Iron–xanthate complexes [Fe(CO)2(η-C5R5){SC(S)OEt}] and [Fe(CO)(η-C5R5)(S2COEt)](R = H or Me). Synthesis and electrochemistry

Abstract

Xanthate complexes of the type [Fe(CO)₂(η-C₅R₅){SC(S)OEt}][R = H (1) or Me (2)] can be conveniently prepared by reaction between [{Fe(CO)₂(η-C₅R₅)}] and [SC(S)OEt]₂ in cyclohexane. U.v. photolysis of (1) and (2) causes decarbonylation and affords the chelate complexes [Fe(CO)(η-C₅R₅)(S₂COEt)][R = H (3) or Me (4)]. The electrochemical behaviour of these complexes has been studied both in acetonitrile and dichloromethane using cyclic voltammetry and coulometry. The monocarbonyl complexes (3) and (4) in dichloromethane exhibit a reversible oxidation–reduction process. In acetonitrile the oxidation reaction is accompanied by the co-ordination of solvent. The multicyclic voltammograms of the dicarbonyl complexes (1) and (2), in both solvents, reveal that the oxidation is followed by elimination of one molecule of carbon monoxide from iron, affording the corresponding chelate complexes (3) and (4).