ABSTRACT

The primary purpose of a supporting electrolyte (SE) salt is to regulate electrochemical cell resistance. Beyond serving this important function, the presence of the salt introduces a number of physical and chemical effects that inuence the redox mechanism of the analyte [1, 2]. An important chemical effect is that of ion-pairing interactions between the electrolyte ions and charged members of the redox couple, since these inuence both the redox potential and the solubilities of different ions of the redox couple. The additional, less benign possibility of an irreversible follow-up reaction between a redox product and an electrolyte ion has been of less concern owing to the relative inertness of the salts ordinarily used for molecular electrochemistry. Focusing on nonaqueous solutions, the traditional electrolyte salts consist of an organic cation, usually the tetraalkylammonium cation, [NR4]+, and an inorganic anion such as [ClO4]–, [BF4]–, [PF6]–, or [CF3SO3]–, the latter grouping referred to here as the traditional anions (TAs) [1, 2].