Reaction-yield-detected magnetic resonance in the intra-and intermolecular electron transfer reactions

The spin dynamics of the intermediate radical ion pairs formed in the intra-and intermolecular electron transfer reactions between N,N-dimethylaniline and phenanthrene is studied by employing the polymethylene-linked and nonlinked systems. Reaction-yield-detected magnetic resonance (RYDMR) experiments are performed by monitoring the exciplex fluorescence. From the theoretical consideration of the data, we conclude that the lifetime of the radical ion pair in the linked system is shorter than that in the nonlinked system. This tendency is opposite to what is generally observed in linked and nonlinked neutral biradical.