Bis[μ-2-(pyridin-2-yl)ethanolato]bis[bromidocopper(II)]

The title compound, [Cu2Br2(C7H8NO)2], was synthesized by reaction of CuBr2 with 2-(pyridin-2-yl)ethanol (hep-H) in methanol. The asymmetric unit consists of one hep ligand and a CuBr unit. The Cu2+ ion is thereby coordinated by the N atom and the deprotonated hydroxy O atom in a distorted square-planar geometry that is completed by another O atom. The latter acts as bridging ligand towards the second, symmetry-equivalent, Cu atom, thus generating a centrosymmetric dimeric unit, with the inversion centre halfway between the Cu atoms. These units are linked via C—H⋯Br and C—H⋯O hydrogen bonds, leading to the formation of a hydrogen-bonded one-dimensional-polymeric chain along a..

The title compound, [Cu 2 Br 2 (C 7 H 8 NO) 2 ], was synthesized by reaction of CuBr 2 with 2-(pyridin-2-yl)ethanol (hep-H) in methanol. The asymmetric unit consists of one hep ligand and a CuBr unit. The Cu 2+ ion is thereby coordinated by the N atom and the deprotonated hydroxy O atom in a distorted square-planar geometry that is completed by another O atom. The latter acts as bridging ligand towards the second, symmetry-equivalent, Cu atom, thus generating a centrosymmetric dimeric unit, with the inversion centre halfway between the Cu atoms. These units are linked via C-HÁ Á ÁBr and C-HÁ Á ÁO hydrogen bonds, leading to the formation of a hydrogen-bonded one-dimensional-polymeric chain along a..

Experimental
A solution of hep-H (123 mg, 1.0 mmol) in 30 ml methanol was added to a 10 ml methanolic solution of CuBr 2 (223 mg, 1.0 mmol) and the resultant solution was stirred for 2 h at room temperature. The solution was then passed through filter paper (Whatman filter paper, 70 mm) in order to remove any unreacted materials. The filtrate was allowed to stand at room

Refinement
The hydrogen atoms were placed geometrically and treated as riding on their parent atoms, with C-H 0.95 (pyridyl), C-H 0.99 (methylene) Å [U iso (H) = 1.2U eq (C)]. Fig. 1. View of the molecular structure of the title compound with displacement ellipsoids drawn at the 50% probability level. Symmetry-related moiety generated by i: -x, -y, -z.

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.