Diaquabis(N,N′-diethylnicotinamide-κN 1)bis(4-fluorobenzoato-κO)copper(II)

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 diethylnicotinamide 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 π–π interactions between the pyridine rings of neighbouring molecules [centroid-to-centroid distance = 3.571 (2) Å] further consolidate the crystal packing.

The asymmetric unit of the title mononuclear Cu II complex, [Cu(C 7 H 4 FO 2 ) 2 (C 10 H 14 N 2 O) 2 (H 2 O) 2 ], contains one-half of the molecule. The Cu II ion is located on an inversion centre, and is coordinated by two N atoms from two diethylnicotinamide 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-HÁ Á ÁO hydrogen bonds link molecules related by translation along the a axis into chains. Weak intermolecular C-HÁ Á ÁO hydrogen bonds andinteractions between the pyridine rings of neighbouring molecules [centroid-to-centroid distance = 3.571 (2) Å ] further consolidate the crystal packing.
The asymmetric unit of the title mononuclear Cu II complex contains one-half molecule, the Cu II atom being located on an inversion center. The unit cell of the title compound contains also two N,N-diethylnicotinamide (DENA) ligands, two 4fluorobenzoato (PFB) ligands and two coordinated water molecules. All ligands coordinate the Cu in a monodentate manner.  et al., 1996), [Co(C 6 et al., 2009b) have also been reported.
In the copper(II) complex mentioned above the two benzoate ions coordinate to the Cu II atom as bidentate ligands, while in the other structures all the ligands coordinate in a monodentate manner.

Experimental
The title compound was prepared by the reaction of CuSO 4 .5H 2 O (1.23 g, 5 mmol) in H 2 O (20 ml) and DENA (1.78 g, 10 mmol) in H 2 O (20 ml) with sodium 4-fluorobenzoate (1.62 g, 10 mmol) in H 2 O (50 ml) at room temperature. The mixture was filtered and set aside to crystallize at ambient temperature for a week, giving blue single crystals.
supplementary materials sup-2 Refinement Atoms H41 and H42 (for water molecules) were located in a difference Fourier map and isotropically refined. The C-bound H atoms were positioned geometrically with C-H = 0.93-0.97 Å, and constrained to ride on their parent atoms, with U iso (H) = 1.2-1.5U eq (C).

Special details
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.
Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > 2sigma(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.