[2,2′-Dihydroxy-N 2,N 2′-(3-hydroxyiminopentane-2,4-diyl)dibenzohydrazidato]copper(II)

The CuII atom in the title complex, [Cu(C19H17N5O5)], is coordinated by two N atoms and two O atoms of one 2,2′-dihydroxy-N 2,N 2’-(3-hydroxyiminopentane-2,4-diyl)dibenzohydrazidate ligand, exhibiting a distorted square-planar geometry. The dihedral angle between the two benzene rings in the oxime hydrazone is 7.62 (15)°. The molecular configuration is stabilized by intramolecular O—H⋯N hydrogen bonds. Pairs of centrosymmetrically related molecules are linked into dimers by two intermolecular C—H⋯O hydrogen bonds. Each dimer is further connected to four neighboring dimers via four O—H⋯O hydrogen bonds, forming an extended two-dimensional structure. The oxime O atom is disordered over two orientations in a 2:1 ratio.

The Cu II atom in the title complex, [Cu(C 19 H 17 N 5 O 5 )], is coordinated by two N atoms and two O atoms of one 2,2 0dihydroxy-N 2 ,N 2 '-(3-hydroxyiminopentane-2,4-diyl)dibenzohydrazidate ligand, exhibiting a distorted square-planar geometry. The dihedral angle between the two benzene rings in the oxime hydrazone is 7.62 (15) . The molecular configuration is stabilized by intramolecular O-HÁ Á ÁN hydrogen bonds. Pairs of centrosymmetrically related molecules are linked into dimers by two intermolecular C-HÁ Á ÁO hydrogen bonds. Each dimer is further connected to four neighboring dimers via four O-HÁ Á ÁO hydrogen bonds, forming an extended two-dimensional structure. The oxime O atom is disordered over two orientations in a 2:1 ratio.
As shown in Figure 1, the copper atom in the title complex has a square-planar coordination geometry, the four donors are two hydrazine nitrogen atoms and two carboxyl oxygen atoms in the oxime hydrazone ligand. The bond lengths of Cu-N and Cu-O in the square planar complex are similar to those in this type of copper complex (Suleiman Gwaram et al., 2010;Qin et al., 2010). The whole oxime hydrazone ligand is not planar; the dihedral angle between the two benzene rings in the oxime hydrazone ligand is 7.62 (15)°.
There are intramolecular O-H ···N hydrogen bonds, and intermolecular oxime-phenol O-H···O hydrogen bonds and intermolecular C-H···O hydrogen bonds in the title complex. The interatomic distance of O3A -O5 ii (symmetry code ii, 1/ 2+x, 1/2-y, 1/2+z) is 2.643 (3)Å. It means that there may exist O-H (oxime group) ···O (phenol) hydrogen bonds, although the hydrogen atom in N-O-H has not been found. These intermolecular O-H···O and C-H···O hydrogen bonds result in an extended two-dimensional layer structure (see Figure 2).
To the solution B was added the solution A slowly. The reaction mixture was stirred and refluxed for 2 hours to give a green solution. The deep blue crystals of the title complex were formed upon slow evaporation at about 297 K after 20 d.

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.