Aquachlorido{6,6′-dimethoxy-2,2′-[ethane-1,2-diylbis(nitrilomethanylylidene)]diphenolato-κ2 O 1,N,N′,O 1′}cobalt(III) dimethylformamide monosolvate

In the title compound, [Co(C18H18N2O4)Cl(H2O)]·C3H7NO, the CoIII ion is six-coordinated by a tetradentate 6,6′-dimethoxy-2,2′-[ethane-1,2-diylbis(nitrilomethanylylidene)]diphenolate ligand, with a chloride ion and an aqua ligand in the apical positions. The compound crystallized as a dimethylformamide (DMF) monosolvate. In the crystal, complex molecules are linked via O—Hwater⋯O hydrogen bonds to form a dimer-like arrangement. These dimers are linked via a C—H⋯Cl interaction, and the DMF molecule is linked to the complex molecule by C—H⋯O interactions.

In the title compound, [Co(C 18 H 18 N 2 O 4 )Cl(H 2 O)]ÁC 3 H 7 NO, the Co III ion is six-coordinated by a tetradentate 6,6 0dimethoxy-2,2 0 -[ethane-1,2-diylbis(nitrilomethanylylidene)]diphenolate ligand, with a chloride ion and an aqua ligand in the apical positions. The compound crystallized as a dimethylformamide (DMF) monosolvate. In the crystal, complex molecules are linked via O-H water Á Á ÁO hydrogen bonds to form a dimer-like arrangement. These dimers are linked via a C-HÁ Á ÁCl interaction, and the DMF molecule is linked to the complex molecule by C-HÁ Á ÁO interactions.
The molecular structure of the title compound is illustrated in Fig. 1. The Co III ion is coordinated to two N and two O atoms of the tetradentate 6,6′-dimethoxy-2,2′-[ethane-1,2-diylbis(nitrilomethanylylidene)]diphenolate ligand, a Clion and one water molecule. The compound crystallized with a molecule of dimethylformamide, used as solvent. The crystal structure of the ligand has been reported previously (Xia et al., 2006), as has the monohydrate form of the title complex (Xing, 2009). The Cl5-Co1-O5 bond angle is 178.77 (7)° suggesting that the Co III ion has a slightly distorted octahedral environment, with atoms N1, N2, O1 and O2 occupying the equatorial positions, while atoms Cl5 and O5 water occupy the axial positions.
In the crystal, complex molecules are linked via O-H water ···O hydrogen bonds to form a dimer-like arrangement. These dimers are linked via a C-H···Cl interaction, and the DMF molecule is linked to the complex molecule by C-H···O interactions (Table 1).

Experimental
A colourless solution of 6,6′-dimethoxy-2,2′-[ethane-1,2-diylbis(nitrilomethanylylidene)]diphenol (54.5 mg,0.2 mmol) in DMF (3 ml) was slowly added to a solution of CoCl 2 (64 mg, 0.2 mmol) in CH 3 CN(15 ml), forming a dark red solution that was stirred for 30 min at room temperature. Slow evaporation of the solvent at room temperature gave red block-like crystals of the title compound, suitable for X-ray analysis. The crystals were collected by filtration, washed with cold acetonitrile, and dried under vacuum (yield 77%).

Refinement
The water H atoms were located in an difference electron-density map and allowed to ride on the O atom with O-H = 0.96 Å. The C-bound H-atoms were included in calculated positions and treated as riding atoms: C-H = 0.93, 0.97 and 0.96 Å for CH, CH 2 , and CH 3 H-atoms, respectively, with U iso (H) = k × U eq (O,C), where k = 1.5 for OH and CH 3 Hatoms, and k = 1.2 for other H-atoms. program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figure 1
A view of the molecular structure of the title complex, with the atom numbering scheme. Displacement ellipsoids are drawn at the 50% probability level. where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max = 0.001 Δρ max = 0.70 e Å −3 Δρ min = −0.39 e Å −3 Special details Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell esds are taken into account in the estimation of distances, angles and torsion angles 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