(Cyclohexanecarboxylato)bis(di-2-pyridylamine)zinc(II) nitrate monohydrate

In the title compound, [Zn(C7H11O2)(C10H9N3)2]NO3·H2O, the ZnII atom is five-coordinated by two bidentate di-2-pyridylamine ligands and one O atom from a cyclohexanecarboxyate anion, resulting in a ZnON4 square-based pyramidal coordination for the metal ion with the O atom in one of the basal positions. In the crystal, the components interact by way of O—H⋯O, O—H⋯N and N—H⋯O hydrogen bonds.

In the title compound, [Zn(C 7 H 11 O 2 )(C 10 H 9 N 3 ) 2 ]NO 3 ÁH 2 O, the Zn II atom is five-coordinated by two bidentate di-2pyridylamine ligands and one O atom from a cyclohexanecarboxyate anion, resulting in a ZnON 4 square-based pyramidal coordination for the metal ion with the O atom in one of the basal positions. In the crystal, the components interact by way of O-HÁ Á ÁO, O-HÁ Á ÁN and N-HÁ Á ÁO hydrogen bonds.

Related literature
For background to acid and amine metal complexes and their molecular architectures, see: Yang et al. (2004). For reference structural data, see: Allen et al. (1987).

S1. Comment
There has been much research interest in the acid and amine metal complexes due to their molecular architectures (e.g. Yang et al., 2004). In this work, we report here the crystal structure of the title compound, (I). In (I), all bond lengths are within normal ranges (Allen et al., 1987) (Fig. 1). The Zn II atom is five-coordinated by four N atoms from di-2-pyridylamine and one O atom from cyclohexanecarboxylic acid.

S3. Refinement
The N-and O-bound H atoms were located in a difference map and their positions were freely refined. The C-bound H atoms were positioned geometrically (C-H = 0.93 Å for the aromatic H atoms and C-H = 0.96 Å for the aliphatic H atoms) and were refined as riding, with U iso (H) = 1.2U eq (C).  The molecular structure of (I) showing 30% probability displacement ellipsoids.

(Cyclohexanecarboxylato)bis(di-2-pyridylamine)zinc(II) nitrate monohydrate
Special details Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s 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 > 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.