Acetato(aqua){6,6′-dimethoxy-2,2′-[ethane-1,2-diylbis(nitrilomethanylylidene)]diphenolato}cobalt(III) methanol disolvate

In the title complex, [Co(C18H18N2O4)(C2H3O2)(H2O)]·2CH3OH, the CoIII atom is hexacoordinated by water and acetate groups in the axial positions and by the tetradentate Schiff base occupying equatorial positions. These axial bonds are longer than the equatorial bonds to the tetradentate Schiff base. Two molecules form a dimer through strong hydrogen bonds from the coordinated water of one molecule to the methoxy O atoms of an adjoining molecule. There is extensive intra- and intermolecular O—H⋯O hydrogen bonding between the coordinated water and acetate ligands and the methanol solvent molecules. In addition, there are weak intermolecular C—H⋯O interactions, which link the molecules into a three-dimensional array.

In the title complex, [Co(C 18 H 18 N 2 O 4 )(C 2 H 3 O 2 )(H 2 O)]Á-2CH 3 OH, the Co III atom is hexacoordinated by water and acetate groups in the axial positions and by the tetradentate Schiff base occupying equatorial positions. These axial bonds are longer than the equatorial bonds to the tetradentate Schiff base. Two molecules form a dimer through strong hydrogen bonds from the coordinated water of one molecule to the methoxy O atoms of an adjoining molecule. There is extensive intra-and intermolecular O-HÁ Á ÁO hydrogen bonding between the coordinated water and acetate ligands and the methanol solvent molecules. In addition, there are weak intermolecular C-HÁ Á ÁO interactions, which link the molecules into a three-dimensional array.
The structure consists of six coordinate Co(III) in a slightly distorted octahedral geometry with both methanol and water occupying the axial positions and a tetradentate Schiff base (N 2 O 2 ) which is in the equatorial plane. In addition there are two molecules of solvate methanol in the lattice (Fig. 1 There is extensive O-H···O intra-and intermolecular hydrogen bonding between the coordinated water and acetate moieties and the methanol solvate molecules (Fig. 2). In addition there are weak C-H···O intermolecular interactions.
These link the structure into a three-dimensional array.

Experimental
The synthesis of the ligand 3-methoxyethylenediaminebissalicylaldimine was accomplished by the reaction of the solution of (2 g, 33.3 mmol) of ethylenediamine in 10 ml methanol which was added to the solution of o-vanillin in 40 ml methanol dropwise using a glass pipette. The mixture was refluxed for 24 h. After solvent evaporation under reduced pressure yellow solids were obtained.
The complex was synthesized by mixing a solution of (0.25 g, 1 mmol) of Co(CH 3 COO) 2 . 4H 2 O in 5 ml me thanol with a solution of (0.33 g, 1 mmol) 3-methoxyethylenediaminebissalicylaldimine in 3 ml of dichloromethene. The mixture was stirred for 1 h at room temperature, filtered and layered with diethyl ether for crystallization. Crystals suitable for singlecrystal X-ray diffraction were obtained by slow evaporation.

Refinement
H atoms were placed in geometrically idealized positions and constrained to ride on their parent atoms with a C-H   The molecular packing for C 22 H 31 CoN 2 O 9 viewed along the a axis. O-H···O hydrogen bonding and weak C-H···O intermolecular interactions are shown by dashed lines.

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.

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