Bis[4-chloro-2-(iminomethyl)phenolato]copper(II)

In the title mononuclear copper(II) complex, [Cu(C7H5ClNO)2], the Cu atom, situated on an inversion center, is four-coordinated, in a slightly distorted square-planar geometry, by the N- and O-donor atoms of two symmetry-related 4-chloro-2-(iminomethyl)phenolate Schiff base ligands.

In the title mononuclear copper(II) complex, [Cu(C 7 H 5 Cl-NO) 2 ], the Cu atom, situated on an inversion center, is fourcoordinated, in a slightly distorted square-planar geometry, by the N-and O-donor atoms of two symmetry-related 4-chloro-2-(iminomethyl)phenolate Schiff base ligands.

Related literature
For the isotypic Ni(II) complex, see: Hong (2009). For bioinorganic chemistry and the coordination chemistry of copper(II) complexes, see: Datta et al. (2008); Diallo et al.
Financial support from Jiaying University Research Fund is gratefully acknowledged.  Datta et al., 2008;Khalaji et al., 2009). As a further study of the structures of such complexes, the crystal structure of the title mononuclear copper(II) complex is reported here. The title complex is isostructural with the nickel(II) complex of the same ligand, 4-Chloro-2-(iminomethyl)phenolate, reported on recently by (Hong, 2009).
The molecular structure of the title complex is illustrated in Fig. 1, and geometrical parameters are given in the archived CIF. The Cu II atom lies on an inversion center and is four-coordinated in a square-planar geometry by the N-and O-donor atoms of two Schiff base ligands. The whole molecule of the complex is approximately coplanar with mean deviation from the least-squares plane of 0.021 (2) Å.

S2. Experimental
5-Chloro-2-hydroxybenzaldehyde (0.2 mmol, 31.3 mg), copper(II) acetate monohydrate (0.1 mmol, 20.0 mg) and three drops of ammonia (30%) were mixed in 10 ml of methanol. The final solution was stirred for 10 min and allowed to stand in air for two days, yielding blue needle-like crystals of the title compound.

Figure 1
The structure of the title compound, showing the atom-numbering scheme and displacement ellipsoids drawn at the 30% probability level. where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max < 0.001 Δρ max = 0.48 e Å −3 Δρ min = −0.57 e Å −3 Special details Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s 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 > σ(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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )
x y z U iso */U eq