(2,2′-Bipyridyl-κ2 N,N′)chlorido(dl-threoninato-κ2 N,O 1)copper(II) monohydrate

In the title compound, [Cu(C4H8NO3)Cl(C10H8N2)]·H2O, the CuII atom is in a slightly distorted square-pyramidal coordination geometry with the basal plane defined by the two N atoms of the bipyridine ligand and the N and O atoms from the threoninate ion and the apical site occupied by the Cl atom. In the crystal, intermolecular O—H⋯O, N—H⋯O, O—H⋯Cl, C—H⋯O and C—H⋯Cl interactions link the molecules into a three-dimensional network. A π–π interaction with a centroid–centroid distance of 3.461 (1) Å is also present.

In the title compound, [Cu(C 4 H 8 NO 3 )Cl(C 10 H 8 N 2 )]ÁH 2 O, the Cu II atom is in a slightly distorted square-pyramidal coordination geometry with the basal plane defined by the two N atoms of the bipyridine ligand and the N and O atoms from the threoninate ion and the apical site occupied by the Cl atom. In the crystal, intermolecular O-HÁ Á ÁO, N-HÁ Á ÁO, O-HÁ Á ÁCl, C-HÁ Á ÁO and C-HÁ Á ÁCl interactions link the molecules into a three-dimensional network. Ainteraction with a centroid-centroid distance of 3.461 (1) Å is also present.
All parameters in compound, (Fig. 1), are within normal range. The Cu II is in a slightly distorted square-pyramidal coordination geometry, with the basal plane being defined by N1 and N2 atoms from the bipyridine group and N3 and O1 atoms from the threoninato group. The apical position is occupied by atom Cl1. The N3-H2N3···O1W interaction linked the water molecule with the main compound.
The pH of the resulting solution was then adjusted to pH 8 by adding a few drops of NaOH aqueous solution. The blue precipitate formed was filtered and single crystals suitable for X-ray diffraction were obtained by recrystallization of the complex.

Refinement
The water molecule's hydrogen atoms were located in a difference map and refined using a riding model, with U iso (H) = 1.5U eq (O). H atoms attached to N and other O atoms were located in a difference Fourier map and were freely refined. The remaining H atoms were positioned geometrically [C-H = 0.93 to 0.98 Å] and refined using a riding model, with U iso (H) = 1.2 or 1.5 U eq (C). A rotating-group model was applied for the methyl group.  (2,2'-Bipyridyl-κ 2 N,N')chlorido (DL-threoninato-

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.