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.