Wide-Band, Time-Resolved Photoacoustic Study of Electron-Transfer Reactions: Photoexcited Magnesium Porphyrin and Quinones

Article abstract of DOI:10.1021/j100134a009

Wide-band, time-resolved, pulsed photoacoustics has been employed to study the electron-transfer reaction between a triplet magnesium porphyrin and various quinones in polar and nonpolar solvents.The reaction rate constants are near encounter limited.The yield of triplet state is 70percent in both solvents.The yield of ions is 85percent in the former and zero in the latter, in agreement with spin dephasing time and escape times from the Coulomb wells in the two solvents.In methanol the plot of measured heat output versus quinone redox potential is linear.This implies that the entropy of electron transfer is constant through the series, but it may not be negligible.