The influence of the quencher concentration on the rate of simple bimolecular reaction: molecular dynamics study. II

In this paper new results of the simulations [M. Litniewski, J. Chem. Phys. 123, 124506 (2005)] on the influence of the quencher concentration on the reaction A+B-->C+B for the identical soft sphere system are presented. The problem is generalized by considering also the case when the spheres are immersed in the Brownian medium. A significant difference between simple deterministic systems and the Brownian ones is found: the excess in the rate coefficient for the Brownian system is constant and positive, except for very short times. The reaction has been simulated for a very long time, but any tendency to decrease the excess has not been noted. It is also shown that the relative excess in the surviving probability is a universal quadratic function of the quencher concentration for the range of time much longer than the result from the previous simulations. A very strong correlation between the excess in the relative value of spatial correlations between the reagents and the excess in the rate coefficient is shown. It is also shown that the A-A and A-C interactions have some influence on the excess values. A simple model for this effect is presented.