Evidence for diffusion-controlled electron transfer in exciplex formation reactions. Medium reorganisation stimulated by strong electronic coupling.
Diffusion-controlled rates of formation were found from the temperature dependence of apparent quenching rate constants for exciplexes, when the driving force of excited-state electron transfer -0.1 < deltaG(ET)* < +0.1 eV. This is inconsistent with the conventional mechanism of electron-transfer reactions, involving preliminary reorganisation of the medium and reactants, and provides strong support for the mechanism of medium reorganisation stimulated by strong electronic coupling of locally excited and charge-transfer states.
Kuzmin
Michael G
MG
Department of Chemistry, Moscow M. V. Lomonosov University, 119992 Moscow, Russia. kuzmin@photo.chem.msu.ru
Soboleva
Irina V
IV
Dolotova
Elena V
EV
Dogadkin
Denis N
DN