The asymmetric unit of the title polymeric compound, [Cu(C8H4NO2)2(C10H14N2O)(H2O)] n , contains one Cu(II) atom, one coordinating water mol-ecule, two 4-cyano-benzoate (CB) ligands and one coordinating N,N-di-ethyl-nicotinamide (DENA) mol-ecule. The DENA ligand acts as a bis-monodentate ligand, while the CB anions are monodentate. Two O atoms of the CB ligands, one O atom of the water mol-ecule and the pyridine N atom of the DENA ligand form a slightly distorted square-planar arrangement around the Cu(II) atom which is completed to a square-pyramidal coordination by the apically placed O atom of the DENA ligand, with a Cu-O distance of 2.4303 (15) Å. In the two CB anions, the carboxyl-ate groups are twisted relative to the attached benzene rings by 2.19 (12) and 3.87 (15)°, while the benzene rings are oriented at a dihedral angle of 5.52 (8)°. The DENA ligands bridge adjacent Cu(2+) ions, forming polymeric coordination chains running along the b axis. In the crystal, strong water-carboxyl-ate O-H⋯O hydrogen bonds link adjacent chains into layers parallel to (10-1) and weak C-H⋯O hydrogen bonds further stabilize the crystal structure. The cyano group C and N atoms of one of the CB ligands are disordered over two sets of sites with equal occupancies.
Keywords: coordination polymers; copper(II) benzoates; crystal structure; nicotinamide ligands.