Bis{2-[(2-furylmethyl)iminomethyl]-5-methoxyphenolato-κ2 N,O}zinc(II)

In the title complex, [Zn(C13H12NO3)2], the ZnII ion is located on a twofold rotation axis and is coordinated by two bidentate Schiff base ligands in a distorted tetrahedral environment. The complex molecules are stacked in columns along the b axis through C—H⋯O hydrogen bonds.

In the title complex, [Zn(C 13 H 12 NO 3 ) 2 ], the Zn II ion is located on a twofold rotation axis and is coordinated by two bidentate Schiff base ligands in a distorted tetrahedral environment. The complex molecules are stacked in columns along the b axis through C-HÁ Á ÁO hydrogen bonds.

C. Li
Comment Zinc(II) complexes with the chelate ligands are extensively investigated as models for the active site of carbonic anhydrase and other hydrolytically active enzymes (Greener et al., 1996;Gultneh et al., 1996). Zinc(II) complexes are also studied on the role of zinc(II) structural properties in protein folding (Aoki & Kimura, 2004). Interestingly, zinc(II) complexes are becoming important in pharmaceutical, dye, plastic industries and for liquid crystal technology (Csaszar et al., 1985). In addition, the furfuryl amine and its derivatives are widely used as bioactive antibacterial agents and as steel corrosion inhibitors in recent research (Ledovskikh & Camejo, 1993;Camejo et al., 1992). By taking the biological importance of furfurylamine into account, we designed the title complex containing nitrogen-oxygen donor atoms coordinated with zinc(II).
The title complex reported here is the mononuclear zinc(II) complex of Schiff-base ligand, derived from the condensation of 4-methoxysalicylaldehyde and furfuryl amine (Fig. 1). The zinc(II) atom has a distorted tetrahedral coordination formed by two N atoms and two O atoms from two Schiff-base ligands. The bond distances of Zn-O and Zn-N are 1.925 (3) and 1.984 (3) Å, respectively. The dihedral angle between the coordination planes (N1/Zn1/O1 and N1A/Zn1A/O1A) is 87.24 (8)° (symmetry code A: -x, y, 1/2 -z), which is slightly larger than that of 84.43 (6)° between the corresponding co- In the crystal structure, the molecules are linked via intermolecular C-H···O hydrogen bonds forming a column along the b axis (Fig. 2).
Experimental 4-Methoxysalicylaldehyde (304 mg, 2 mmol) and furfurylamine (194 mg, 2 mmol) were dissolved in an aqueous methanol solution (25 mL).The mixture was stirred at room temperature for 1 h to give a clear yellow solution, which was added to a solutionof Zn(NO 3 ) 2 .6H 2 O (298 mg, 1 mmol) in methanol (10 mL). The mixture was stirred for 30 min at room temperature to give a yellow solution and then filtered. The yellow single crystals suitable for X-ray analysis were obtained by slowly evaporating the above filtrate at room temperature. The crystals were isolated and dried in a vacuum desiccator containing

Refinement
All the H atoms were placed in geometrically idealized positions and constrained to ride on their parent atoms, with C-H distances of 0.93-0.97 Å, and with U iso (H) = 1.2U eq (C) or 1.5U eq (methyl C). A rigid bond restraint was applied for atoms C11 and C12.  Fig. 1. The molecular structure of the title compound, with the atom labeling scheme. Displacement ellipsoids are drawn at the 30% probability level. The suffix A corresponds to symmetry code -x, y, 1/2 -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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )
x y z U iso */U eq