Nitrogen-Rich Substituent Engineering of [1,2,4]Triazolo[1,5- a ]pyrimidines for Balancing Energetic Performance and Stability

Abstract The development of energetic materials combining high energy output with high thermal and mechanical stability remains challenging. Here, we construct a series of [1,2,4]triazolo[1,5-a]pyrimidine-based energetic compounds (4–9) bearing diverse nitrogen-rich substituents through C–N bond formation. Compound 6 exhibits a detonation velocity of 8869 m s–1, which is comparable to that of the benchmark explosive RDX (8836 m s–1), while 4–9 show high decomposition temperatures of 270–330 °C and excellent mechanical insensitivity (IS > 40 J and FS > 360 N). Electrostatic potential and interaction region indicator analyses reveal that nitrogen-rich substituents and the resulting intermolecular interactions contribute to the enhanced stability. These results demonstrate that nitrogen-rich substituent engineering provides an effective approach to balancing energetic performance and stability, offering a molecular design strategy for insensitive, high-energy-density energetic materials.