title: Spectra and structure of alpha-tocopherol radicals produced in anoxic media.
abstract: Electron spin resonance and flash photolysis studies have been combined to determine, amid conflicting reports from radiolysis studies, the spectrum for the phenoxyl radical of alpha-tocopherol. Triplet state ketones were used to abstract the alpha-tocopherol phenolic hydrogen in order to obtain both the transient ESR spectrum and optical spectrum. Analysis of the ESR data yields g = 2.00469, a(H, 5-CCH3) = 6.04G, a(H,7-CCH3) = 4.51G, a(H, CH2) = 1.38G, a(H', CH2) = 1.49G, and a(H,8-CCH3) = 0.89G. The g factor shows large spin population on oxygen in this radical and demonstrates conclusively involvement of the phenoxyl radical. Both spectra were in agreement with those produced by radiolysis of alpha-tocopherol in N2 saturated EtOH. While the spectral characteristics of the phenoxyl radical now appear to be clarified, uncertainties remain concerning optical spectra for radiolysis of alpha-tocopherol in air- and oxygen-containing systems.
authors.affiliation: Laboratoire de Chimie-Physique, Université René Descartes, Paris, France.
authors.forename: D
authors.initials: D
authors.lastname: Jore
authors.forename: C
authors.initials: C
authors.lastname: Ferradini
authors.forename: K P
authors.initials: KP
authors.lastname: Madden
authors.forename: L K
authors.initials: LK
authors.lastname: Patterson
mesh_terms: D000693:Anaerobiosis; D004578:Electron Spin Resonance Spectroscopy; D005609:Free Radicals; D007700:Kinetics; D007834:Lasers; D010782:Photolysis; D014810:Vitamin E / Q000737:chemistry* / Q000528:radiation effects
chemical_list: D005609:Free Radicals; D014810:Vitamin E