(μ-Butane-1,2,3,4-tetra­carboxyl­ato)bis­[triaqua­(1,10-phenanthroline)nickel(II)] hexa­hydrate

The asymmetric unit of the title compound, [Ni(2)(C(8)H(6)O(8))(C(12)H(8)N(2))(2)(H(2)O)(6)]·6H(2)O, contains a half of the centrosymmetric dinuclear complex mol­ecule and three uncoordinated water mol­ecules. In the dinuclear mol­ecule, two Ni(II) cations are bridged by the butane-1,2,3,4-tetra­carboxyl­ate (BTC(4−)) anion. Each Ni(II) atom is coordinated by two N atoms from the 1,10-phenanthroline ligand, one O atom from the BTC(4−) anion and three aqua ligands in a distorted octa­hedral geometry. Inter­molecuar O—H⋯O hydrogen bonds and π–π stacking inter­ations [centroid–centroid distances = 3.646 (2), 3.781 (2) and 3.642 (2) Å] consolidate the crystal packing.