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Updated: Jan 30, 2026
Dynamic Electrochemical Measurement of Chloride Ions
Published on: February 5, 2016
Magnetic field effect on ion pair dynamics upon bimolecular photoinduced electron transfer in solution
Serguei V Feskov1, Marina V Rogozina1, Anatoly I Ivanov1
1Volgograd State University, University Avenue 100, Volgograd 400062, Russia.
Abstract:
The dynamics of the ion pairs produced upon fluorescence quenching of the electron donor 9,10-dimethylanthracene (DMeA) by phthalonitrile have been investigated in acetonitrile and tetrahydrofuran using transient absorption spectroscopy. Charge recombination to both the neutral ground state and the triplet excited state of DMeA is observed in both solvents. The relative efficiency of the triplet recombination pathway decreases substantially in the presence of an external magnetic field. These results were analyzed theoretically within the differential encounter theory, with the spin conversion of the geminate ion pairs described as a coherent process driven by the hyperfine interaction. The early temporal evolution of ion pair and triplet state populations with and without magnetic field could be well reproduced in acetonitrile, but not in tetrahydrofuran where fluorescence quenching involves the formation of an exciplex. A description of the spin conversion in terms of rates, i.e., incoherent spin transitions, leads to an overestimation of the magnetic field effect.
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