Design, Synthesis, and Characterization of Novel, Nitrogen-Rich Fused Energetic Materials with High Energy, Low Sensitivity, and Thermal Stability

The development of high-energy yet low-sensitivity energetic materials is crucial for advancing next-generation energetic compounds with enhanced safety and performance. In this study, we report the design, synthesis, and comprehensive characterization of a novel class of nitrogen-fused tetrazole-based energetic compounds. These compounds were fully characterized using multinuclear nuclear magnetic resonance (NMR) spectroscopy, infrared (IR) spectroscopy, and elemental analysis, with their structures further confirmed by single-crystal X-ray diffraction. The resulting fused-ring energetic materials exhibit a well-balanced combination of thermal stability, detonation performance, and mechanical insensitivity. Notably, compounds 2, 5, and 6 demonstrate outstanding thermal stability (T_d ≈ 300 °C) while maintaining excellent detonation properties (D_v > 8000 m s^–1, P > 20 GPa). Compound 7 exhibits superior thermal stability (T_d = 331 °C), though its detonation performance is slightly lower, warranting further optimization. Additionally, compound 8 displays good thermal stability and detonation performance (T_d = 197 °C, D_v = 8108 m s^–1, P = 25.1 GPa). Importantly, all synthesized compounds exhibit significantly lower impact and friction sensitivities compared to RDX (IS > 7.5 J, FS > 120 N). These findings underscore the potential of nitrogen-rich fused-ring systems as promising candidates for high-energy, thermally stable, and insensitive energetic materials. This work provides valuable insights into the molecular design strategies for next-generation energetic materials with optimized performance and safety.