MECHANISM OF SUPEROXIDE ION DISPROPORTIONATION IN APROTIC-SOLVENTS
MECHANISM OF SUPEROXIDE ION DISPROPORTIONATION IN APROTIC-SOLVENTS
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DOI：
10.1021/ja00246a040
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发表时间：
1987-06-10
影响因子：
15
通讯作者：
SAVEANT, JM
中科院分区：
文献类型：
--
作者：
ANDRIEUX, CP;HAPIOT, P;SAVEANT, JM
用双电位阶跃计时电流法研究了二甲基亚砜中氧的电化学还原与酸的关系。动力学分析作为一个功能的分子氧和酸的浓度和测量时间在一系列的酸涉及五酚和硝基甲烷允许determinationof反应机理和特征速率常数。由初始超氧阴离子自由基O2+中和产生的H02+自由基经历O2+自身的电子转移还原，而不是从溶剂中提取氢原子或与另一H02+自由基交换H原子，这是普遍接受的机制。在二甲基甲酰胺中的机理似乎是相同的，这表明超氧离子在非质子有机溶剂和水中的还原遵循相同的反应途径，鉴于其在自然和工业过程中的重要性，分子氧的还原一直是大量研究的对象。这方面的大多数电化学研究都是在水中进行的。1双氧的还原然后导致过氧化氢或水，
The electrochemical reduction of dioxygen in dimethyl sulfoxide is investigated as a function of the addition of acids by means of double potential step chronoamperometry. Analysis of the kinetics as a function of dioxygen and acid concentrations and of the measurement time in a series of acids involving fivephenols and nitromethane allowed the determinationof the reaction mechanism and of the characteristic rate constants. The H02" radical resulting from the neutralizationof the initial superoxide anion radical, 02*~, undergoes an electron-transfer reduction by 02 ‘“itself rather than abstracting a hydrogen atom from thesolvent or exchanging an H atom with another H02" radical, a commonly accepted mechanism. The mechanism appears to be the same in dimethylformamide, pointing to the conclusion that disproportionationof superoxide ions follows the same reaction pathway in aprotic organic solvents and in water.In view of its significance in natural and industrial processes, the reduction of dioxygen has been the object of a very large number of studies. Most of the electrochemical investigations in this connection have been carried out in water. 1 Thereduction of dioxygenthen leads to hydrogen peroxide or water, which