{4,4′-Dichloro-2,2′-[2,2-dimethylpropane-1,3-diylbis(nitrilomethanylylidene)]diphenolato}copper(II)

In the title Schiff base complex, [Cu(C19H18Cl2N2O2)], the CuII ion is coordinated in a distorted square-planar environment by two N atoms and two O atoms of the tetradentate ligand. The dihedral angle between the benzene rings is 36.86 (14)°. In the crystal, molecules are linked into inversion dimers by pairs of weak C—H⋯O hydrogen bonds. In addition, π–π [centroid–centroid distance = 3.7279 (16) Å] and weak C—H⋯π interactions are observed.

In the title Schiff base complex, [Cu(C 19 H 18 Cl 2 N 2 O 2 )], the Cu II ion is coordinated in a distorted square-planar environment by two N atoms and two O atoms of the tetradentate ligand. The dihedral angle between the benzene rings is 36.86 (14) . In the crystal, molecules are linked into inversion dimers by pairs of weak C-HÁ Á ÁO hydrogen bonds. In addition, -[centroid-centroid distance = 3.7279 (16) Å ] and weak C-HÁ Á Á interactions are observed.

D-HÁ
The asymmetric unit of the title compound, Fig. 1, comprises a Schiff base complex. The bond lengths (Allen et al., 1987) and angles are within the normal ranges and are comparable to those in related structures (Kargar et al., 2012;Kargar et al., 2011;Ghaemi, et al., (2011).

Experimental
The title compound was synthesized by adding 5-dichloro-salicylaldehyde-2,2-dimethyl-1, 3-propanediamine (2 mmol) to a solution of CuCl 2 . 4H 2 O (2.1 mmol) in ethanol (30 ml). The mixture was refluxed with stirring for half an hour. The resultant solution was filtered. Dark-green single crystals of the title compound suitable for X-ray structure determination were recrystallized from ethanol by slow evaporation of the solvents at room temperature over several days.

Refinement
The H-atoms were included in calculated positions and treated as riding atoms: C-H = 0.93, 0.96 and 0.97 Å for CH, CH 3 and CH 2 H-atoms, respectively, with U iso (H) = k × U eq (C), where k = 1.5 for CH 3 H-atoms, and k = 1.2 for all other H-atoms.

{4,4′-Dichloro-2,2′-[2,2-dimethylpropane-1,3-diylbis(nitrilomethanylylidene)]diphenolato}copper(II)
Crystal data [Cu(C 19 H 18 (2) 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.