Integration of Pyridine and Tetrazole into Hydrogen Bond Networks for Advanced Heat-Resistant Explosives

For decades, the core research direction of heat-resistant explosives has been the development of high-energy and high-safety materials. In this study, a series of novel energetic molecules were synthesized featuring five-membered nitrogen heterocycles, pyridine rings, and integrated ortho-amine-nitro hydrogen bond networks. Notably, 3,5-dinitro-N2-(1H-tetrazol-5-yl)pyridine-2,4,6-triamine (BTH-1) exhibits the highest onset thermal decomposition temperature (Td = 345 °C, D = 8902 m s–1) among tetrazole-based high-energy explosives, with a detonation velocity reaching HMX (Td = 279 °C, D = 9144 m s–1), while possessing low sensitivity and ease of synthesis. These excellent comprehensive properties confirm that BTH-1 is a highly promising heat-resistant explosive and has the potential to replace HNS (Td = 318 °C, D = 7612 m s–1). To further elucidate the underlying reasons for exceptional heat resistance as a tetrazole-based high explosive, an in-depth investigation was conducted on how nitrogen-rich tetrazole-containing compounds influence the thermal stability and detonation performance of target molecules with the expansion of their hydrogen bond networks. The results show that with the expansion of hydrogen bond networking, the molecules exhibit better aromaticity and C-NO2 bond strength, thereby endowing BTH-1 with excellent thermal stability. This work is expected to promote more research on the promising strategy of introducing nitrogen-rich tetrazole rings and hydrogen bond networks in molecular design and provide guidance for the development of advanced heat-resistant explosives.