On the Correlation of the Kinetics of Electron Transfer Processes with the Change in Reaction Free Energy. Application to Electron-Exchange Initiated Chemiluminescence Reactions.

摘要

The general electron transfer reaction mechanism proposed by Weller is analyzed for three specific cases: the electron transfer is exergonic and irreversible, the electron transfer is endergonic and reversible, and the electron transfer is endergonic and irreversible. In the last case it is revealed that the correlation of the log of the overall reaction rate constant with reaction free energy gives a line with a slope of -alpha/RT. The constant alpha is associated with the well-known transfer coefficient for electrode reactions. Analysis of the kinetics of chemically initiated electron-exchange luminescence (CIEEL) reactions reveals that they conform to the third case with alpha of ca. 0.3. Several other electron transfer reactions are suggested to be proceeding by this mechanism as well. (Author)