Effect of Different Substituents on the Properties of 4-R-1,5-Diaminotetrazolium Pentazolate Salts

To explore the impact of different substituents (R) in 4-R-1,5-diaminotetrazolium cations on the performance of their pentazolate salts, five types of pentazolate salts with different groups were designed: -H, -OH, -NH2, -NH-NH2, and -N3. Quantum chemical methods were employed to deeply study the interionic interactions and detonation properties of these 4-R-1,5-diaminotetrazolium pentazolate salts. Among these five ionic compounds, the 1,5-diamino-4-hydroxytetrazolium pentazolate ([DAT-OH+] [N5−]) system exhibited the lowest interaction energy and highest stability, while the 1,5-diamino-1H-1,2,3,4-tetrazolium pentazolate ([DAT-H+] [N5−]) system was the least stable. Symmetry-adapted perturbation theory (SAPT) analysis indicated that electrostatic and dispersion effects predominantly contributed to these interactions. An independent gradient model based on Hirshfeld partition (IGMH) analysis further highlighted the interionic interaction regions, revealing extensive van der Waals interactions and the formation of N-H…N type hydrogen bonds. The hydrogen bond formed by the cyclo-N5− and hydroxyl groups was relatively strong, while other hydrogen bonds were weaker. Benefiting from a higher enthalpy of formation, the 1,5-diamino-4-azidotetrazolium pentazolate ([DAT-N3+] [N5−]) compound exhibited the highest detonation performance (D: 9295.77 m·s−1; P: 32.13 GPa), while [DAT-OH+] [N5−] also demonstrated good performance and stability (D: 8924.96 m·s−1; P: 28.85 GPa).