From anion-centric to cation-enabled energetics: planar tetrazine frameworks with enhanced stability

Abstract

Nitrogen-rich heterocycles represent a fertile ground for novel reactions and unusual molecular conversions, which not only advance fundamental heterocyclic chemistry but also enable the design of next-generation energetic materials. Owing to their high energy densities and clean decomposition into environmentally benign nitrogen gas, such frameworks are of growing importance in energy and environmental science. We report a new class of tetrazine-derived cationic and zwitterionic frameworks that enable thermally robust, high-performance energetic salts suitable for advanced propellant and energetic applications. Unlike conventional anion-centric approaches, our design focuses on planar, high-nitrogen tetrazine cations that promote π–π stacking interactions, hydrogen bond networks, and compact layer-like packing. These structural characteristics yield thermal decomposition onsets of 163–320 °C, densities of 1.61–1.80 g cm⁻³, and calculated detonation velocities of 7866–9292 m s⁻¹ with corresponding detonation pressures of 21–34 GPa. Our zwitterionic tetrazine highlights how cation engineering and zwitterionic design together expand the scope of tetrazine chemistry toward thermally robust energetic materials. This work expands the scope of tetrazine chemistry and highlights the utility of planar high-nitrogen frameworks in the design of stable energetic materials.