Nitrogen-rich salts based on polyamino substituted N,N′-azo-1,2,4-triazole: a new family of high-performance energetic materials

Abstract

A new family of nitrogen-rich energetic salts based on 3,3′-diamino-4,4′-azo-1,2,4-triazole containing an N,N′-azo linkage has been synthesized and fully characterized by IR, ¹H and ¹³C NMR spectrum, elemental analysis, differential scanning calorimetry (DSC) and sensitivities toward impact, friction and electrostatics. The crystal structures of chloride 2, nitrate 3, perchlorate 4 and isomerization product 10 have been determined by single-crystal X-ray diffraction analysis. All the salts exhibit high thermal stabilities with decomposition temperatures of over 200 °C, except for nitroformate 6. The measured densities of salts 2–7 fall in the range of 1.71 to 1.99 g cm⁻¹. Theoretical performance calculations (Gaussian 03 and EXPLO5) provided detonation pressures and velocities for energetic salts in the ranges 26.3 to 45.7 GPa and 8042 to 9580 m s⁻¹, respectively. Moreover, these salts exhibit reasonable impact sensitivities (IS = 8–40 J) and friction sensitivities (FS = 90–360 N); these salts also exhibit excellent thermal stabilities, high detonation properties and reasonable sensitivities, which, in some cases, are superior to those of TNT, TATB and HMX, and present a favorable balance between the energy and stability of energetic materials. In addition, these salts exhibit excellent specific impulses (265 to 301 s), which make them competitive energetic materials.