Asymmetric functionalized modification of bi(1,2,4-triazole) towards high-energy insensitive materials†

An asymmetric strategy is a constructive means to regulate the energy and properties of energetic materials. In this work, a series of asymmetric energetic compounds based on bi(1,2,4-triazole) were designed and synthesized, and the related structural features and performances were systematically investigated by NMR spectroscopy, FT-IR spectroscopy, MS, EA, and DSC for their impact on asymmetric functional groups. Among them, a single trinitromethyl group-modified energetic compound termed “TNBN” was confirmed by X-ray single-crystal diffraction analysis. Benefiting from the asymmetric trinitromethyl groups, the structure of TNBN showed a unique stacking pattern, and exhibited good detonation performance (8787 m s⁻¹ and 31.1 GPa) and acceptable insensitivity to mechanical stimuli (IS = 30 J and FS = 288 N) compared with its similar symmetric counterparts. This work aids understanding of the structure–performance relationship of asymmetric energetic compounds and demonstrates that appropriate modulation of the asymmetric trinitromethyl group is an effective approach to achieve high-energy insensitive energetic materials.