Radical pair dynamics in micelles investigated by Monte Carlo simulations

Abstract

The reencounter functions (conditional probability densities of first reencounter) of radical pairs are central quantities for the calculation of CIDNP (chemically induced dynamic nuclear polarization) effects. A computer program was developed to obtain the reencounter functions of radical pairs and radical ion pairs in micelles by Monte Carlo simulations of diffusional trajectories. With these computer experiments, the influence of micelles on the radical pair dynamics was investigated. By varying the initial locations it was found that unless at least one of the radicals starts its diffusional trajectory extremely near the micelle boundary the reencounter function is essentially the same as in the case of free diffusion. It was concluded that pronounced changes of the reencounter function occur only if the boundary disturbs the short-time diffusional motion.