Hexathio benzene derivatives

The highly substituted aromatic compound hexakis (benzylthio)benzene is oxidized electrochemically. The reaction proceeds in a two-step mechanism via a blue radical cation to a red product. Although only a single peak couple is found in cyclic voltammetry, the two successive electron transfer steps can be distinguished by fractional electrolyses with determination of the open circuit potential. A theoretical analysis of the open circuit potential development with the extent of electrolysis provides values of the two formal potentials. They differ by only 23 mV, resulting in a comproportionation equilibrium constant close to unity.
Cyclic voltammograms of the starting compound can successfully be simulated with this value.

Coworkers in this project:

Kai Ludwig, Gloria M. Quintanilla and Andreas Stauß

Oral presentations:

Bernd Speiser at the

59th ISE Annual Meeting, Sevilla/Spain, Sept. 7-12, 2008, keynote lecture

Publications from this project:

K. Ludwig, M.G. Quintanilla, B. Speiser und A. Stauß, J. Electroanal. Chem. 531, 9 - 18 (2002); Two-Electron-Transfer Redox Systems. Part 6. Two-Electron Oxidation of Hexakis(benzylthio)benzene -- A Study by Electrolysis and Cyclic Voltammetry.

K. Ludwig und B. Speiser, J. Electroanal. Chem. 531, 1 - 8 (2002); Electroanalytical Simulations, Part 17. Calculation of Open Circuit Potentials during Fractional Electrolysis in Two-Electron-Transfer Systems.

B. Speiser, K. Ludwig, A. Stauß und M.G. Quintanilla, Proc. Electrochem. Soc., 2001-14, 69 - 72 (2001); Two-Electron-Transfer Redox Systems. Part 4. Electrochemical Oxidation of Hexa(benzylthio)benzene -- Formation and Reaction of a Radical Cation.