Hydrothermal synthesis and characterization of a binuclear complex and a coordination polymer of copper(II)

Abstract

Two new copper complexes [(bipy)(pydc)Cu(µ-OCO-pydc)Cu(bipy)(H₂O)].3.5H­₂O (1) and {[(µ₂-C₂O₄)(2,2'-bipy)Cu].2H₂O}_n (2) (pydcH₂ = pyridine-2,6-dicarboxylilic acid, bipy = 2,2'-bipyridine) have been hydrothermally synthesized. Both complexes were characterized by IR spectroscopy, elemental analysis and single crystal X-ray diffraction studies. Complex 1 consists of two independent neutral molecules. In every moiety, metal ion center is in a distorted octahedral geometry. Coordination polymer (2) has been prepared from the reaction of bis-(cyclohexanone)-oxal-dihydrazone,2,2'-bipyridine and Cu(NO₃)₂ in basic solution and under hydrothermal condition. The results showed that the bis-(cyclohexanone)-oxal-dihydrazone was converted to oxalate ion under heating and basic pH. Each metal ion center in 2 is in a distorted octahedral geometry and is coordinated by four oxygen atoms of two bridged oxalate ions and two nitrogen atoms of 2,2'-bipyridine molecules. In the crystal structure of 2, some H-bonds and π-π interaction cause formation of a 3D network.

KEY WORDS: Hydrothermal synthesis, Cu complex, Coordination polymer, Crystal structure

Bull. Chem. Soc. Ethiop. 2010, 24(3), 401-409.