Utilizing 4-Nitro-1,2,3-triazole to Cap and Stabilize a Chain of Eight Consecutive Nitrogen Atoms

How to stabilize the metastable all/long catenated nitrogen atom system is a great challenge. In this work, a novel "aza-heteroaromatic-sealed" strategy to seal an unstable N10B structure by two 4-nitro-1,2,3-triazole scaffolds and obtain stable F-N10B [1,2-bis(5-(4-nitro-2H-1,2,3-triazol-2-yl)-2H-tetrazol-2-yl)diazene] under mild reaction conditions was exhibited. As a benefit from increased p-π interactions, non-classical hydrogen bonds (O···H-C), bond dissociation energy, and aromatic properties, F-N10B shows the best safety among the all reported N10-type energetic compounds (T_d = 160 °C, IS = 1.5 J, and FS = 7 N). Thus, almost all characterizations can be performed under ambient conditions (NMR, IR, elemental analysis, scanning electron microscopy, and single-crystal X-ray diffraction). This work successfully addressed the challenge of achieving stable termination for the highly unstable structure containing eight catenated nitrogen atoms, contributing to the advancement of the understanding in the discipline of metastable high-entropy and fully nitrogenous energetic materials.