Aqua{4,4′,6,6′-tetrachloro-2,2′-[(2,2-dimethylpropane-1,3-diyl)bis(nitrilomethanylylidene)]diphenolato}zinc

The asymmetric unit of the title compound, [Zn(C19H16Cl4N2O2)(H2O)], comprises two crystallographically independent molecules. The geometry around the ZnII atoms is distorted trigonal–bipyramidal, supported by the N2O2 donor atoms of the tetradentate Schiff base and a coordinating water molecule. The dihedral angles between the benzene rings in the two molecules are 34.10 (15) Å and 30.61 (15) Å. In the crystal, neighbouring independent molecules are linked by pairs of O—H⋯O hydrogen bonds, forming dimers with R 2 2(6) ring motifs, and by O—H⋯Cl hydrogen bonds. There are short Cl⋯Cl [3.4728 (16), 3.4863 (16), and 3.388 (1) Å] contacts present, and molecules are also linked by C—H⋯O and π–π [centroid–centroid distance = 3.671 (2) Å] interactions.

The resultant solution was filtered. Light-green single crystals of the title compound, suitable for X-ray structure determination, were recrystallized from ethanol by slow evaporation of the solvents at room temperature over several days.

Refinement
The H atoms of the water molecules were located in a difference Fourier map and were constrained to ride on the parent O atoms, with U iso (H) = 1.5U eq (O). The C-bound H-atoms were included in calculated positions and treated as riding atoms: C-H = 0.93, 0.96 and 0.97 Å for CH, CH 3 and CH 2 H-atoms, respectively, with U iso (H) = k × U eq (parent C-atom), where k = 1.5 for CH 3 H-atoms and = 1.2 for other H-atoms.

Figure 1
The molecular structure of the title compound, showing 40% probability displacement ellipsoids and the atom numbering. The C-bound H atoms have been omitted for clarity.

Figure 3
The packing diagram of the title compound viewed down the c-axis, showing the Cl···Cl interactions (dashed lines). The hydrogen atoms have been omitted for clarity.

Crystal data
[Zn (C 19 H 16 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.