Combining the advantages of 1,3,4-oxadiazole and tetrazole enables achieving high-energy insensitive materials

Abstract

Combining the advantages of energetic heterocycles to achieve high-energy insensitive explosives is a significant challenge. Herein, based on high-energy tetrazole rings and highly stable 1,3,4-oxadiazole rings, a series of novel nitrogen rich energetic compounds 5–9 were successfully constructed. The related compounds were fully characterized by EA, FT-IR, NMR, DSC, and MS, and compounds 6–9 were further confirmed by X-ray single crystal diffraction. Among them, the energetic ion salts 6–8 show high thermal stability (T_dec > 250 °C) and low mechanical sensitivity (IS > 40 J, FS > 360 N), as well as good energy properties (7552–8050 m s⁻¹, 19.4–23.3 GPa). In particular, the azo compound 9 exhibits competent comprehensive performances (T_dec = 226.2 °C, D = 8502 m s⁻¹, P = 28.9 GPa, IS = 32 J, FS = 320 N). These results suggest that the strategy of integrating tetrazole and 1,3,4-oxadiazole and employing an azo structure as a bridging unit are effective approaches to construct high-energy insensitive materials.