Aqua­(4,4′-bipyridine-κN)bis­(1,4-dioxo-1,4-dihydronaphthalen-2-olato-κ(2) O (1),O (2))zinc 4,4′-bipyridine mono­solvate dihydrate

The reaction of 2-hy­droxy-1,4-naphtho­quinone and 4,4′-bipyridine with zinc acetate produced the title compound, [Zn(C(10)H(5)O(3))(2)(C(10)H(8)N(2))(H(2)O)]·C(10)H(8)N(2)·2H(2)O. The bond lengths and angles around the metal atom indicate a deviation from octa­hedral geometry. The two naphtho­quinone ligands coordinate in a cis fashion, with the 4,4′-bipyridine ligand and the water mol­ecules completing the coordination sphere of the metal atom. The asymmetric unit contains also one free 4,4′-bipyridine mol­ecule and two uncoordinated water mol­ecules. These mol­ecules make contacts with the complex through O—H⋯N and O—H⋯O hydrogen bonds, creating a layer two-dimensional network parallel to (121).