Tuning the Energy and Stability of Compounds by Functional Group Modification in 1,2,4-Triazole Derivatives

Balancing the energy and stability is a key challenge in the design of energetic materials. In this work, a series of novel compounds were synthesized by introducing varying numbers of nitro groups through precise modifications to the 1,2,4-triazole skeleton. Comparative studies demonstrated that tuning nitro groups in metastable structural moieties optimized the oxygen balance and enhanced stability while maintaining favorable detonation performance. Specifically, compound N-(5-nitro-3-(trinitromethyl)-1,2,4-triazol-1-yl)nitramide (NT-2) was obtained as solvent-free single crystals with a high density of 1.92 g cm^-3 through a regioisomeric approach. Compound 3-(dinitromethyl)-5-nitro-1,2,4-triazol-1-amine (NT-7) possesses a high thermal decomposition temperature of 179 °C and low mechanical sensitivity (FS = 128 N and IS = 23 J). Its detonation performance (V_D = 8990 m s^-1 and P = 35.6 GPa) is superior to that of RDX. Ignition experiments revealed that the type and number of nitro groups significantly affect the ignition behavior. Furthermore, a novel hydrolysis route was developed for the preparation of FOX-7 from gem-dinitro-substituted 1,2,4-triazole. This work could provide new insights into the energetic performance and structural design of energetic materials.