Experimental

R factor = 0.033; wR factor = 0.099; data-to-parameter ratio = 17.6. The asymmetric unit of the title mononuclear CuII complex, [Cu(C7H4FO2)2(C10H14N2O)2(H2O)2], contains one-half of the molecule. The CuII ion is located on an inversion centre, and is coordinated by two N atoms from two diethyl-nicotinamide ligands, two O atoms from two 4-fluorobenzoate (PFB) ligands and two water molecules in a distorted octahedral geometry. In the PFB ligand, the carboxylate group is twisted at an angle of 2.10 (14) from the attached benzene ring. In the crystal structure, intermolecular O— H O hydrogen bonds link molecules related by translation along the a axis into chains. Weak intermolecular C—H O hydrogen bonds and – interactions between the pyridine rings of neighbouring molecules [centroid-to-centroid distance = 3.571 (2) Å] further consolidate the crystal packing. Related literature For background to niacin, see: Krishnamachari (1974). For infomation on the nicotinic acid derivative N,N-diethyl-nicotinamide, see: Bigoli et al. (1972). For related structures