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FORMES TRANSITOIRES DES CAROTENOIDES: ETAT TRIPLET ET RADICAL‐CATION
Author(s) -
MATHIS P.,
VERMEGLIO A.
Publication year - 1972
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.1751-1097.1972.tb06235.x
Subject(s) - flash photolysis , chemistry , photochemistry , triplet state , toluidine , protonation , radical ion , absorption (acoustics) , ion , molecule , organic chemistry , materials science , physics , quantum mechanics , reaction rate constant , kinetics , composite material
— Reactions between toluidine blue (a thiazine dye) and carotenoids (β‐carotene and zeaxanthine) were studied by flash photolysis, in ethanolic solutions. Two types of reactions were evidenced:1 a triplet‐triplet energy transfer from the triplet state of monoprotonated toluidine blue to the carotenoid whose triplet state decays rapidly ( t 1/2 = 5μsec). 2 an electron transfer from the carotenoid to the mono‐ and bi‐protonated triplet states of toluidine blue. This produces a radical‐cation of the carotenoid (Car + ) which decays slowly ( t 1/2 ˜ 200 μsec) and has a strong absorption band around 900 nm.