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Z. Naturforsch. 2014,
69b, 321 – 326
doi:10.5560/ZNB.2014-3309
A Dimeric Copper(II) Complex of Oxalate and Oxamide Dioxime Ligands: Synthesis, Crystal Structure, Thermal Stability, and Magnetic Properties
1 Department of Inorganic Chemistry, University of Yaounde 1, P. O. Box 812, Yaounde, Cameroon
2 Department of Chemistry, University of Buea, P. O. Box 63, Buea, Cameroon
3 Laboratoire Multimatériaux et Interfaces, Université Claude Bernard, Lyon 1, 69622 Villeurbanne Cedex, France
4 Institute for Inorganic Chemistry, RWTH Aachen University, D-52056 Aachen, Germany
Reprint requests to Prof. J. Nenwa. E-mail:
jnenwa@yahoo.fr
Received November 6, 2013 / published online March 17, 2014
The dimeric copper(II) complex [Cu(C2O4)(H2oxado)(H2O)]2 (1), where H2oxado = oxamide dioxime, has been synthesized in water and characterized by elemental and thermal analyses, IR spectroscopy, and single-crystal X-ray diffraction. Complex 1 is composed of two neutral [Cu(C2O4)(H2oxado)(H2O)] entities connected by Cu–O bonds between oxalate oxygen atoms and copper(II) ions, thereby producing a centrosymmetric dimer, with the Cu(II) centers exhibiting a strongly distorted octahedral coordination. Neighboring dimers are hydrogen-bonded through O–H⋯O interactions leading overall to a layer structure. Thermal analyses of complex 1 showed
two significant weight losses corresponding to the coordinated water molecules, followed by the decomposition of the network. Variable-temperature (10–300K) magnetic susceptibility measurements revealed very weak antiferromagnetic interactions (θ =−0.86 K from Curie–Weiss law behavior) within the dinuclear unit.
Key words: Oxalate, Oxamide Dioxime, Cu(II) Complex, Crystal Structure