Desolvation step preceding electroreduction and the electrochemical reactions of the Ni(II)/Ni(Hg) system in dimethylformamide (DMF) and its mixtures with water

✍ Scribed by Laura Janiszewska; Zbigniew Galus

• Publisher: Elsevier Science
• Year: 1982
• Tongue: English
• Weight: 775 KB
• Volume: 27
• Category: Article
• ISSN: 0013-4686
• DOI: 10.1016/0013-4686(82)80177-1

✦ Synopsis

The kinetics of the electrode reaction of the Ni(Il)/Ni(Hg) system in DMF and its mixtures with water at different concentrations of several background electrolytes has been studied. Similarly to aqueous solutions, at higher background electrolyte concentrations the charge transfer step is preceded by a chemical reaction. It was deduced that this preceding reaction is due to slow dissociaiation of the solvent molecule in the Shprocess. The change ofa solvent from water to 70~01. % of DMF decreases the standard rateconstant (kd for about one order of magnitude. At larger DMF content k, is virtually independent of the solvent composition. The change of k, with the DMF content was explained by assuming the resolvation of Ni(lI) ions at the electrode surface in proportion to the surface coverage of the electrode molecules of both solvents.