The Degradation of the 2-Hydroxyethylhydrazinium Nitrate Ionic Liquid System

The mechanism by which the 2-hydroxyethylhydrazinium nitrate (HEHN) ionic liquid (IL) dissociates via the formation and loss of nitric acid is investigated utilizing the effective fragment potential (EFP) method and various <i>ab initio</i> methods. Additionally, the interactions that dictate the stability of the HEHN IL and contribute to the formation of nitric acid are further assessed using the quasi-atomic orbital (QUAO) bonding analysis. From this work, it is suggested that the formation of nitric acid is dictated by the presence of hydrogen-bonding interactions which appear to become increasingly ionic in nature as the system approaches the bulk, limiting the formation of nitric acid.