Geminate recombination in excited-state proton transfer reactions: Numerical solution of the Debye-Smoluchowski equation with backreaction and comparison with experimental results

The well-known phenomenon of proton dissociation from excited-state hydroxy-arenes is analyzed by the Debye-Smoluchowski equation which is solved numerically with boundary conditions which account for the reversibility of the reaction. The numerical solution is then compared with the measured dissociation profiles which were obtained by picosecond time-resolved fluorescence spectroscopy. The intrinsic rate constants thus determined are used to predict steady-state rates, yields, and pK values, in agreement with experiment.