One-electron and two-electron transfers in electrochemistry and homogeneous solution reactions

This presentation has focused on the thermodynamic and kinetic aspects of one- and two-electron reactions in molecular electrochemistry. The thermodynamic features involve the standard potentials of the electron-transfer reactions and their dependence on the chemical structure of the reactants and products and the effects of the medium in which they are studied solvent, electrolyte. There is a very strong relation, on both a theoretical and practical basis, between chemistry and electrochemistry in the study and characterization of these electron-transfer reactions. The kinetics of the electron-transfer reactions are more difficult to interpret, in spite of abundant theoretical guidance. Nevertheless, giant strides have been made in understanding the rates of both electrode reactions and solution-phase electron-transfer reactions. This paper has focused almost exclusively on electron-transfer that is not coupled to various chemical reactions involving reactants and products. These of course are of great importance and are keys to the many applications of electrochemistry, for example, in electrochemical synthesis. It seems likely that knowledge of the fundamentals of electron transfer will continue to benefit our understanding of complete reactions, electron transfers plus coupled chemistry. © 2008 American Chemical Society.