The mechanism of proton-assisted photoinduced electron transfer from porphyrins to quinones has been investigated by a combination of NMR, photo-CIDNP, laser flash photolysis, and UV-vis absorption techniques. In aromatic solvents containing trifluoroacetic acid, the electron-donor species was found to be the triplet state of the porphyrin dication rather than that of the free-base porphyrin itself. In addition, reaction of the porphyrin dication triplet state with the protonated quinone species QH+, rather than Q, was found to be responsible for the observed electron transfer and the resulting CIDNP signals.
ASJC Scopus subject areas
- General Engineering
- Physical and Theoretical Chemistry