Tris(1,10-phenanthroline-κ(2) N,N′)nickel(II) dinitrate tetra­hydrate

In the title complex, [Ni(C(12)H(8)N(2))(3)](NO(3))(2)·4H(2)O, the Ni(II) ion is octa­hedrally coordinated by three bidentate 1,10-phenanthroline ligands, each forming a five-membered chelate ring. In the crystal, O—H⋯O and C—H⋯O hydrogen bonds are present between the complex cations, nitrate anions and water mol­ecules. O—H⋯O hydrogen bonds between the uncoord­inated water mol­ecules lead to the formation of a four-membered ring water cluster, with a planar configuration. There were an additional five grossly disordered water mol­ecules in the asymmetric unit, which were removed by the subroutine SQUEEZE; these were were excluded in the calculation of the molecular weight, etc. π–π stacking inter­actions between the aromatic rings are also observed [centroid–centroid distances = 3.697 (2), 3.728 (2) and 3.761 (2) Å].