Ion-molecular charge transfer reactions of hexafluorobenzene and cis-decalin in nonpolar solutions studied by linewidth broadening in MARY spectra

The effect of an external magnetic field on the radiofluorescence arising from the recombination of spin-correlated radical ion pairs (MARY spectrum) has been studied for dilute nonpolar solutions of hexafluorobenzene and cis-decalin. MARY spectra of these systems show additional local fluorescence intensity maxima at zero field and in the field equal to triple the hfi constant. The breaking down of spin coherence in the course of the ion-molecular charge transfer reaction leads to broadening of the maxima. Relations between the line broadening and the rate of charge transfer reaction have been derived. Rate constants of charge transfer reactions for hexafluorobenzene radical anion in squalene and cis-decalin radical cation in hexane have been obtained experimentally.