Catena-Poly[[diaquabis(4-formylbenzoato-κO 1)copper(II)]- μ-pyrazine-κ2 N:N′]

Abstract

In the title polymeric compound, [Cu(C8H5O 3)2(C4H4N2)(H2O) 2]n , the CuII atom is located on a twofold rotation axis and has a slightly distorted octahedral coordination sphere. In the equatorial plane, it is coordinated by two carboxylate O atoms of two symmetry-related monodentate formylbenzoate anions and by two N atoms of the bridging pyrazine ligand, which is bisected by the twofold rotation axis. The axial positions are occupied by two O atoms of the coordinating water molecules. In the formylbenzoate anion, the carboxylate group is twisted away from the attached benzene ring by 6.2(2)°, while the benzene and pyrazine rings are oriented at a dihedral angle of 68.91(8)°. The pyrazine ligands bridge the Cu II cations, forming polymeric chains running along the b-axis direction. Strong intramolecular O-H⋯O hydrogen bonds link the water molecules to the carboxylate O atoms. In the crystal, O-Hwater⋯Owater hydrogen bonds link adjacent chains into layers parallel to the bc plane. The layers are linked via C-Hpyrazine⋯Oformyl hydrogen bonds, forming a three-dimensional network. There are also weak C-H⋯π interactions present.