Dinuclear metal complexes composed of peptide chains: Solvent-induced switching and inversion of the metal-centered chirality

The peptide-linked bisbipyridine separated by a rigid or flexible spacer formed a dinuclear FeII complex, which showed a unique solvent-induced inversion and on-off switching of the metal-centered chirality depending on the spacer, resulting from the supramolecular structural change between a dinuclear helicate and a mono peptide ligand-bridged dinuclear Fe-II complex. The rigid and flexible spacer groups connecting the peptide residues are responsible for these unique structural and chiroptical properties occurring at the metal center.