A molecular redox switch via iron translocation in a bicompartmental ligand

Mononuclear complexes of an unsymmetrical bicompartmental ligand containing an iron ion that can occupy either the 'soft nitrogen box' or the 'hard oxygen box' have been synthesized. When the ferric iron is electrochemically reduced or when the ferrous iron is electrochemically oxidized, it hops from one binding site to the other. The process is reversible. During the switching process, the iron ion remains bound to the bridging phenolate ligand and the iron translocation may be regarded as a 'pendular motion'.