Electrochemistry of Ferrocene in Acetonitrile. Evidence for Irreversible Kinetic Behavior Due to Passive Film Formation

摘要

Montenegro and Pletcher have recently pointed out that measurement of the heterogeneous electron transfer rate constant of the ferrocene/ferrocenium couple at ultramicroelectrodes in acetonitrile solutions gives values that are several orders of magnitude larger than those measured at conventional electrodes. In addition, Bond et al. have pointed out that there is ambiguity in the interpretation of the electrochemical behavior of this couple in organic solvents. There are large discrepancies between the results from different workers on similar electrolyte/solvent systems which serves to show the difficulty in marking reliable measurements on this supposedly ideal electrochemical system. The situation is further confused since it has been proposed as a potential standard couple for non-aqueous electromechanical calibration. In his work on similar measurements on ferrocene/ferrocenium in acetonitrile at an ultramicroelectrode, Bond has discussed in detail several possible reasons for these discrepancies. Keywords: Reprints. (JES)