Synthesis, crystal structure and magnetic properties of a polynuclear Cu(II) complex: catena-poly-[aqua(di-2-pyridylamine)copper(II)([mu-formato-O,O ')nitrate]

摘要

The synthesis, X-ray structure, spectroscopic and magnetic properties of a zig-zag formato-bridged chain complex with the formula [Cu(dpyam)(mu-O2CH)(OH2)](n)(NO3)(n) (1) (in which dpyam = di-2-pyridylamine) is described. The geometry of the copper(H) ion is distorted square pyramidal with a basal plane consisting of two nitrogen atoms of the dpyam ligand (Cu-N distances 1.987(3) and 2.010(3) angstrom) and two oxygen atoms of two different formato ligands (Cu-O distances 1.974(2) and 1.975(2) angstrom). A coordinated water molecule occupies the axial position at a distance of 2.222(3) angstrom. The copper atoms are bridged unsymmetrically by a formato anion in a syn-anti arrangement, resulting in a polymeric zig-zag chain structure. The magnetic susceptibility measurements (5-280 K) agree with a very weak ferromagnetic chain interaction between the Cu. centres with a J value of 0.75 cm(-1). (c) 2005 Elsevier B.V. All rights reserved.