Photophysical properties of porphyrins, phthalocyanines, and benzochlorins

This work examines the photophysical properties of a series of porphyrin, phthalocyanine, and benzochlorin derivatives. The porphyrin group includes tetraphenylporphyrin, divinylporphyrin ether, dihematoporphyrin ether, the trivinylporphyrin ether, and the trihematoporphyrin ether. The phthalocyanine group includes phthalocyanine tetrasulfonate, chloroaluminum phthalocyanine tetrasulfonate, zinc phthalocyanine tetrasulfonate, and aluminum naphthalocyanine tetrasulfonate. The chlorins include octaethylbenzochlorin, zinc octaethylbenzochlorin, octaethylbenzochlorin sulfonic acid, and zinc octaethylbenzochlorin sulfonic acid. Ethyl etiopurpurin is also studied. The UV-Vis and fluorescence emission spectra, fluorescence quantum yields, fluorescence rate constants, radiative and singlet state lifetimes are compared for the series of compounds. Results indicate that while the octaethylbenzochlorin and phthalocyanine photosensitizers present a similar photophysical profile, this profile is very different from that observed for the porphyrin photosensitizers. (C) 1998 Elsevier Science S.A. All rights reserved.