Electrochemical behaviour of some 3-methylthio-1,2-dithiolium cations in dimethylformamide solution

• Published in: Electrochimica acta Vol. 50; no. 11; pp. 2219 - 2225
• Main Authors: Abasq, Marie-Laurence, Burgot, Jean-Louis, Darchen, André, Saidi, Mokhtar
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.04.2005; Elsevier
• Subjects: Anethole dithiolethione; Chemistry; Cyclic voltammetry; Dimerization; Electrochemistry; Exact sciences and technology; General and physical chemistry; Kinetics and mechanism of reactions; Ring opening; Sulfarlem; Anethole dithiolethione; Cyclic voltammetry; Sulfarlem; Dimerization; Ring opening; Organic solvent; Organic cation; N,N-Dimethylformamide; Reaction mechanism; Electrochemical reaction; Ring cleavage
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2004.10.004

Substituted 3-methylthio-1,2-dithiolium cations were prepared by alkylation of the corresponding 1,2-dithiole-3-thiones. These compounds were easily reduced in DMF at a mercury electrode, following two one-electron waves. Electrolysis, carried out at a mercury pool electrode and followed by an alkylation or an acylation, provided the corresponding alkyl (or acyl) dithioesters and by-products. At a platinum or glassy carbon electrode the reduction was an irreversible process, which was dependent upon the cathode nature. Whatever the electrode, the reduction was a combination of two reactions, a two-electron reduction and a one-electron one involving a dimerization. The electrochemical behaviour of 3-methylthio-1,2-dithiolium cations exhibited many analogies with the cathodic behaviour of the corresponding 1,2-dithiole-3-thiones. Moreover, identical intermediates were implicated in the reduction of 3-methylthio-1,2-dithiolium cations and in the reductive alkylation of 1,2-dithiole-3-thiones.