Microwave Synthesis and Properties of a Series of N-alkyl-N-methylimidazolium Chloride Ionic Liquids

Abstract

Seven N-alkyl-N-methylimidazolium chloride ionic liquids were synthesized under the organicsolvent- free condition with microwave irradiation. The structures were characterized and confirmed by ¹H NMR and melting points were determined by differential scanning calorimetry (DSC). Their surface tensions and water adsorption properties were measured at room temperature. The results showed that there was a decrease in surface tension and water adsorption with an increasing substituting alkyl chain length in the 1-position of N of the cation. However the melting points increased with an increasing substituting alkyl chain length of the N of the cation.