Approaches to analytical and synthetic electrochemistry in fluorous solvent-containing media

The implementation of voltammetry in highly fluorous media has been demonstrated. Two strategies were utilized in order to overcome the major impediments to electrochemistry imposed by the low polarity of fluorous solvents. First, benzotrifluoride was used as a cosolvent with perfluoromethylcyclohexane in a 1-to-1 ratio to afford a fluorous mixture with a modest dielectric constant. Second, a fluorophilic supporting electrolyte was synthesized. The electrolyte consists of an imidazolium cation with a fluorous ponytail and the lipophilic tetrakis(3,5-trifluoromethyl)phenyl borate anion. The electrolyte medium allows for the routine electroanalysis of substrates using millimeter-sized electrodes. The electrochemical properties of ferrocene and a fluorous-ponytail analogue in the fluorous medium are given, and the ability to perform bulk electrolysis in the solvent mixture is demonstrated. The thermally regulated miscibility of fluorous and organic solvents is a particularly interesting phenomenon at present, and its applicability towards electrolysis-product purification is discussed.