Polynitro [1,2,4] triazolo [4,3-b] pyridazine: a building block for superior-performance energetic materials

Abstract

This unique study reports an effective strategy for constructing bicyclic fused ring frameworks. A series of polynitro [1,2,4] triazolo [4,3-b] pyridazine fused ring with nitrogen-rich NH 2 /NHNH 2 /NHOH groups were first synthesized by straightforward routes, and were characterized by chemical (NMR, MS, IR spectroscopy, and single-crystal X-ray diffraction) as well as experimental analysis (sensitivity towards friction, impact and DSC-TGA test). Their detonation properties (detonation velocity, detonation pressure, etc.) were predicted by the EXPLO5 program. These new polynitro fused-ring compounds were found to show high density, high decomposition temperature and acceptable impact and sensitivities, making them promising high-energy density materials (HEDM). The combination of excellent energetic properties (density: 1.969 g•cm -3 , V det : 9585 m•s -1 ; P CJ : 41.8 GPa) superior to those of HMX (1,3,5,7-tetranitrotetraazacyclooctane), low sensitivity (36 J, 324 N) and highlights compound 5 as the highest-performing bicyclic fused-ring energetic compound reported to date.Computational considerations of 5 and 2,4,6-triamino-1,3,5-trinitrobenzene (TATB) suggests that structural character leading to a good balance between energy and safety. This work supports the effectivity of combination of polynitro groups into the multi-ring planar skeleton and provides a generalizable design synthesis strategy for developing new HEDMs.