Salt formation: route to improve energetic performance and molecular stability simultaneously

A series of bicyclic energetic salts are prepared through the combination of one nitramino-based anion and six nitrogen-rich cations. All new compounds were well characterized by IR and multinuclear NMR spectroscopy, thermal analysis, elemental analysis, and single crystal X-ray diffraction analysis. As supported by experimental and theoretical data, salt formation causes the increase of the trigger bond dissociation enthalpies, significantly improving the thermal performance from 111 °C (the neutral compound) to 175-235 °C (organic energetic slats). Further, electrostatic surface potentials are employed to better understand their bond stabilities and noncovalent interactions (hydrogen bonds and π-π interaction) are calculated to illustrate the interactions between molecules before and after salt formation. All these results indicate that salt formation is an effective and facile strategy to improve the energy (heat of formation and detonation performance) and safety (thermal stability and mechanical sens...