Bis[bis(1-oxo-2-pyridyl)aminato]copper(II) tetrahydrate

In the title compound, [Cu(C10H8N3O2)2]·4H2O, the CuII ion has a distorted octahedral coordination formed by four O [Cu—O = 2.051 (3)–2.083 (4) Å] and two N [Cu—N = 1.985 (4) and 1.996 (4) Å] atoms from two tridentate bis(1-oxo-2-pyridyl)aminate ligands. In the two ligands, the pyridyl rings form dihedral angles of 21.0 (1) and 15.5 (1)°. The crystal packing exhibits an extensive network of O—H⋯O hydrogen bonds and π–π interactions proved by short distances of 3.650 (1) and 3.732 (2) Å between the centroids of pyridyl rings of neighbouring molecules.


Bis[bis(1-oxo-2-pyridyl)aminato]copper(II) tetrahydrate
Liang-Gui Wang S1. Comment Bis(amidopyridine) ligands have been widely explored in coordination chemistry for building various novel structural architectures and functional solid materials. Besides their diverse coordination modes, amide groups of ligands have proved to be useful in self-assembly, since they give predictable patterns of hydrogen bonding that can add extra dimensionality and helicity to the supramolecular structures (Patra et al., 2004). The modified bis(1-oxo-2-pyridyl)aminato ligand and its complexes have been recently reported (Liu et al., 2007). In this paper, we report the synthesis and crystal structure of the title compound, (I).
The Cu II atom in (I) ( The crystal packing exhibits π-π interactions ( Table 1) and an extensive network of O-H···O hydrogen bonds (Table   2).

S2. Experimental
Bis(1-oxo-2-pyridyl)aminato (0.062 g, 0.28 mmol), CuCl2 (0.024 g, 0.13 mmol), were added distilled water(12 mL), the mixture was heated for three hours under reflux. during the process stirring and influx were required. The resultant was kept at room temperature, three days later some single crystals of the size suitable for X-Ray diffraction measurement.

S3. Refinement
All H atoms attached to C atoms and N atom were fixed geometrically and treated as riding with C-H = 0.93 Å (benze ring) with U iso (H) = 1.2U eq (C or N). H atoms of the water molecules were located in difference Fourier maps and included in the subsequent refinement using restraints (O-H = 0.85 (4) Å and H···H = 1.42 (4) Å), and treated as riding with View of (I) showing the atom-labelling scheme and 30% probability displacement ellipsoids.

Bis[bis(1-oxo-2-pyridyl)aminato]copper(II) tetrahydrate
Crystal data [Cu(C 10  where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max < 0.001 Δρ max = 0.60 e Å −3 Δρ min = −0.46 e Å −3 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.