ELECTRON-TRANSFER REACTIONS IN ORGANIC-CHEMISTRY

The Intersecting-State Model (ISM) is used to calculated the absolute rate constants of self-exchange electron-transfer reactions (ET) of or ganic species. The systems studied include aromatic hydrocarbons, quin ones, nitrobenzene, aromatic nitriles, tetracyanoethylene, aromatic am ines, and alkylhydrazines. All of the calculated rates are within one older of magnitude of the experimental ones, and the correlation coeff icient between the two sets is 0.96. An electron-tunneling model has b een developed to calculate distance-dependent nonadiabatic factors of intramolecular ET. This model can be used with ISM to calculate intram olecular ET rates. The system biphenylyl-spacer-naphthyl in tetrahydro furan, whose distance-dependent intramolecular rates were measured by Closs and Miller, was used to test our calculations, because its ET ra tes can be calculated without adjustable parameters. Our absolute rate calculations are in an order-of-magnitude agreement with the experime ntal ones.