Electron transfer reactions studied through the transient effect in fluorescence quenching

Fluorescence quenching by high concentration (> 0.1M) of quencher causes nonexponential decay of fluorescence (the transient effect). Electron transfer reactions were studied by measuring the transient effect in fluorescence quenching. The rate parameters J0 (the transfer integral at a donor-acceptor separation of 6Å) and β (attenuation coefficient of the transfer integral) were determined by fitting the calculated decay curves to the measured ones. The distribution Y(r) of electron transfer distance is expressed in terms of the distance dependence of the rate constant, the quencher distribution function and the fluorescence decay curve. Y(r) was calculated using the values of J0 and β obtained experimentally. Finally, the distribution Y(r) was used to calculate the yield of free ions which are formed after charge separation reactions