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

Here, a series of azo-bridged high-energy materials (compounds <b>4-7</b>) based on a fused [1,2,4]triazolo[1,5-<i>b</i>][1,2,4,5]tetrazine scaffold were synthesized. Fused azo-bridged dinitramino compound <b>5</b> exhibits a high heat of formation of 5.38 kJ g^-1 and excellent detonation performance (<i>D</i>_v = 9795 m s^-1; <i>P</i> = 41.8 GPa), higher than that of benchmark explosive CL-20. Its energetic salts <b>6</b> and <b>7</b> exhibit good detonation performance (<i>D</i>_v = 8930 and 8878 m s^-1, respectively; <i>P</i> = 30.8 and 31.8 GPa, respectively) while displaying improved thermal stability. In addition, the thermal stability of compound <b>4</b> (<i>T</i>_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 <b>5</b> could serve as a potential candidate as a secondary explosive.