A tetracopper(II) complex with N,N′-bis(picolinoyl)hydrazine

Abstract

Synthesis, physical properties and X-ray structure of a hydrated tetranuclear copper(II) complex [Cu4(μ-diph)2(μ- H2O)2(O2CCH3)4(H 2O)2]·4H2O with N,N′- bis(picolinoyl)hydrazine (H2diph) are reported. The centrosymmetric complex has two types of copper(II) centres with distorted square-pyramidal N2O3 coordination spheres. The dinucleating trans planar diph2- ligands are parallel to each other and act as N 2O-donor to one metal centre and N2-donor to the other metal centre. The complex has a rectangular {Cu4(μ-N-N) 2(μ-OH2)2} core with Cu·· ·Cu distances as 4.834(1) and 3.762(1) . Solid state as well as solution electronic spectra show several transitions in the wavelength range 700-280 nm. The room temperature (298 K) solid state magnetic moment is 3.55 μB. The powder EPR spectra at 298 and 130 K are very similar and axial (g∥ = 2.25 and g⊥ = 2.08) in character. © 2011 Elsevier B.V. All rights reserved.