Toward Ultrathermally Stable and Low-Sensitivity Energetic Materials Based on a Fused [5/6/5]-Tricyclic Backbone

Nowadays, thousands of heat-resistant compounds have been synthesized, yet few compounds can achieve a thermal stability of 400 °C and a detonation velocity of 8000 m·s^-1 and remain relatively insensitive to impact. This work reports the synthesis of advanced 5/6/5-fused energetic materials by introducing 1,2,4-triazine rings through an intramolecular integration strategy. The resulting fused-tricyclic compound NOANT was obtained by the cyclocondensation between carbohydrazide and amidoxime derivatives, followed a cyclization reaction between bromine cyanide and N-NH₂ in an N-heterocycle. NOANT demonstrates exceptional thermal stability (T_d = 401 °C), moderate detonation performance (D_V = 8218 m·s^-1), and low sensitivity (IS > 40 J, FS > 360 N), surpassing that of TATB (T_d = 360 °C, D_V = 8179 m·s^-1), making it a potential candidate for ultraheat-resistant explosives. These findings contribute to the advancement of ultraheat-resistant explosive materials.