Water-induced disproportionation of superoxide ion in aprotic solvents
Water-induced disproportionation of superoxide ion in aprotic solvents
复制标题
DOI：
10.1021/jp9625523
复制
发表时间：
1996-12-19
影响因子：
--
通讯作者：
Ohsaka, T
中科院分区：
文献类型：
--
作者：
Che, Y;Tsushima, M;Ohsaka, T
用紫外-可见光谱研究了在乙腈、二甲基甲酰胺和二甲基亚砜介质中，不同浓度的水作为布朗斯台德酸时，电产生的超氧阴离子（O-2（-））的水诱导反硝化作用。作为O-2（-）和水浓度以及测量时间的函数的动力学分析表明，在这些介质中，水对O-2（-）的反硝化遵循共同的机理：O-2（-）+ H2O可逆箭头HO 2。+ OH-（k（1），k（-1））HO2. + O-2（-）--> HO2- + O-2（k（2））（HO2.，过氧化氢自由基; HO 2-，过氧化氢阴离子）。根据O-2（-）和H_2O的溶剂化作用以及H_2O在不同非质子溶剂中的有效酸度，讨论了动力学参数（k（1）/k（-1））、k（2）、k（1）和k（-1）/k（2）的溶剂依赖性。
The water-induced disproportionation of the electrogenerated superoxide ion (O-2(-)) in acetonitrile, dimethylformamide, and dimethyl sulfoxide media containing various concentrations of water as a Bronsted acid has been examined by UV-vis spectroscopy. Analysis of the kinetics as a function of O-2(-) and water concentrations and of the measurement time demonstrated that the disproportionation of O-2(-) by water in these media obeys a common mechanism: O-2(-) + H2O reversible arrow HO2. + OH- (k(1), k(-1)) HO2. + O-2(-) --> HO2- + O-2 (k(2)) (HO2., hydroperoxyl radical; HO2-, hydrogen peroxide anion). The solvent dependence of the obtained kinetic parameters of (k(1)/k(-1))k(2), k(1) and k(-1)/k(2) is discussed in terms of the solvation of O-2(-) and H2O as well as the effective acidities of H2O in different aprotic solvents.