catena-Poly[bis[(1,10-phenanthroline)nickel(II)]-mu-3,6-dicarboxycyclohexane-1,2,4,5-tetracarboxylato].

In the title compound, [Ni2(C12H8O12)(C12H8N2)2]n, the 3,6-dicarboxycyclohexane-1,2,4,5-tetracarboxylate (H2chhc4-) anion has crystallographically imposed C(2) symmetry and bridges the six-coordinate Ni atoms to generate polymeric infinity1[Ni2(H2chhc)2/2(C12H8N2)2] chains extending in the [010] direction. The coordination polymer chains are linked into a three-dimensional framework by O-H...O and C-H...O hydrogen bonds.