Bisulfite-driven autocatalysis in the bromate-thiosulfate reaction in a slightly acidic medium

Zhen Wang, Qingyu Gao, Changwei Pan, Yuemin Zhao, Attila K. Horváth

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10 Citations (Scopus)

Abstract

The thiosulfate-bromate reaction has been studied by high-performance liquid chromatography, monitoring the concentrations of thiosulfate and tetrathionate simultaneously. It is found that concentration-time curves of both species display a sigmoidal shape in a slightly acidic, well-buffered medium. Unlike the previously reported complex reaction systems involving bromate, this nonlinear dynamical behavior originates from neither proton nor bromine(III) autocatalysis under our experimental conditions. We demonstrated that sulfur(IV) species significantly accelerates the reaction; therefore, it acts as an autocatalyst. To the best of our knowledge, no reaction system has yet been reported among the pH-driven oxysulfur-oxyhalogen systems, where sulfur(IV) has such a remarkable role. On the basis of the simultaneous evaluation of [S 2O 3 2-] and [S 4O 6 2-] time series, an eight-step kinetic model is proposed to account for the experimental observations. The model employed here may serve as a solid starting point to extend it for other oxysulfur-oxyhalogen systems where such a seemingly general phenomenon may become observable.

Original languageEnglish
Pages (from-to)12062-12064
Number of pages3
JournalInorganic Chemistry
Volume51
Issue number22
DOIs
Publication statusPublished - Nov 19 2012

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ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Inorganic Chemistry

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