Electron and ion transfer potentials of ferrocene and derivatives at a liquid-liquid interface

Abstract

The electrochemistry of ferrocene, dimethyl ferrocene and decamethyl ferrocene at the interface of immiscible electrolytes has been investigated. The aqueous redox electrolyte was the hexacyanoferrate couple. It has been found that the study of the electron transfer reaction can be complicated by both the transfer of the ferricenium ion formed in the organic phase (1,2-dichloroethane) during oxidation, and by oxidation of the organic base electrolyte anion. However, by using a high concentration of aqueous electrolyte, the difference between ionic and electronic transfer potentials can be increased sufficiently to observe these two processes separately. Ionic transfer potentials of the ferricenium ion have been measured by preparing the corresponding FeCl − 4 salts. For decamethyl ferrocene, no electron transfer reaction could be observed at the liquid/liquid interface and it is proposed that this is due to distance effects, which become more marked for this more hydrophobic ferrocene derivative.