Reduction of oxyiron(V) by sulfite and thiosulfate in aqueous solution.
Reduction of oxyiron(V) by sulfite and thiosulfate in aqueous solution.
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DOI：
10.1021/jp901994x
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发表时间：
2009-07
期刊：
影响因子：
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通讯作者：
V. Sharma;D. Cabelli
中科院分区：
文献类型：
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作者：
V. Sharma;D. Cabelli
在厌氧条件下，采用预混脉冲辐解技术研究了无机硫氧物种（SO（3）（2-）和S_2O（3）（2-））对Fe（V）O（4）（3-）的还原反应。研究了Fe（VI）O（4）（2-）与两种硫自由基的反应。光谱结果表明，硫自由基将Fe（VI）O（4）（2-）还原为Fe（V）O（4）（3-），随后通过双电子还原步骤被氧硫物种还原为Fe（III）。Fe（VI）O（4）（2-）被亚硫酸根和硫代硫酸根（* SO 3-和S4 O（6）（*3-））还原为Fe（V）O（4）（3-）的速率常数分别为（1.9 +/- 0.3）x 10（8）和（7.5 +/- 0.8）x 10（7）M（-1）s（-1）。而Fe（V）O（4）（3-）与SO（3）（2-）和S2 O（3）（2-）离子的反应则相隔一个数量级，与SO（3）（2-）在（3.9 +/- 0.3）× 10（4）M（-1）s（-1）下反应，而S2 O（3）（2-）与Fe（V）在（2.1 +/- 0.1）× 10（3）M（-1）s（-1）下反应，pH 11.4。
The reduction of oxyiron(V), Fe(V)O(4)(3-) by inorganic oxysulfur species (SO(3)(2-) and S2O(3)(2-)) has been studied anaerobically in alkaline medium by using a premix pulse radiolysis technique. Studies on the reactions of Fe(VI)O(4)(2-) with the two sulfur radicals were also carried out. The spectroscopic results demonstrated that sulfur radicals reduced Fe(VI)O(4)(2-) to Fe(V)O(4)(3-) which is subsequently reduced by oxysulfur species by a two-electron reduction step to Fe(III). The rate constants for reduction of Fe(VI)O(4)(2-) to Fe(V)O(4)(3-) by sulfite and thiosulfate radicals (*SO3- and S4O(6)(*3-)) were found to be (1.9 +/- 0.3) x 10(8) and (7.5 +/- 0.8) x 10(7) M(-1) s(-1), respectively. However, the reactions of Fe(V)O(4)(3-) with the SO(3)(2-) and S2O(3)(2-) ions were separated by an order of magnitude, with SO(3)(2-) reacting at (3.9 +/- 0.3) x 10(4) M(-1) s(-1) while S2O(3)(2-) reacted with Fe(V) at (2.1 +/- 0.1) x 10(3) M(-1) s(-1) at pH 11.4.