重新研究近中性介质中连四硫酸盐-次氯酸反应的动力学和机制。

Revisiting the kinetics and mechanism of the tetrathionate-hypochlorous acid reaction in nearly neutral medium.

机构信息

Department of Inorganic Chemistry, University of Pécs, Ifjúság útja 6., H-7624 Pécs, Hungary.

出版信息

J Phys Chem A. 2009 Dec 17;113(50):13907-12. doi: 10.1021/jp907157w.

PMID:19902956

Abstract

The tetrathionate-hypochlorous acid reaction has been investigated in nearly neutral medium at I = 0.5 M ionic strength and T = 25.0 +/- 0.1 degrees C in dihydrogen-phosphate-hydrogen-phosphate buffer by UV-vis spectrophotometry. In excess of hypochlorous acid, the stoichiometry was found to be S(4)O(6)(2-) + 7HOCl + 3H(2)O --> 4SO(4)(2-) + 7Cl(-) + 13H(+), but in excess of tetrathionate colloidal sulfur precipitates. On the basis of the simultaneous evaluation of the kinetic curves, a nine-step kinetic model with four fitted and five fixed rate coefficients is proposed. Analogous oxidation reactions of tetrathionate are also compared and discussed.

摘要

四硫代硫酸根-次氯酸反应在 I = 0.5 M 离子强度和 T = 25.0 ± 0.1°C 的近中性介质中，通过紫外-可见分光光度法在磷酸二氢盐-氢磷酸盐缓冲溶液中进行了研究。在次氯酸过量的情况下，发现化学计量比为 S(4)O(6)(2-) + 7HOCl + 3H(2)O --> 4SO(4)(2-) + 7Cl(-) + 13H(+)，但过量的四硫代硫酸盐会产生胶体硫沉淀。基于对动力学曲线的同时评估，提出了一个具有四个拟合和五个固定速率系数的九步动力学模型。还比较和讨论了四硫代硫酸盐的类似氧化反应。