Diaqua­bis­(4-meth­oxy­benzoato-κO)bis­(nicotinamide-κN (1))nickel(II) dihydrate

In the mononuclear title compound, [Ni(C(8)H(7)O(3))(2)(C(6)H(6)N(2)O)(2)(H(2)O)(2)]·2H(2)O, the Ni(II) ion is located on a crystallographic inversion center. The asymmetric unit further contains one 4-meth­oxy­benzoate anion, one nicotinamide (NA) ligand and one coordinated and one uncoordinated water mol­ecule; all ligands are monodentate. The four O atoms in the equatorial plane around the Ni(II) ion form a slightly distorted square-planar arrangement, while the slightly distorted octa­hedral coordination is completed by the two pyridine N atoms of the NA ligands in the axial positions. The dihedral angle between the carboxyl­ate group and the attached benzene ring is 7.2 (1)°, while the pyridine and benzene rings are oriented at a dihedral angle of 72.80 (4)°. An intra­molecular O—H⋯O hydrogen bond links the uncoordinated water mol­ecule to one of the carboxyl­ate groups. In the crystal structure, inter­molecular O—H⋯O, N—H⋯O and C—H⋯O hydrogen bonds link the mol­ecules into a three-dimensional network.