Unveiling the Dissociation Mechanism of Diglycine Perchlorate

Determining the dissociation mechanism of perchlorate materials remains a top priority to address sustainability, handling, processing, and synthesis issues of new and existing high-energy density materials vital to many industrial processes. We determined the dissociation mechanism of diglycine perchlorate (DGPCl) using vibrational spectroscopy, which unveiled the formation of ammonium perchlorate (AP) and carbon at high temperatures. Our studies establish that DGPCl shows multiple phase transitions upon heating. The reversible melting transition (∼100 °C) is characterized by reorientations in hydrogen bonding, thereby modifying glycine geometry. The irreversible liquid-liquid transition (∼170 °C) is guided by the dissociation of cationic glycine and the formation of an intermediate complex, showing a change in color. Above 240 °C, the liquid state transforms to a solid state with the evolution of H₂O, HCN, CO, CH₄, N₂O, CO₂, etc., gases, detected using high-resolution rovibrational and mass spectroscopy. Notably, no NH₃ release was observed, ruling out an earlier prediction. This results in the formation of AP, one of the strongest oxidizers, as residue enveloped by carbon layers, a potential fuel. The observed exothermic enthalpy above 240 °C is ∼405 kJ/mol. The discovery may pave the way toward finding better organic perchlorates with modified properties to mitigate challenges with the existing ones.