Assessment of Zwitterionic Strategies for Next-Generation Energetic Materials

The development of energetic materials with high power and low sensitivity has focused on zwitterionic compounds owing to their strong electrostatic and hydrogen-bonding interactions, which yield superior energy densities and reduced sensitivity. While several individual studies have highlighted advantages associated with zwitterionic energetic materials, these conclusions are generally based on comparisons with conventional energetic materials rather than with their corresponding non-zwitterionic analogues. This work presents the first systematic one-to-one comparison of key energetic and stability parameters of 17 experimentally reported and structurally diverse zwitterionic compounds and their non-zwitterionic counterparts. Our calculations reveal that zwitterionic compounds consistently exhibit superior densities, detonation velocities, and pressures compared to their non-zwitterionic counterparts. Crucially, the sensitivity and stability of non-zwitterionic and corresponding zwitterionic energetic compounds, predicted from the bond strength of C-NO2 and N-NO2 linkages, free space in the crystal lattice, binding energy, Mulliken net charge of the nitro group, and sphericity, showed that the zwitterionic form consistently guarantees lower sensitivity and better stability than that of the non-zwitterionic form. This study validates that zwitterionic architecture is a powerful strategy for enhancing energetic power and demonstrates that improved stability is an intrinsic characteristic of zwitterionic compounds.