Crystal structure of the mixed-ligand complex of Co(II) with succinic acid and pyridine

A new mixed-ligand complex {[Со(С4Н4О4)2Ру]2H2O}n was synthesized via the interaction of equimolar amounts of cobalt nitrate and sodium succinate in the presence of pyridine at pH 5.5–6.0. The complex was investigated by X-ray structure analysis, elemental analysis, UV/VIS and IR spectroscopies, and differential thermal analysis. The complex is a one-dimensional coordination polymer and crystallizes in the orthorhombic space group Pbca with unit cell parameters a=11.8945 Å, b=8.9064 Å, c=15.1116 Å, ===900. The atom of cobalt has a slightly distorted octahedral N2O4 environment and forms Co–N bonds with two molecules of pyridine and Co–O bonds with the carboxyl groups of two symmetric succinic acid molecules. The coordination number Co(II) is supplemented up to 6 by two water molecules, which are located in the axial plane of the coordination polyhedron. Due to the monodentate coordination of two symmetrically independent carboxylate oxygen atoms of one succinic acid molecule, one-dimensional coordination polymer chains are formed. Polymer chains in the crystal are united by intermolecular hydrogen bonds, which leads to the formation of layers packed in the crystal parallel to the (001) plane. Hirschfeld surface analysis and two-dimensional fingerprint plots were used to analyze the intermolecular interactions present in the crystal.