A CIDEP and fluorescence study of the oxidation of vitamin E: the vitamin E radical cation.
The photochemical and thermal oxidations of vitamin E in trifluoroacetic acid were investigated by the combination of electron spin resonance, chemically induced dynamic electron polarization, and fluorescence techniques. Two independent thermal pathways led to the formation of the vitamin E radical cation in which one of the paths involved the intermediate neutral semiquinone radical. Photo-oxidation, however, did not involve the neutral radicals. The fluorescence spectra of both the neutral and the charged forms of the vitamin E radicals are reported here for the first time. Some model charge transfer reactions involving the vitamin E radical cation were reported.
Depew
M C
MC
Department of Chemistry, Queen's University, Kingston, Ontario, Canada.
Craw
M T
MT
MacCormick
K
K
Wan
J K
JK
D004578:Electron Spin Resonance Spectroscopy / Q000379:methods; D005609:Free Radicals; D010084:Oxidation-Reduction; D010777:Photochemistry; D013050:Spectrometry, Fluorescence / Q000379:methods; D013816:Thermodynamics; D014810:Vitamin E
D005609:Free Radicals; D014810:Vitamin E