(2-{[2-(1H-Benzimidazol-2-yl-κN 3)phenyl]iminomethyl-κN}-5-methylphenolato-κO)chloridozinc(II)

In the title mononuclear complex, [Zn(C21H16N3O)Cl], the ZnII ion is coordinated in a distorted tetrahedral geometry by two benzimidazole N atoms and one phenolate O atom from the tridentate Schiff base ligand and a chloride ligand. The benzimidazole ring system forms dihedral angles of 26.68 (9) and 56.16 (9)° with the adjacent benzene ring and the methylphenolate group benzene ring, respectively. In the crystal, molecules are linked by N—H⋯Cl hydrogen bonds into chains along [100]. Furthermore, weak C—H⋯O and C—H⋯π interactions, in addition to π–π interactions with centroid–centroid distances in the range 3.5826 (13)–3.9681 (13) Å, are also observed.

In the title mononuclear complex, [Zn(C 21 H 16 N 3 O)Cl], the Zn II ion is coordinated in a distorted tetrahedral geometry by two benzimidazole N atoms and one phenolate O atom from the tridentate Schiff base ligand and a chloride ligand. The benzimidazole ring system forms dihedral angles of 26.68 (9) and 56.16 (9) with the adjacent benzene ring and the methylphenolate group benzene ring, respectively. In the crystal, molecules are linked by N-HÁ Á ÁCl hydrogen bonds into chains along [100]. Furthermore, weak C-HÁ Á ÁO and C-HÁ Á Á interactions, in addition tointeractions with centroid-centroid distances in the range 3.5826 (13)-3.9681 (13) Å , are also observed.

Experimental
The title compound was synthesized by adding 2-hydroxy-4-methylbenzaldehyde (0.136 g, 1.0 mmol) to a solution of 2-(2-aminophenyl)-1H-benzimidazole (0.209 g, 1.0 mmol) in ethanol (30 mL). The color of the resulting solution was pale-yellow. Upon adding zinc chloride (0.136 g, 1.0 mmol), the color of the solution turned golden-yellow. The mixture was refluxed with stirring for 3 hrs. Yellow block-shaped single crystals of the title compound suitable for x-ray structure determination were obtained from ethanol by slow evaporation at room temperature after several days.
supplementary materials sup-2 Refinement H atom attached to N2 was located in a difference map and refined isotropically. The remaining H atoms were positioned geometrically and allowed to ride on their parent atoms, with d(C-H) = 0.93 Å for aromatic and CH; and 0.96 Å for CH 3 .
The U iso values were constrained to be 1.5U eq of the carrier atom for methyl H atoms and 1.2U eq for the remaining H atoms.
A rotating group model was used for the methyl groups. The highest residual electron density peak is located at 0.89 Å from Zn1 and the deepest hole is located at 0.74 Å from Zn1. Fig. 1. The molecular structure of the title compound, with 50% probability displacement ellipsoids. Crystal data [Zn(C 21 Glazer, 1986) operating at 120.0 (1) K.

Figures
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.