Oxidation of substituted iron carbonyl complexes in acetonitrile, acetone, and dichloromethane at mercury and platinum electrodes

Article abstract of DOI:10.1021/ic50217a024

The oxidative electrochemistry of the substituted iron carbonyl complexes Fe(CO)₄L and Fe(CO)₃L₂, where L is a monodentate tertiary phosphine, arsine, or stibine ligand, has been studied in acetone, dichloromethane, and acetonitrile at both Hg and Pt electrodes. At platinum electrodes, for L = AsPh₃ or SbPh₃ the initially generated 17-electron cations [Fe(CO)₄L]⁺ and [Fe(CO)₃L₂]⁺ are unstable in all solvents while with phosphorus ligands the species [Fe(CO)₃(PPh₃)₂]⁺ has some stability in dichloromethane. Reactions leading to decomposition are considered. In marked contrast, at mercury electrodes, the cations appear to be substantially more stable than at platinum, and chemically reversible behavior can be observed where the response is completely irreversible at platinum. The data are explained in terms of a chemically modified pathway at mercury electrodes giving rise to mercury stabilized cations.