Structural and Magnetic Properties of Two Copper(II) Complexes Based on Dinuclear Copper(II) Metallacyclophane

Two new oxamato-bridged copper(II) complexes of formula Na10[{Cu2(mpba)2}2(μ1,1-N3)2]·18H2O (1) and [{Cu2(mpba)2}Cu2(H2O)8]·6H2O (2) [mpba = 1,3-phenylenebis(oxamato-N,N′)] have been synthesized and characterized. X-ray crystallographic studies of complex 1 reveal a metallamacrocycle structure in which two dinuclear copper(II) metallacyclophane anions are linked by two single symmetric azido ligands in an end-on mode at axial–axial positions. These metallamacrocycle units are self-assembled through sodium cations and water molecules, affording an intricate 3D network. Complex 2 consists of 2D brick-wall-like layers assembled from dinuclear metallacyclophane [Cu2(mpba)2]4– anions and copper(II) cations. Magnetic susceptibility measurements of complex 1 in the temperature range 2–300 K show dominating ferromagnetic coupling mediated by the m-phenylenediamide bridge and weak antiferromagnetic interaction transmitted by the azido ligand.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)