Investigation of electron-transfer kinetics for bis(benzene) chromium(1+/0) redox couple in acetonitrile/dichloromethane binary mixtures at 298.15 K

The oxidation of bis(benzene) chromium(0) (Bz2Cr) to bis(benzene) chromium(1+) (Bz2Cr+) in acetonitrile (ACN), dichloromethane (DCM), and acetonitrile (ACN)/dichloromethane (DCM) binary mixtures with n-tetrabutylammonium hexafluorophosphate (TBAPF6) as background electrolyte has been studied using the method of cyclic voltammetry at a temperature of 298.15 K. The diffusion coefficients (D) have been calculated using the Randles–Sevcik equation. The heterogeneous electron transfer rate constants (ks) have been evaluated employing the electrochemical rate equation proposed by Nicholson. The one-electron oxidation of Bz2Cr to produce Bz2Cr+ was found to be either reversible or quasi-reversible and diffusion controlled in the investigated solvent media. The effect of the physical and chemical properties of the solvent medium on the electrochemical behavior of the Bz2Cr+/Bz2Cr couple has been examined.

Graphical abstractThe oxidation of bis(benzene) chromium(0) to bis(benzene) chromium(1+) in acetonitrile/dichloromethane binary mixtures was investigated by means of cyclic voltammetry. The heterogeneous electron-transfer rate constants were evaluated. The one-electron oxidation process was found to be either reversible or quasi-reversible and diffusion controlled in the investigated solvent media.Figure optionsDownload full-size imageDownload as PowerPoint slide