Chlorido{5,5′-dimethoxy-2,2′-[1,2-phenylenebis(nitrilomethylidyne)]diphenolato-κ4 O,N,N′,O′}manganese(III)

In the title complex, [Mn(C22H18N2O4)Cl], the MnIII centre is in a distorted square-pyramidal configuration, with the basal plane formed by the N2O2 donors of the tetradentate Schiff base dianion; the two phenolate O atoms and the two imine N atoms are each mutually cis. The chloride ion occupies the apical position. The dihedral angle between the two outer phenolate rings of the tetradentate Schiff base ligand is 16.44 (9)°. The central benzene ring makes dihedral angles of 10.64 (9) and 25.17 (10)° with the two outer phenolate rings. In the crystal structure, weak C—H⋯O and C—H⋯Cl interactions link the molecules into wave-like face-to-face double layers along the c direction. A π–π interaction involving the two outer phenolate rings is observed, the centroid–centroid distance being 3.743 (11) Å.

In the title complex, [Mn(C 22 H 18 N 2 O 4 )Cl], the Mn III centre is in a distorted square-pyramidal configuration, with the basal plane formed by the N 2 O 2 donors of the tetradentate Schiff base dianion; the two phenolate O atoms and the two imine N atoms are each mutually cis. The chloride ion occupies the apical position. The dihedral angle between the two outer phenolate rings of the tetradentate Schiff base ligand is 16.44 (9) . The central benzene ring makes dihedral angles of 10.64 (9) and 25.17 (10) with the two outer phenolate rings. In the crystal structure, weak C-HÁ Á ÁO and C-HÁ Á ÁCl interactions link the molecules into wave-like face-to-face double layers along the c direction. Ainteraction involving the two outer phenolate rings is observed, the centroid-centroid distance being 3.743 (11) Å .
2008b). We report here the synthesis and structure of (I), Fig. 1, another five-coordinate Mn III complex of a closely-related ligand.
In (I), the Mn III complex shows a slightly distorted square-pyramidal geometry involving N1, N2, O1 and O2 atoms of the In the crystal packing (Fig. 2), weak C-H···O and C-H···Cl interactions (Table 1) link the molecules into wave like face-to-face double layers along the c direction. The crystal is stabilized by these weak C-H···O and C-H···Cl interactions.

Experimental
The title compound was synthesized by adding 2-hydroxy-4-methoxybenzaldehyde (0.610 g, 4 mmol) to a solution of o-phenylenediamine (0.216 g, 2 mmol) in ethanol 95% (30 ml). The mixture was refluxed with stirring for half an hour. Manganese chloride tetrahydrate (0.394 g, 2 mmol) in ethanol (10 ml) was then added, followed by triethylamine (0.5 ml, 3.6 mmol). The mixture was refluxed at room temperature for three hours. A brown precipitate was obtained, washed with about 5 ml ethanol, dried, and then washed with copious quantities of diethylether. Brown single crystals of the title compound suitable for x-ray structure determination were recrystallized from methanol by slow evaporation of the solvent at room temperature after two weeks.

Refinement
All H atoms were placed in calculated positions with d(C-H) = 0.93 Å and U iso (H) = 1.2U eq (C) for aromatic and CH, and with d(C-H) = 0.96 Å and U iso (H) = 1.5U eq (C) for CH 3 . A rotating group model was used for the methyl groups. The highest residual electron density peak is located at 0.70 Å from C2 and the deepest hole is located at 0.53 Å from Mn1. Fig. 1. The asymmetric unit of (I), showing 50% probability displacement ellipsoids and the atomic numbering.

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.  (3)