4-Bromo-2-[(E)-(2-{2-[(2-{[(E)-5-bromo-2-hydroxybenzylidene]amino}phenyl)sulfanyl]ethylsulfanyl}phenyl)iminomethyl]phenol

The asymmetric unit of the title compound, C28H22Br2N2O2S2, comprises half of a Schiff base ligand, the whole molecule being generated by a crystallographic inversion center located at the mid-point of the C—C bond of the central methylene segment. Intramolecular O—H⋯N and O—H⋯S hydrogen bonds make S(6) and S(5) ring motifs, respectively. In the crystal, there are no significant intermolecular interactions.

The asymmetric unit of the title compound, C 28 H 22 Br 2 N 2 O 2 S 2 , comprises half of a Schiff base ligand, the whole molecule being generated by a crystallographic inversion center located at the mid-point of the C-C bond of the central methylene segment. Intramolecular O-HÁ Á ÁN and O-HÁ Á ÁS hydrogen bonds make S(6) and S(5) ring motifs, respectively. In the crystal, there are no significant intermolecular interactions.
The asymmetric unit of the title compound, Fig. 1, comprises half of a Schiff base ligand. The whole molecule is generated by a crystallographic inversion center located in the middle of the C14-C14 i bond of the methylene segment [Symmetry code: (i) -x, -y+1, -z+1]. The bond lengths (Allen et al., 1987) and angles are within the normal ranges.
There are no significant intermolecular interactions in the crystal structure.

Experimental
The title compound was synthesized by adding 5-bromosalicylaldehyde (2 mmol) to a solution of 2-(2-(2-aminophenylthio)ethylthio)benzenamine (1 mmol) in ethanol (30 ml). The mixture was refluxed with stirring for half an hour. The resultant solution was filtered. Light-yellow needle-like crystals of the title compound, suitable for X-ray structure analysis, were obtained by slow evaporation of a solution in ethanol at room temperature over several days.

Refinement
The O-bound H atom was located in a difference Fourier map and constrained to refine on the parent atom with U iso (H) = 1.5U eq (O). The C-bound H atoms were included in calculated positions and treated as riding atoms: C-H = 0.93 and 0.97 Å for CH and CH 2 H atoms, respectively, with U iso (H) = 1.2 U eq (C).

Computing details
Data collection: APEX2 (Bruker, 2005); cell refinement: SAINT (Bruker, 2005); data reduction: SAINT (Bruker, 2005); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009  where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max = 0.001 Δρ max = 0.38 e Å −3 Δρ min = −0.55 e Å −3 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.