Aquabis(4-fluorobenzoato-κO)bis(nicotinamide-κN 1)copper(II) nicotinamide hemisolvate trihydrate

The asymmetric unit of the title compound, [Cu(C7H4FO2)2(C6H6N2O)2(H2O)]·0.5C6H6N2O·3H2O, contains two aquabis(4-fluorobenzoato)bis(nicotinamide)copper(II) molecules, one nicotinamide solvent molecule and six water molecules. The CuII ion is coordinated by two O atoms from two 4-fluorobenzoate ligands, two N atoms from two nicotinamide ligands and one water O atom in a distorted square-pyramidal geometry. In the crystal, O—H⋯O, O—H⋯N and N—H⋯O hydrogen bonds consolidate the crystal packing, which also exhibits π–π interactions between the aromatic rings [centroid–centroid distances 3.692 (2)–3.794 (2) Å].

The asymmetric unit of the title mononuclear Cu II complex ( Fig. 1 (Hökelek 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 NA (1.22 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 two weeks, giving blue single crystals.

Refinement
Atoms H71, H72, H141, H142, H161, H162, H171, H172, H181, H182, H191, H192, H201, H202, H211 and H212 (for water molecules) were located in a difference Fourier map and were refined by applying restraints. The N-bound and Cbound H-atoms were positioned geometrically with N-H = 0.86 Å, for NH 2 H-atoms, and C-H = 0.93 Å, for aromatic H-atoms, and constrained to ride on their parent atoms, with U iso (H) = 1.2 × U eq (C,N). Fig. 1. The content of asymmetric unit of the title compound showing the atomic numbering scheme and 50% probability displacement ellipsoids. Crystalline water molecules and hydrogen atoms have been omitted for clarity.

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.