Di-2-pyridyl ketone in lanthanide(III) chemistry: Mononuclear and dinuclear erbium(III) complexes

The reaction between Er(NCS)3 and di-2-pyridyl ketone in alcohols gives mononuclear and dinuclear isothiocyanate complexes depending on the OH− concentration in the reaction system. In the mononuclear complexes the neutral hemiacetal form of the ligand adopts the coordination mode A, while in the dinuclear complex the hemiacetal form of the ligand is anionic bridging two ErIII atoms (coordination mode B).