High-Energy Azo-Bridged Dinitramino Materials Featuring a Planar Fused [1,2,4]Triazolo[1,5- b ][1,2,4,5]tetrazine Scaffold

Here, a series of azo-bridged high-energy materials (compounds 4-7) based on a fused [1,2,4]triazolo[1,5-b][1,2,4,5]tetrazine scaffold were synthesized. Fused azo-bridged dinitramino compound 5 exhibits a high heat of formation of 5.38 kJ g^-1 and excellent detonation performance (D_v = 9795 m s^-1; P = 41.8 GPa), higher than that of benchmark explosive CL-20. Its energetic salts 6 and 7 exhibit good detonation performance (D_v = 8930 and 8878 m s^-1, respectively; P = 30.8 and 31.8 GPa, respectively) while displaying improved thermal stability. In addition, the thermal stability of compound 4 (T_d = 271 °C) is comparable to that of a classic heat-resistant explosive HNS while exhibiting a superior energetic performance. The results indicate that compound 5 could serve as a potential candidate as a secondary explosive.