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Determination of Fluorescence Yields, Singlet Lifetimes and Singlet Oxygen Yields of Water‐Insoluble Porphyrins and Metalloporphyrins in Organic Solvents and in Aqueous Media
Author(s) -
Figueiredo Telmo L. C.,
Johnstone Robert A. W.,
Sørensen Alexandra M. P. SantAna,
Burget Dominique,
Jacques Patrice
Publication year - 1999
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1111/j.1751-1097.1999.tb03322.x
Subject(s) - singlet oxygen , chemistry , photochemistry , quantum yield , aqueous solution , porphyrin , molecule , singlet state , fluorescence , reaction rate constant , oxygen , toluene , polymer , organic chemistry , excited state , kinetics , physics , quantum mechanics , nuclear physics
— Fluorescence quantum yields and singlet lifetimes for a wide range of hydrophilic to hydrophobic porphyrins and metalloporphyrins have been determined in toluene, methanol or acetone. Photosensitized singlet oxygen yields have been determined in the same solvents. For some porphyrins, the same quantities were determined in an aqueous medium, through use of an amphiphilic polymer to solubilize the porphyrin sensitizer and target molecule, 1, 3‐diphenylisobenzofuran. Because rate constants for the deactivation of singlet oxygen ( k d ) and for its reaction with a target molecule (k a ) are unknown in such aqueous polymer systems, a new method was developed for evaluating yields of singlet oxygen formation that also provides a value for the ratio k d /k a . A variation observed in quantum yield of singlet oxygen production for the aqueous polymer system with variation in initial concentration of the target molecule is discussed.