@misc{oai:repo.qst.go.jp:00070381,
 author = {Nakanishi, Ikuo and Ohkubo, Kei and Kawashima, Tomonori and Inami, Keiko and Matsumoto, Kenichiro and Mochizuki, Masataka and Fukuhara, Kiyoshi and Okuda, Haruhiro and Ikota, Nobuo and Fukuzumi, Shunichi and Ozawa, Toshihiko and Anzai, Kazunori and 中西 郁夫 and 川島 知憲 and 松本 謙一郎},
 month = {Dec},
 note = {We have recently reported that phenolate anions derived from phenolic antioxidants, such as (+)-catechin and 2,2,5,7,8-pentamethylchroman-6-ol (1H), a vitamin E model, in the presence of a base can act as an electron donor to molecular oxygen to produce superoxide anion, which is one of reactive oxygen species.  However, the detailed redox properties of the phenolate anions have yet to be clarified.  In this study, we report the electron-transfer oxidation reactivities of the phenolate anion (1-) derived from 1H with a series of p-benzoquinone derivatives in acetonitrile (MeCN).
The addition of p-benzoquinone to a deaerated MeCN solution of 1-, which was generated from 1H in the presence of Bu4NOMe, resulted in the facile formation of the corresponding phenoxyl radical.  The rate of electron transfer from 1- to p-benzoquinone was too fast to be determined directly by the stopped-flow technique.  On the other hand, the second-order rate constants for electron transfer from 1- to methyl-p-benzoquinone, 2,6-dimethyl-p-benzoquinone, and tetramethyl-p-benzoquinone were determined as 2500, 220, and 3.7 M-1 s-1, respectively, by monitoring the spectral change observed during the reaction.  The deprotonation of the phenolic OH group in 1H resulted in a largely negative shift of the one-electron oxidation potential, enabling 1- to act as a very strong electron donor., The 2010 International Chemical Congress of Pacific Basin Societies (PACIFICHEM 2010)},
 title = {Electron-Transfer Oxidation of the Phenolate Anion Derived from a Vitamin E Model},
 year = {2010}
}