PHOTOINDUCED INTRAMOLECULAR ELECTRON-TRANSFER IN BISVIOLOGEN-LINKED PORPHYRIN IN ACETONITRILE

Bisviologen-linked porphyrin (p-PC4VAC4VB), in which two viologens are connected with porphyrin through methylene chain (-(CH2)4-) was prepared, and photoinduced intramolecular electron transfer between porphyrin and viologen was observed in acetonitrile. The photoexcited singlet state of the porphyrin was quenched by the bonded viologen due to photoinduced intramolecular electron transfer from the photoexcited singlet state of porphyrin to the bonded viologen. The rate constant of the intramolecular electron transfer was 3.10 X 10(8) s-1. The photoexcited triplet state was also quenched by the bonded viologen. The rate constant of intramolecular electron transfer via the photoexcited triplet state was 2.19 X 10(5) S-1.