The influence of 13C nuclei on quantum beats in the recombination luminescence of radical ion pairs undergoing ion-molecular charge transfer Original Research Article

The presence of 13C nuclei with high constants of hyperfine interaction (hfi) can change essentially the quantum beat frequency in some subensembles of recombining radical ion pairs. The corresponding disturbance of the total beat coherence due to the presence of 13C nuclei is increased by ion-molecular charge transfer processes. The theoretical investigation of a model system, described in the present paper, shows that under some conditions the ion-molecular charge transfer can even lead to an increasing beat decay decrement with increasing concentration of the reactant involved in the charge transfer. This is the case when due to the presence of 13C nuclei with high hfi constants in one of the radical ions its hyperfine structure (hfs) is splitted into widely spaced spectral groups. Averaging of this two-range hfs during ion-molecular charge transfer can be the reason for the unusual concentration dependence of the decay decrement of recombination luminescence beats of radical ion pairs.