Amino-nitramino functionalized triazolotriazines: a good balance between high energy and low sensitivity

Abstract

Using a simple and efficient approach, a series of fused triazolo-triazine compounds, namely, 2,5-dinitramide-7-amino-[1,2,4]triazolo[1,5-a][1,3,5]triazine (2) and its energetic salts (4–9, 11–13), were prepared by nitration of 2,5,7-triamine [1,2,4]triazolo[1,5-a][1,3,5]triazine (1) with 100% nitric acid, followed by reacting with the corresponding bases. All new compounds were comprehensively characterized. Structures of 2 and 4 were further confirmed by single crystal X-ray diffraction. Based on the measured densities and calculated heats of formation (Gaussian 09), detonation pressures and velocities were evaluated by EXPLO5, falling in the range of 21.5–34.2 GPa and 7823–9313 m s⁻¹, respectively. Notably, impact and friction tests show that these compounds are very insensitive (IS > 40 J; FS > 360 N). Moreover, two representative compounds 5 and 6 with high decomposition temperature (5: 194 °C; 6: 199 °C), excellent detonation properties (v_D = 9313, 9088 m s⁻¹; P = 33.9, 34.1 GPa) as well as rarely low sensitivities (IS > 40 J; FS > 360 N) are promising candidates as high-energy and insensitive explosives.