{4,4′-Dibromo-2,2′-[2,2-dimethylpropane-1,3-diylbis(nitrilomethylidyne)]diphenolato-κ4 O,N,N′,O′}copper(II)

In the title compound, [Cu(C19H18Br2N2O2)], the CuII ion is in a tetrahedrally distorted planar geometry, involving two N and two O atoms from the tetradentate Schiff base ligand. Intermolecular C—H⋯O hydrogen bonds form an eight-membered R 2 2(8) motif. The dihedral angle betwen two benzene rings is 36.34 (9)°. There are intermolecular Cu⋯Br [3.4566 (5) Å] and Cu⋯·N [3.569 (3) Å] contacts, which are significantly shorter than the sum of van der Waals radii of the relevant atoms. These interactions, along with the intermolecular C—H⋯π and π–π [centroid–centroid distances of 3.709 (1) and 3.968 (2) Å] interactions, link neighbouring molecules into a one-dimensional infinite chain along the c axis.

Data collection: APEX2 (Bruker, 2007); cell refinement: SAINT (Bruker, 2007); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2003 (Elmali et al., 2000;Granovski et al.,1993). Transition metal complexes of Schiff base ligands are always of interest since they exhibit a marked tendency to oligomerize, thus leading to novel structural types, and also display a wide variety of magnetic properties (Blower, 1998;Shahrokhian et al., 2000). Many of the reported structural investigations of these complexes are discussed in some details in a review (Hodgson, 1975).
Tetradentate Schiff base metal complexes may form trans or cis planar or tetrahedral structures (Elmali et al., 2000).

Experimental
The title compound was prepared based on the reported method (Arici et al., 2001). Single crystals suitable for X-ray analysis were obtained from an ethanol solution at room temperature.

Refinement
H atoms were positioned geometrically and refined using a riding model, with C-H = 0.93 (aromatic), 0.97 (CH 2 ) and 0.96 (CH 3 ) Å and U iso (H) = 1.2 (1.5 for methyl groups) U eq (C). The highest difference peak is located 0.81 Å from Br2 and the deepest hole is located 0.76 Å from Cu1.
supplementary materials sup-2 Figures   Fig. 1. The molecular structure of the title compound, showing 50% probability displacement ellipsoids.