Bis{2,4-dibromo-6-[(E)-(4-fluorobenzyl)iminomethyl]phenolato-κ2 N,O}zinc

In the title Schiff base complex, [Zn(C14H9Br2FNO)2], the ZnII atom is located on a twofold rotation axis and is coordinated by two O and two N atoms from two symmetry-related bidentate Schiff base ligands in a compressed tetrahedral geometry. The bond lengths and bond angles are within normal ranges. The dihedral angle between the least-squares planes of the aromatic rings within each ligand is 82.76 (17)°.

In the title Schiff base complex, [Zn(C 14 H 9 Br 2 FNO) 2 ], the Zn II atom is located on a twofold rotation axis and is coordinated by two O and two N atoms from two symmetryrelated bidentate Schiff base ligands in a compressed tetrahedral geometry. The bond lengths and bond angles are within normal ranges. The dihedral angle between the leastsquares planes of the aromatic rings within each ligand is 82.76 (17) .

Related literature
For the coordination ability of Schiff bases ligands, see: Rodriguez Barbarin et al. (1994). For photochromism and thermochromism in Schiff bases, see: Cohen (1964).

Experimental
Crystal data [Zn(C 14  Data collection: RAPID-AUTO (Rigaku, 1998); cell refinement: RAPID-AUTO; data reduction: CrystalStructure (Rigaku/MSC, 2004); 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: SHELXL97. Schiff bases ligands have been used with remarkable success in the field of coordination chemistry over past decades (Rodriguez Barbarin et al., 1994). Schiff bases complexs show photochromism and thermochromism in the solid state by proton transfer from the hydroxyl O atom to the imine N atom (Cohen et al.,1964). Here we report on a new Schiff bases complex.
The molecular structure of title complex as illustrated in Fig.1. The dihedral angle between two benzenes rings is 83.281 (4)°. The Zn 2+ atom is located on a twofold rotation axis in a compressed tetrahedral geometry and is is coordinated by two O atoms and two N atoms. The Zn1-O1 distance of 1.9311 (1)Å is shorter than the distance of Zn1-N1[2.0268 (4)Å](table 1) The bond lengths and bond angles in title complex are within normal ranges. 3,5-dibromo-2-hydroxybenzal dehyde(10mmol,2.80g) and (4-fluorophenyl)methanamine (10mmol,1.25g) dissolved in ethanol respectively. Then put them together and the solution was refluxed for 0.5h. After evaporation,a crude product was recrystallized twice from ethanol to give a pure yellow product.

Refinement
All H atoms were placed in geometrically idealized positions and constrained to ride on their parent atoms (C-H = 0.93 %A) and Uiso(H) values equal to 1.2 Ueq(C).

Computing details
Data collection: RAPID-AUTO (Rigaku, 1998); cell refinement: RAPID-AUTO (Rigaku, 1998); data reduction: CrystalStructure (Rigaku/MSC, 2004); 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: SHELXL97 (Sheldrick, 2008).  The structure of the title complex, showing 30% probability displacement ellipsoids and the atom-numbering scheme. 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.