Equilibrium and structural studies of copper and nickel complexes with a pentadentate ligand providing amide, amine and pyridyl nitrogen donors. Crystal structure of the dinuclear nickel(II) complex

The reaction of M2+ ion with pycdien, a potentially pentadentate bis(picolinamide) ligand leads to copper(II) compounds with the coordination number four or five, whereas nickel gives octahedral complexes.