Direct Correlation Between the H/D Exchange Reaction and Conformational Changes of the Cation in Imidazolium-Based Ionic Liquid–D2O Mixtures

We present a study on the effects of deuterated water on the conformational equilibria of the imidazolium cation in aqueous mixtures of imidazolium-based ionic liquids at room temperature. We provide spectroscopic evidence that the conformational dynamics of the imidazolium cation in D2O are directly related to the H/D exchange reaction of the C–H group at position 2 on the imidazolium ring. The relation is supported by comparing Raman spectra obtained from solutions prepared with H2O and D2O.