Description of bimolecular photoreaction kinetics on the heterogeneous solid surface

A kinetic model including the surface distributions of both radiative and nonradiative (bimolecular) rate constants has been proposed for explanation of bimodal distribution curves of apparent rate constants of bimolecular pyrene fluorescence quenching by N,N-dimethylaniline on a nonporous silica surface. Assuming that the distributions of radiative and nonradiative rate constants are uniform functions, the analytic solutions of the generalized integral equation for the decay profile and average lifetime of the fluorophore excited state have been derived. The average values and mean-square deviations for both distributions have been determined for the bimolecular pyrene fluorescence quenching on the silica surface. The proposed model may be used as a basis for detailed studies of regularities in bimolecular photoreactions on the heterogeneous solid surface.