Synthesis and Crystal Structure of Supramolecular Copper(II) Dimer with Asymmetric Salamo-Type Ligand

A novel Cu(II) dimer, [CuL](2), has been synthesized via the complexation of Cu(II) acetate monohydrate with 6-ethoxy-4',6'-dibromo2,2'-[ethylenedioxybis(nitrilo-methylidyne)] diphenol (H2L) in methanol/acetone mixed solution and characterized structurally by X-ray diffraction method. X-ray crystallographic analysis reveals that the Cu: L is 2: 2 in one dimer molecule and the coordination numbers of copper(II) atoms are four and five, resulting in slightly distorted square-planar and square-pyramidal geometries, respectively. With the help of intermolecular C1-H1A center dot center dot center dot O9, C19-H19B center dot center dot center dot O4, C20-H20B center dot center dot center dot O5 and C25-H25 center dot center dot center dot O6 hydrogen-bonding interactions, a self-assembled 2D-layer supramolecular structure is formed.