
%0 Journal Article
%A Benari, MD 
%A Hefter, GT 
%T Electrochemical Characteristics of the Copper(II)-Copper(I) Redox Couple in Dimethyl Sulfoxide Solutions
%J Australian Journal of Chemistry
%D 1990/11/01
%V 43
%N 11
%P 1791-1801
%K 
%R https://doi.org/10.1071/CH9901791
%U https://www.publish.csiro.au/paper/CH9901791 
%X A study of the electrochemical characteristics of the copper(II)/copper(I) redox couple has been made in chloride and bromide media in dimethyl sulfoxide (Me2SO) and their aqueous analogues. The formal potentials of the CuII/CuI couple in the Me2SO media are approximately 0.15 V less positive than in their aqueous counterparts probably due to a combination of solvation and complexation effects. Diffusion coefficients for both CuI and CuII are 5-10 times lower in Me2SO than in H2O as a result of the higher viscosity of Me2SO solutions. Heterogeneous electron-transfer rate constants for the CuII/CuI system on platinum are also an order of magnitude smaller than in aqueous solution. In general the electrochemical characteristics of the CuII/CuI system parallel those reported elsewhere for the FeIII/FeII couple. However, a detailed investigation of the CuII/CuI system by cyclic voltammetry indicates that the overall electrode process is complex, probably involving a quasi-reversible electron-transfer step coupled to a rate-determining loss of Cl - from CuII. 
