Bis(dicyanamido-κN 1)bis[2-(2-hydroxyethyl)pyridine-κ2 N,O]nickel(II)

In the title complex, [Ni{N(CN)2}2(C7H9NO)2], the NiII ion (site symmetry ) adopts a distorted trans-NiO2N4 octahedral geometry. In the crystal, intermolecular O—H⋯N hydrogen bonds link the molecules, forming a chain along the c axis.

In the title complex, [Ni{N(CN) 2 } 2 (C 7 H 9 NO) 2 ], the Ni II ion (site symmetry 1) adopts a distorted trans-NiO 2 N 4 octahedral geometry. In the crystal, intermolecular O-HÁ Á ÁN hydrogen bonds link the molecules, forming a chain along the c axis.

Bis(dicyanamido-κN 1 )bis[2-(2-hydroxyethyl)pyridine-κ 2 N,O]nickel(II)
Ling-Qian Kong, Xiu-Ping Ju and Da-Cheng Li S1. Comment In recent years there has been considerable interest in metal complexes supported by hydroxyethyl-pyridine,the ligand due to its versatile coordination activities and bridging function. (Sanudo et al., 2003;Boskovic et al., 2002). As an extension of this work, we have synthesized the title compound, (I), and report herein its crystal structure.
The complex ( Fig. 1) consists of two L2-(L = (hydroxyethyl)(pyridine)) ligands, one Ni II ion and two dicyanmiden ligands. The coordination geometry around the Ni center is octahedral with a NiN 4 O 2 ligand set (Table 1). Two atoms N1 of hydroxyethylpyridine ligand occpy the axial sites. In the crystal structure, intermolecular O-H···N hydrogen bonds link molecules to form a one-dimensional chain along to the c axis (Table 2).

S2. Experimental
2-Hydroxyethylpyridine (0.123 g, 1 mmol) was deprotonated by Et 4 NOH (25%) in the prensence of nickel nitrate hexahydrate (0.5 mmol, 0.127 g) in a mixture of methanol and acetonitrile (V/V = 1:1) after the solution was stirred at room temperature for 0.5 h. Sodium dicyanmiden (5 mmol 0.486 g) was added to the above solution and then further stirred for 1 h. The resulting clear solution was filtered and left to stand at room temperature. Green blocks of (I) were obtained by slow evaporation of the solvents within 2 weeks. MP = 518-520 K (decomp).

S3. Refinement
All H atoms were placed geometrically and treated as riding on their parent atoms with C-H = 0.93-0.  The structure of the title complex, showing 30% probability displacement ellipsoids. Atoms labelled with the suffix A are generated by the symmetry operation (-x + 1,-y,-z + 1). H atoms have been omitted for clarity.  The crystal packing of (I), viewed approximately along the c axis.

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )
x y z U iso */U eq