Replacing C-Nitro with C-Tetrazole: A Promising Strategy to Enhance the Detonation Performance and Stability of Explosives

The fully nitrated azole-based energetic materials are high in energy but unstable, which limits their practical applications. Tetrazole, with its high formation enthalpy and intrinsic acidic hydrogen, can react with nitrogen-rich bases, further enhancing both the formation enthalpy and stability. Consequently, we replaced the C-nitro group in fully nitrated 1,2,4-triazole with C-tetrazole, resulting in the synthesis of 1-(trinitromethyl)-5-nitroimino-3-tetrazole-1,2,4-triazole (TNTT, 4). The salts of 1-(dinitromethyl)-5-nitroimino-3-tetrazole-1,2,4-triazole (DNTT) were synthesized via a metathesis reaction with bases derived from silver salts. All of the newly prepared energetic structures (4 and 7–10) were characterized by using single-crystal X-ray diffraction. Among these compounds, salt 9 exhibited the best overall performance, with an elevated decomposition temperature (Td = 181 °C), and its mechanical stability (IS = 17.5 J, FS = 216 N) and detonation velocity (D = 9337 m s–1) surpassed those of HMX, making it a promising candidate for secondary explosives. Additionally, N2H5+ salt 8 and K+ salt 10 demonstrated low mechanical sensitivity (IS ≥ 27.5 J, FS > 360 N) due to the formation of hydrogen-bonded organic frameworks and metal–organic frameworks.