Long-term and short-term asymptotes of reaction rate constants in the presence of reactivity anisotropy

Based on the general theory of bimolecular multistage diffusion-influenced chemical reactions proceeding from different sites in solutions available in literature some general model of reactivity anisotropy is formulated. It treats active patches on the surfaces of rigid spheres as sites and, in the general case, includes into consideration relative translational motion of reactants and their rotational relaxation. For this model, general expressions are obtained for averaged free resolvents necessary for calculation of rate constants of multistage multisite diffusion-influenced reactions. Using these expressions, both short-term and universal long-term asymptotes of non-stationary rate constants of multistage multisite reactions have been found, and the time range of their applicability has been discussed.