Theory Of Electron Transfer Reactions Research Articles

On the Theory of Electron-Transfer Reactions. VI. Unified Treatment for Homogeneous and Electrode Reactions

A unified theory of homogeneous and electrochemical electron-transfer rates is developed using statistical mechanics. The treatment is a generalization of earlier papers of this series and is concerned with seeking a fairly broad basis for the quantitative correlations among chemical and electrochemical rate constants predicted in these earlier papers. The atomic motions inside the inner coordination shell of each reactant are treated as vibrations. The motions outside are treated by the ``particle description,'' which emphasizes the functional dependence of potential energy and free energy on molecular properties and which avoids, thereby, some unnecessary assumptions about the molecular interactions.

The Exchange of Iron between the Aquo Ferrous and Ferric Versenate Ions

Electron transfer in the ferrous Versenate-ferric Versenate exchange reaction occurs chiefly between the Versenate oomplexes of Fe(II) and Fe(III) and not between any dissociation produots of these complexes at pH 2. The electron transfer between the undissociated Versenate complexes of Fe(II) and Fe(III) probably occurs by tunneling. The exchange of Fe/sup 58/ between Fe/sup 2+/(aq) and FeYwas found to be slow, and this exchange was compared witu other electron- transfer reactions involving Fe/sup 2+/(aq) and ionic oxidants on the basis of Marcus' theory of electron-transfer reactions. (auth)