Aqua(dicyanamido){μ-6,6′-dimethoxy-2,2′-[ethane-1,2-diylbis(nitrilomethylidyne)]diphenolato}nickel(II)sodium

The molecule of the title compound, [NaNi(C18H18N2O4)(C2N3)(H2O)], is approximately planar, with a maximum deviation from the molecular plane of 0.770 (5) Å. The coordination environment of the Ni2+ ion is distorted square-planar and it is N2O2 coordinated by the 6,6′-dimethoxy-2,2′-[ethane-1,2-diylbis(nitrilomethylidyne)]diphenolate Schiff base ligand. The Na+ atom is chelated by the four O atoms of the Schiff base ligand, a water ligand and a dicyanamide anion. The structure displays intermolecular O—H⋯N hydrogen bonding.

The molecule of the title compound, [NaNi(C 18 H 18 N 2 O 4 )-(C 2 N 3 )(H 2 O)], is approximately planar, with a maximum deviation from the molecular plane of 0.770 (5) Å . The coordination environment of the Ni 2+ ion is distorted square-planar and it is N 2 O 2 coordinated by the 6,6 0dimethoxy-2,2 0 -[ethane-1,2-diylbis(nitrilomethylidyne)]diphenolate Schiff base ligand. The Na + atom is chelated by the four O atoms of the Schiff base ligand, a water ligand and a dicyanamide anion. The structure displays intermolecular O-HÁ Á ÁN hydrogen bonding.
Data collection: APEX2 (Bruker, 2004); cell refinement: SAINT-Plus (Bruker, 2001); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL. The dicyanamide ligand N(CN) 2 , has attracted continuous attention in the past four years for the buildup of interesting extended architectures. Its versatile coordination behavior and its ability to organize solids into polymeric structures with a rich diversity of magnetic properties have attracted interest toward this research area (Ohba et al., 2000). N,N-disalicylideneethylenediamine type Schiff bases ligands present versatile steric, electronic and lipophilic properties (Correia et al. 2005). We report here the synthesis and crystal structure of the title compound. The molecular structure is shown in Fig.   1. The values of the geometric parameters in this compound are normal (Costes et al., 2004). Ni II and Na I are connected via two bridging O atoms of the ligand. The six-coordinate Na atom adopts a distorted octahedral coordination geometry while the four-coordinate Ni gives a planar coordination geometry.

S2. Experimental
A mixture of 6,6′-dimethoxy-2,2′-(ethane-1,2-diyldiiminodimethylene)diphenol (1 mmol) and nickel chloride (1 mmol) in methanol (15 ml) was stirred for 30 min and sodium dicyanamide (1 mmol) was added, stirred for another 15 min and then filtered. The resulting clear orange solution was vapor at room temperature for 7 d, after which large orange blockshaped crystals of the title complex suitable for X-ray diffraction analysis were obtained.

S3. Refinement
The H atoms were fixed geometrically and were treated as riding on their parent C atoms, with C-H distances in the range of 0.93-0.97 Å and with U iso (H) = 1.2U eq (parent atom), or U iso (H) = 1.5U eq (C methyl ).

Figure 1
The independent molecules of the title compound, showing 30% probability displacement ellipsoids and the atomnumbering scheme.

Aqua(dicyanamido){µ-6,6′-dimethoxy-2,2′-[ethane-1,2-diylbis(nitrilomethylidyne)]diphenolato}nickel(II)sodium
Crystal data [NaNi(C 18  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.