Molecular Assemblies of Pyrazole-Tetrazole-Pyrimidine: Heat-Resistant Energetic Materials Engineered by π-Conjugation Extension and Directional Hydrogen-Bonding Synergy

The development of thermally stable explosives with simple synthesis and high performance remains a key challenge in energetic materials research. This study synthesized two nitrogen-rich heterocyclic compounds through structural conjugation strategies: tetrazole derivative 1 and nitro-pyrazole derivative 4. Both materials exhibited exceptional thermal stability (Td = 305 and 356 °C, respectively), comparable to benchmark materials TATB (Td = 350.0 °C) and HNS (Td = 318.0 °C). Their energetic performance showed balanced characteristics with detonation velocities (Dv) of 8553 m·s–1 (1) and 8607 m·s–1 (4), combined with low sensitivity (IS ≥ 35 J, FS = 360 N). Six high-energy derivatives (2, 3, 3–1 to 3–3, 5) were further developed based on these frameworks. The conjugation effects and hydrogen-bonding interactions revealed in this work establish a new design paradigm for achieving simultaneous optimization of thermal stability and detonation performance in advanced energetic materials.