μ-Biphenyl-3,3′,4,4′-tetra­carboxyl­ato-κ(2) O (3):O (3′)-bis­[triaqua­(2,2′-bipyridyl-κ(2) N,N′)nickel(II)] hexa­hydrate

The asymmetric unit of the title complex, [Ni(2)(C(16)H(6)O(8))(C(10)H(8)N(2))(2)(H(2)O)(6)]·6H(2)O, contains one Ni(II) atom, one 2,2′-bipyridine ligand, three coordinated water mol­ecules, one-half of a fully deprotonated biphenyl-3,3′,4,4′-tetra­carboxyl­ate anion and three lattice water mol­ecules. The Ni(II) atom displays a distorted NiN(2)O(4) octa­hedral coordination formed by one carboxyl­ate O atom, three water O atoms and two N atoms of the chelating ligand. The complete biphenyl-3,3′,4,4′-tetra­carboxyl­ate ligand displays inversion symmetry and links two symmetry-related Ni(II) atoms into a binuclear complex. Neighbouring complex mol­ecules are linked through O—H⋯O hydrogen bonds into a three-dimensional structure. Additional O—H⋯O hydrogen bonds between the lattice water mol­ecules help to consolidate the crystal packing.