Triazene-bridged energetic materials based on nitrotriazole: synthesis, characterization, and laser-ignited combustion performance

Abstract

Compared to the widely concerned azo bridges (–NN–), triazene bridges (–NN–NH–) with longer nitrogen chains are also favorable linking units leading to novel energetic materials. In this work, a new family of nitrogen-rich nitrotriazolate-based energetic compounds with a triazene bridge were synthesized and well characterized. The experimental results indicated that most of these new compounds have good thermal stabilities and low sensitivities. Among these, ammonium 5,5′-dinitro-3,3′-triazene-1,2,4-triazolate (3) and potassium 5-nitro-3,3′-triazene-1,2,4-triazolate (7) decomposed at a relatively high temperature (240.6 °C for 3 and 286.9 °C for 7). The impact sensitivities of the obtained compounds ranged from 15 J to 45 J. They also have relatively high positive heats of formation between 667.5 to 817.3 kJ mol⁻¹. The calculated detonation pressures (P) were located between 23.7 and 34.8 GPa, and the calculated detonation velocities (D) were between 8011 and 9044 m s⁻¹. Interestingly, ammonium 5-nitro-3,3′-triazene-1,2,4-triazolate (8) and hydroxylammonium 5-nitro-3,3′-triazene-1,2,4-triazole (10) possessed excellent laser-ignited combustion performance.