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

Abstract

In the title complex, [Ni(C20H22N2O4)]·0.5H2O, the NiII ion is in a slightly distorted square-planar geometry involving an N2O2 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.