Bis{2-bromo-4-chloro-6-[(E)-(2,6-dimethylphenyl)iminomethyl]phenolato-κ2 N,O}cobalt(II)

In the title complex, [Co(C15H12BrClNO)2], the CoII ion is coordinated by two N,O-bidentate 2-bromo-4-chloro-6-[(E)-(2,6-dimethylphenyl)iminomethyl]phenolate ligands, generating a squashed CoN2O2 tetrahedral coordination geometry. The dihedral angles between the aromatic rings in the ligands are 82.60 (14) and 71.79 (14)°. The complex has approximate local noncrystallographic twofold symmetry. In the crystal, weak aromatic π–π stacking is observed [centroid–centroid separation = 3.6434 (18) Å].


Experimental
Crystal data [Co(C 15 Table 1 Selected bond lengths (Å ). mono-, bi-, tri-, and poly-nuclear Schiff-base complexes, so the design of metal-organic coordination polymers is of current interest in the fields of supramolecular chemistry and crystal engineering because of their potential applications as functional materials (Feng, et al., 2008;Liu, et al., 2009). Meanwhile, Schiff bases and their metal complexes exhibit biological activity as antibiotics, antiviral and antitumour agents because of their specific structures (Billson, et al., 2000;Carlton, et al., 1995). Thus, it is quite important to have a good understanding of the structure of such metal complexes.
In this paper, we report synthesis and crystal structure of a new cobalt(II) complex, bis[2-((E)-(2,6-dimethylphenylimino) methyl)-6-bromo-4-chlorophenol]cobalt(II). The structure of the complex had been established accurately from the X-ray single-crystal diffraction study. The Co(II) ion in the monomeric unit seems to reside in a distorted tetrahedral environment and bonds to two oxygen atoms and two nitrogen atoms from two Schiff bases.

Figure 1
The structure of the title complex in 30% probability ellipsoids. H atoms are deleted for clarity.  The crystal packing of the title complex, viewed along the a axis.

Bis{2-bromo-4-chloro-6-[(E)-(2,6-dimethylphenyl)iminomethyl]phenolato-κ 2 N,O}cobalt(II)
Crystal data  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