Nickel(II) and Cobalt(III) bis(dioxolene) complexes with di(2-pyridyl)imine ligands: Synthesis and magnetic properties

Here the synthesis, the molecular structure and the magnetic properties of four novel six-coordinated bis-dioxolene nickel and cobalt complexes with various di(pyridyl)imines as ancillary N-donor ligands is discussed. Despite the analogous composition the obtained compounds show different charge distribution dependently on the nature of complexing metal. Bis-o-semiquinonato nickel(II) complexes demonstrate the strong ferromagnetic exchange interaction between unpaired electrons of the high-spin nickel ion and anion-radical ligands. Cobalt complex containing naphtyl-substituted ancillary ligand demonstrates the proceeding of solid-state redox-isomeric transformation at temperatures above 220 K.