Influence of thallium(I) and thallium(III) on parameters of oscillating chemical reaction in a bromate-cerium(III,IV)-malonic acid-sulfuric acid system

The influence of thallium(I) and thallium(III) on the parameters of the Belousov-Zhabotinskii oscillating chemical reaction in the bromate-cerium(III, IV)-malonic acid-sulfuric acid system was studied. As a result of the addition of thallium(I) and thallium(III), the oscillation parameters change in the same way, which cannot be explained by the complexation of these ions with the bromide only. It was found that during the oscillating reaction, thallium(I) can be oxidized by bromine-containing compounds and thallium(III) reduced by the transformation products of malonic and bromomalonic acids. A scheme of action of a thallium(III)/thallium(I) two-electron redox pair in the oscillating chemical reaction studied has been proposed.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 23, No. 1, pp. 106–111, January–February, 1987.