Solute–solvent interactions in imidazolium camphorsulfonate ionic liquids

Abstract

We directly observe the interaction between 1-butyl-3-methylimidazolium (bmim) or 1-butyl-2,3-dimethylimidazolium (bm₂im) and the solute, ethyl acrylate (EA), which is the popular dienophile in the Diels–Alder reaction and an H-bonding acceptor, by using specially designed electrospray mass spectrometry. In imidazolium ionic liquids, cation–anion interactions are controlled by selecting the appropriate anion, and the naked C₂–H of imidazolium, which loosely interacts with its counterion, can readily interact with an H-bonding acceptable solute. The ion–counterion (solvent–solvent) interaction affects the ion–solute (solvent–solute) interaction. This relation is one of the key criteria for selecting the cation–anion combination in tailoring ILs.