Synthesis and characterization of 1-(hydroxyethyl)-3-methylimidazolium sulfate and chloride ionic liquids

• Synthesis and characterization of 1-(hydroxyethyl)-3-methylimidazolium sulfate ionic liquid.
• FTIR/ATR spectroscopy study of 1-(hydroxyethyl)-3-methylimidazolium sulfate ionic liquid.
• The effect of the anion on the FTIR/ATR and the thermal properties.

We have used the imidazole as a starting compound for the preparation of a new ionic liquid 1-(hydroxyethyl)-3-methylimidazolium sulfate, with a yield of 98% in the two-steps synthesis. This new ionic liquid at room temperature exhibits a greater chemical activity. For the first step, we change the previous synthetic route using 2-chloroethanol as starting material, and with 1-methylimidazole to prepare the 1-(hydroxyethyl)-3-methylimidazolium chloride [EtOHMIM+][Cl−]. In the second stage, we have exchanged the anion Cl− with HSO4−. The ionic liquid shows reasonably high conductivity and thermal stability up to 340 °C. Our samples are characterized by 1H NMR, 13C NMR and FT-IR. The physical characteristics of the ionic liquid, such as solvation capacity were studied using a thermo-gravimetric Analyzer (NETZSCH DSC 204 F1) in the range of 40–400 °C. The results show that the ILs may be used as polyelectrolyte for electrochemical applications.

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