized compound 4 exhibited high mechanical sensitivity [friction sensitivity (FS) 120 N; impact sensitivity (IS) = 6 J], remarkable density (ρ = 2.13 g cm^–3), and promising energetic properties (D = 8424 m s^–1, P = 32.7 GPa), suggesting its potential as a primary explosive. Compounds 6–9, incorporating N-hydroxytetrazole moieties, demonstrated high thermal stability (165–229 °C), favorable detonation performance (8008–8404 m s^–1; 24.0–27.0 GPa), and low mechanical sensitivity (FS > 324 N; IS ≥ 40 J). Notably, the azo-bridged compound 10 displayed outstanding comprehensive properties (T_dec = 173 °C, D = 8519 m·s^–1, P = 29.5 GPa, FS = 240 N, and IS = 20 J) and exhibited typical secondary explosive characteristics. Compound 11 featured exceptionally stable mechanical sensitivity (FS = 360 N; IS = 36 J) coupled with a high decomposition temperature (T_dec = 264 °C). This study provides new insights into the application of 1,2,4-oxadiazole derivatives in the field of energetic materials.