High magnetic field dependence of lifetimes of methylene-chain-linked radical ion pairs (RIPs) generated by photo-induced electron transfer from zinc(II) porphyrin to viologen has been confirmed in aqueous acetonitrile using a pulse magnet-laser flash photolysis apparatus. In the case of a short methylene chain it was first revealed that the dependence was definitely different from that for a long one, and was characterized by a reversal in the dependence. In addition to a long lifetime independent of the magnetic field, RIP in fields above 7 T exhibited short lifetimes that depended on the field. These results were interpreted not only by spin-lattice (longitudinal) relaxation but also by spin-spin (transverse) relaxation in RIPs.
All Science Journal Classification (ASJC) codes
- Molecular Biology
- Condensed Matter Physics
- Physical and Theoretical Chemistry