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TEMPERATURE DEPENDENCE OF PHOTOSENSITIZED ELECTRON TRANSPORT ACROSS LIPID VESICLE WALLS
Author(s) -
Mettee Howard D.,
Ford William E.,
Sakai Tetsuya,
Calvin Maelvin
Publication year - 1984
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.1751-1097.1984.tb03909.x
Subject(s) - arrhenius equation , activation energy , quenching (fluorescence) , chemistry , quantum yield , photochemistry , arrhenius plot , vesicle , atmospheric temperature range , photosensitizer , fluorescence , electron transport chain , electron , ruthenium , analytical chemistry (journal) , catalysis , thermodynamics , membrane , organic chemistry , physics , biochemistry , quantum mechanics
— An overall Arrhenius activation energy of 117 plusmn; 19 kJ/mol (28.0 plusmn; 4.5 kcal/mol) has been measured for photosensitized electron transport across phospholipid vesicle walls in the temperature range 18–38°C. A dynamic model for the overall process is proposed which accounts for the parabolic growth curves of the kinetically probed species, heptyl viologen radical. The temperature dependence of the initial quantum yield derived from these curves, and of fluorescence quenching behavior of the ruthenium tris‐bipyridyl photosensitizer, is used to estimate an activation energy of 67 plusmn; 21 kJ/mol(16 plusmn; 5 kcal/mol) for the electron transport step itself. The activation energy for the co‐transport of charge compensating ions is estimated to contribute no more than 4.6 kJ/mol to this energy.