Dichloridobis[2-(2-furyl)-1-(2-furylmethyl)-1H-benzimidazole-κN 3]cadmium(II)

In the title complex, [CdCl2(C16H12N2O2)2], the CdII ion exhibits site symmetry 2. It shows a distorted tetrahedral coordination defined by two N atoms from symmetry-related 2-(2-furyl)-1-(2-furylmethyl)-1H-benzimidazole ligands and by two symmetry-related Cl atoms. Intramolecular C—H⋯O hydrogen bonds stabilize the molecular configuration. Adjacent molecules are linked through C—H⋯Cl hydrogen bonds into a network structure.


Comment
Benzimidazole and its derivatives have attracted interest because of their biological activities as well as their abilities to bind to different metal ions (Shen & Yuan, 2006;Yang et al., 2008). The Cd II ion is a good model atom to construct complexes owing to its property to form bonds with different donors simultaneously, and to its various coordination modes (Meng et al., 2004;Yang et al., 2010). In this work, we describe the synthesis and structure of the title complex, [CdCl 2 (C 16 H 12 N 2 O 2 ) 2 ], (I).
In the structure of (I), two 2-(furan-2-yl)-1-(furan-2-yl-methyl)-1H-1,3-benzimidazole ligands and two Cl atoms coordinate to the Cd II ion which is located on a twofold rotation axis. As expected, the Cd-Cl bond length is slightly longer than the Cd-N bond length. The environment around the Cd II ion can be best described as distorted tetrahedral (Fig.1).
Intramolecular C-H···O hydrogen bonds stabilize the molecular configuration and C-H···Cl hydrogen bonds between adjacent molecules consolidate the crystal packing.

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 supplementary materials sup-3 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 )