Photoelectron Transport Across Phospholipid Liposomes Pigmented by Anthracene and Naphthalene Derivatives

摘要

In order to investigate effective solar energy conversion system, the light-induced electron transfer reactions have been examined across single-lamellar liposomes incorporated organic photosensitizers such as anthracene and naphthalene derivatives. We have observed photosensitized reduction of methyl viologen (1,1`-dimethyl-4,4`-bipyridinium2+) dissolved in the exterior aqueous phase of the pigmented phospholipid liposomes when EDTA, as electron donor, is dissolved in the enclosed aqueous phase of the liposomes. The anthroyl stearic acid incorporated in the hydrophobic bilayer of liposomes leads to much less quantum yield for the photosensitized reduction of MV2+ than the anthracene carboxylate incorporated in the outer hydrophilic layer. However, モ-carotene with anthroyl stearic acid incorporated into the bilayer enhances the quantum yield significantly (フ = 0.2-0.3), preventing the reverse reaction of electron transfer (MV·+ ℃ MV2+) so that it might be useful for solar energy conversion into chemical energy. A naphthalene derivative, octadecyl naphthylamine sulfonic acid incorporated into the outer layer of liposomes results in less efficiency of MV2+ reduction than anthroyl stearic acid. These results have been also tested with respect to lipid components of liposomes.