Vibrational relaxation in ionic liquids and ionic liquid reverse micelles

We report static and ultrafast IR studies of Fe(CN)5NO2− and W(CO)6 in bulk ionic liquids and of ionic liquid reverse micelles. For Fe(CN)5NO2− and W(CO)6 in ionic liquids, the vibrational frequencies appear to scale with solute-solvent interaction strength, but the vibrational energy relaxation (VER) times are longer than in methanol and DMSO. The VER times in the reverse micelles are consistent with a solvation environment that has mixed surfactant and ionic liquid and is more polar than the bulk ionic liquid. These results differ from previous ionic liquid reverse micelle studies.