{4,4′-Dimeth­oxy-2,2′-[1,1′-(ethane-1,2-diyldinitrilo)diethyl­idyne]diphenolato}nickel(II) hemihydrate

In the title complex, [Ni(C(20)H(22)N(2)O(4))]·0.5H(2)O, the Ni(II) ion is in a slightly distorted square-planar geometry involving an N(2)O(2) atom set of the tetra­dentate Schiff base ligand. The asymmetric unit contains one mol­ecule of the complex and half a water solvent mol­ecule. The solvent water mol­ecule lies on a crystallographic twofold rotation axis. An inter­molecular O—H⋯O hydrogen bond forms an R (2) (1)(4) ring motif involving a bifurcated hydrogen bond to the phenolate O atoms of the complex. In the crystal structure, mol­ecules are linked by π–π stacking inter­actions, with centroid–centroid distances in the range 3.5310 (11)–3.7905 (12) Å, forming extended chains along the b axis. In addition, there are Ni⋯Ni and Ni⋯N inter­actions [3.4404 (4)–4.1588 (4) and 3.383 (2)–3.756 (2) Å, respectively] which are shorter than the sum of the van der Waals radii of the relevant atoms. Further stabilization of the crystal structure is attained by weak inter­molecular C—H⋯O and C—H⋯π inter­actions.