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

In the mononuclear title compound, [Ni(C₈H₇O ₃)₂(C₆H₆N₂O) ₂(H₂O)₂]·2H₂O, the Ni ^II ion is located on a crystallographic inversion center. The asymmetric unit further contains one 4-methoxy-benzoate 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 intra-molecular 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.