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氮氧自由基在电极上可得到电子而被还原,但关于哌啶氮氧自由基在水溶液中的电极还原反应,仅Neiman等用经典极谱法考察过其半波还原电位与介质pH的关系,认为自由基被还原为相应羟胺,质子参与电极反应,但未能确定质子化过程是先于还是后于电子转移过程。氮氧自由基在水溶液中可氧化谷胱甘肽、半胱氨酸,反应产物分布强烈受介质pH影响。氮氧自由基氧化维生素C的速率随介质pH改变而变化。已经证明,这些反应均经过单电子转移氧化还原反应机理,氮氧自由基均被还原为羟胺。因此,用电化学方法研究质子在氮氧自由基单电子还原过程中的作用,对于进一步阐明氮氧自由基与上述生物分子的电子转移反应机理无疑有一定实际意义。
Nitroxide radicals can be obtained on the electrode to be reduced by electrons. However, only Neiman et al. Have investigated the relationship between the half-wave reduction potential and the pH of the medium by classical polarography with respect to the electrode reduction reaction of piperidine nitroxide in aqueous solution , That free radicals are reduced to the corresponding hydroxylamine, protons involved in the electrode reaction, but failed to determine whether the protonation process before or after the electron transfer process. Nitroxide oxidizes glutathione and cysteine in aqueous solution. The reaction product distribution is strongly influenced by the medium pH. The rate of oxidation of vitamin C by nitroxides varies with the pH of the medium. It has been shown that these reactions undergo a single electron transfer redox reaction mechanism, and both nitroxide radicals are reduced to hydroxylamine. Therefore, using electrochemical methods to study the role of protons in the mono-electron reduction of nitroxides will undoubtedly have some practical significance to further elucidate the electron transfer reaction mechanism between nitroxides and the above-mentioned biomolecules.