Photoinduced electron transfer in porphyrin-quinone cyclophanes, 7. Porphyrin-quinone cyclophanes with gradually varied acceptor strength: Physical properties related to electron transfer

Absorption and emission spectra of the doubly quinone-bridged porphyrin cyclophanes 1–4 with gradually varied acceptor strength as well as of the single-bridged analogues 5–9 and 10–13 are reported. Reduction and oxidation potentials of these intramolecular porphyrin-quinone systems have been determined. Based on these data, fluorescence quenching as well as time-resolved fluorescence lifetime measurements are discussed in terms of photoinduced electron transfer to the charge-separated zwitterionic state