Reduction of chlorothallium(III) complexes by arsenic(III)

Abstract

The oxidation of arsenic(III) by thallium(III) in perchloric acid solution is inhibited by chloride ions. The reactivity of various chlorothallium(III) species is in the order Tl³⁺ > TlCl²⁺ > TlCl₂⁺ > TlCl₃ > TlCl₄^-. The rate decreases by increasing the hydrogen ion concentration and ionic strength. The redox process occurs by intermediate formation of a complex of thallium(III) and arsenic(III). The rate constant for the reaction between Tl³⁺ and arsenic(III) calculated from the data of the present investigation compared well with that of the reaction1 in the absence of chloride ions.