Electrochemical Study of cis-Dicyanobisethylenediaminechromium(III) Ion and Its Adducts with Hg(II) and Ag(I)

Abstract

Electrochemical properties of [Cr(CN2)(en)2]+ are described. Reactions of this complex with Hg(II) and Ag(I) were studied. Their stoichiometry (1 : 1) was determined using potentiometric and amperometric titration. Different pulse voltammetry (DPV) was applied to identify their products - dinuclear adducts. It was concluded on the bases of DPV experiments that linkage isomerization of bridding cyano ligand occurs in the process of adducts formation. The decomposition (aquation) of these adducts was followed and the influence of H+ and Hg2+ concentration on its rate was measured and discussed. The paper also deals with a spontaneous isomerization of unstable CN linkage isomers Cr(NC)2 and Cr(CN)(CN) to the stable isomer Cr(NC)2.