Solvent effects of ionic liquids: investigation of ferrocenes as electrochemical probes

The redox potentials of ferrocene and decamethylferrocene were determined in a number of molecular and ionic solvents and used as a probe for polarity of room temperature ionic liquids (ILs). No macroscopic solvent property is simply related to redox potentials. Single empirical solvent parameters also are not able to describe the differences in potentials. Instead, Kamlet–Taft multiparameter relationship fits well ferrocenes redox potentials variation, with both molecular solvents and ILs, well describing specific solvent–solute interactions with the two probes. Copyright © 2010 John Wiley & Sons, Ltd.