Dichlorido(pyridine-κN)[2-(pyridinium-1-yl)acetato-κO]zinc(II)

In the title complex, [ZnCl2(C5H5N)(C7H7NO2)], the ZnII atom adopts a distorted tetrahedral coordination geometry [the smallest angle being 105.22 (15)° and the widest angle being 115.60 (16)°] that is formed from one monodentate carboxylate ligand, one pyridine ligand and two Cl atoms.

In the title complex, [ZnCl 2 (C 5 H 5 N)(C 7 H 7 NO 2 )], the Zn II atom adopts a distorted tetrahedral coordination geometry [the smallest angle being 105.22 (15) and the widest angle being 115.60 (16) ] that is formed from one monodentate carboxylate ligand, one pyridine ligand and two Cl atoms.

Dichlorido(pyridine-κN)[2-(pyridinium-1-yl)acetato-κO]zinc(II) Zhang Qun and Chen Jin-Xiang Comment
The study of synthetic active site analogues has made vast contribution to the understanding of the structure function relationship of many metalloenzymes (Holm et al., 2004). Since the coordination environment of many metalloenzyme active sites is made up of different donor groups, the interest of synthetic chemists has shifted toward the design of mixed ligands (Karambelkar et al., 2002). The title complex (I), has been prepared with the aim to mimic the structures and functions of the active sites of zinc metalloenzymes by using carboxylate ligand and pyridine ligand.
Complex (I) crystallizes in the monoclinic space group P21/c and the asymmetric unit contains one [C 12 H 12 Cl 2 N 2 O 2 Zn] molecule ( Figure 1). In the complex (I), the Zn atom is coordinated one monodentate carboxylate ligand, one pyridine group and two Cl atoms, hence forming a distorted tetrahedral geometry.

Experimental
The title complex was synthesized by reaction of N-(carboxymethyl)pyridinium bromide (1.09 g, 5 mmol) and ZnCl 2 (0.68 g, 5 mmol) in pyridine (10 ml). The solution was stirred for 2 h to afford white precipitates. The precipitates were collected by filtration, re-dissolved in H 2 O (5 ml) then allowed to stand for several days to produce white crystals (I).

Refinement
Carbon-bond H atoms were positioned geometrically (C-H = 0.93 Å for phenyl group), and were included in the refinement in the riding model approximation, with U iso (H) = 1.2U eq (C).  Ellipsoid plot of complex (I) at the 30% probability level. Hydrogen atoms are drawn as spheres of arbitrary radii.

Dichlorido(pyridine-κN)[2-(pyridinium-1-yl)acetato-κO]zinc(II)
Crystal data Special details Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s 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 > σ(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.