Intramolecular Photoinduced Electron Transfer in Pyromellitimide-linked Porphyrins

Characteristic absorption of the anion radical of pyromellitimide around 715 nm was demonstrated to be particularly useful for studies on photoinduced electron transfer reactions. Charge recombination in pyromellitimide-linked porphyrin was greatly retarded in benzene due to the large energy gap and small reorganization energy. A long-lived charge separated state (τ = 2.5 μs) was formed in the case of a diporphyrin-porphyrin-pyromellitimide triad system.