Superior thermally robust energetic materials featuring Z–E isomeric bis(3,4-diamino-1,2,4-triazol-5-yl)-1H-pyrazole: self-assembly nitrogen-rich tubes and templates with Hofmeister anion capture architecture

Abstract

A novel nitrogen-rich energetic material, namely 3,5-bis(3,4-diamino-1,2,4-triazole)-1H-pyrazole, was synthesized via a one-step reaction from commercially available reagents and its single-crystal X-ray analysis revealed that the conformational isomerism of this new energetic material was associated with the configuration of pyrazole (trans or cis) as a cation in the presence of two Hofmeister anions. Their structures were fully determined via¹H, ¹³C NMR, and infrared spectroscopies as well as elementary analysis. Single-crystal X-ray diffraction was employed for characterizing their crystal structures. It is worth noting that the detonation velocity and sensitivity (D: 9275 m s⁻¹, IS > 40 J, FS = 360 N) of 3,5-bis(3,4-diamino-1,2,4-triazole)-1H-pyrazole (EM3) are superior to those of RDX. Meanwhile, 3,5-bis(3,4-diamino-1,2,4-triazole)-1H-pyrazole and its supramolecular assembly energetic materials (EM3–EM5) exhibit great thermal stability (T_d: 280–358 °C), suggesting that they are also heat-resistant energetic materials. The above-mentioned energetic performances show that they are insensitive and have further potential applications as metal-free detonating substances.