Synthesis and characterization of a novel tetranuclear nickel(II) complex:[Ni-4(mu-OH)(2)(mu-dppn)(4)( mu-H2O)(2)](C1) (ClO4)(5) center dot 9H(2)O (dppn=3, 6-bis(2-pyridyl)pyridazine)

A novel tetranuclear compound [Ni-4(mu -OH)(2)(mu -dppn)(4)(mu -H2O)(2)](Cl )(ClO4)(5) . 9H(2)O (1) (dppn = 3,6-bis(2-pyridyl)pyridazine) has been synt hesized for the first time and structurally characterized. The pair of nick el atoms that are connected by the (mu -dppn) ligand are joined through the hydroxy group and water molecule bridges to form the tetranuclear core. Wi thin this tetranuclear unit, one nickel atom is six-coordinate with distort ed octahedral geometry and an N4O2 donor set from two equivalent dppn ligan ds and two oxygens of the bridging hydroxy and water molecule. Electronic s pectra and magnetic moment of the complex also reveal a high-spin octahedra l geometry. (C) 2001 Elsevier Science B.V, All rights reserved.