Abstract

Bimolecular chemical reactions in solution are essentially a many-body problem. The conventional rate equation approach, which neglects the spatial distribution of the reacting particles, is satisfactory for intrinsically slow reactions. When reaction is diffusion controlled, competition between reacting particles introduces correlations in their diffusive motion. This should be manifested in the long-time dependence of the reactive concentrations. Physicists [1] have recently investigated the irreversible recombination reaction, A+B→AB, treating primarily the equal concentration and diffusion coefficient case, [A]=[B] and da = db. The situation is more complex when the reaction is reversible [2]. In the irreversible case, the process ends with the first binding event, while for a reversible reaction a recently bound AB molecule may subsequently dissociate to reproduce the A…B partners, thus altering their spatial distribution. After a few cycles of recombination/dissociation the initial distribution becomes irrelevant. One expects the densities to approach equilibrium, independently of the initial condition and by following an asymptotic law which itself should be independent of the initial distribution.

© 1992 The Author(s)