1-Methyl-3-Ethylimidazolium Hydrogen Dichloride: Synthesis and Application to the study of Protons in Ambient-Temperature Chloroaluminate Ionic Liquids

摘要

The syntheses of 1-methyl-3-ethylimidazolium hydrogen dichloride (ImHCl2) and its deuterium analogue (Im2HCl2) and their use as proton/deuterium donors in ambient-temperature chloroaluminate melts are described. The material exists as a liquid at room temperature and has been characterized by 1H NMR spectroscopy. ImHCl2 is itself an ambient-temperature molten salt composed of Im cation and HCl2 anion. The 2H NMR chemical shifts of species derived from Im2HCl2 in 1-methyl-3-ethylimidazolium chloride/aluminum chloride melts lead us to suggest that HCl interacts with second chloride in basic melt solutions, whereas it is more weakly complexed in acidic melt solutions. The quantitative addition of a proton by ImHCl2 is demonstrated by use of pulse voltammetry. Chloroaluminates; Proton containing molten salt. (jes)