Kinetics of electrode reduction of the tetrachlorocuprate(II) ion: an example of the concerted EC reaction mechanism

The kinetic parameters of reduction of [CuCl 4] 2− ion in acetonitrile at a conventional glassy carbon electrode and at a Pt micro-electrode (10 or 20 μm), have been determined taking into account the double-layer effect: standard rate constant k 0 S = 2.1 × 10 −4 cm s −1, Gibbs energy of activation...

Full description

Saved in:
Bibliographic Details
Published in:Journal of electroanalytical chemistry (Lausanne, Switzerland) Vol. 398; no. 1; pp. 129 - 134
Main Authors: Maletin, Yurii A., Strizhakova, Natalie G., Kozachkov, Sergey G., Cannon, Roderick D.
Format: Journal Article
Language:English
Published: Amsterdam Elsevier B.V 05-12-1995
Elsevier Science
Subjects:
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The kinetic parameters of reduction of [CuCl 4] 2− ion in acetonitrile at a conventional glassy carbon electrode and at a Pt micro-electrode (10 or 20 μm), have been determined taking into account the double-layer effect: standard rate constant k 0 S = 2.1 × 10 −4 cm s −1, Gibbs energy of activation ΔG∗ = 26 kJ mol −1 , pre-exponential factor A ≈ 10 1 cm s −1 and transfer coefficient α = 0.31. Comparison with previous data on similar reactions suggests that the fast escape of chloride ions from the inner coordination sphere, which follows the electron transfer step, retards an EC reaction. If the two steps of the reaction are prectically inseparable, the barrier top broadens, resulting in a decrease in the frequency factor. A low value of the pre-exponential factor, in spite of a low activation barrier, is the main reason for the slowness of the reaction.
ISSN:1572-6657
1873-2569
DOI:10.1016/0022-0728(95)04238-0