Synthesis of Two Series of Isomeric Triazolo-Triazine Fused Energetic Salts: High Thermal Stability, Insensitivity, and High Performances

In recent years, the safety of energetic materials has attracted more and more attention. How to design and synthesize heat-resistant and insensitive energetic materials has become an urgent problem to be solved. In this work, two series of energetic salts based on isomeric triamino triazolo-triazine fused-ring compounds were designed and synthesized by incorporating oxygen-rich anions (such as NO₃^- or ClO₄^-) with nitrogen-rich energetic cations. All of the new compounds were fully characterized by infrared (IR) spectroscopy, nuclear magnetic resonance (NMR), elemental analysis, and differential scanning calorimetry (DSC). Decomposition temperatures (T_d) of isomeric perchlorate salts 3 and 9 are 315 and 364 °C, respectively. Their different properties, densities and molecular stabilities are rationally explained based on crystal structures and packing patterns. Meanwhile, perchlorate 9 has the highest decomposition temperature and good detonation performance (D = 8485 m s^-1, P = 27.7 GPa), which is superior to HNS and PYX and suggests that it could be applied as a heat-resistant insensitive explosive.