Electrochemical generation and stability of butadiene(tricarbonyl)iron anion in the presence of electrophiles and under CO pressure1

Abstract

In tetrahydrofuran at –20 °C cyclic voltammetry of [Fe(CO)₃(η-C₄H₆)] shows to one-electron reduction steps whereas at room temperature only the first is observed; electrolysis leads to the generation of the corresponding anion, in which one of the C–C double bonds is no longer co-ordinated to the iron atom, this anion reacting with H⁺ or halides leading to the πallyl complexes, and under CO pressure, the butadiene ligand is deco-ordinated with formation of [Fe₂(CO)₈]^2–.