catena-Poly[[[diaqua­(1,10-phenanthroline-κ(2) N,N′)cobalt(II)]-μ-1H-benzimidazole-5,6-dicarboxyl­ato-κ(2) N (3):O (6)] sesquihydrate}

In the title compound, {[Co(C(9)H(4)N(2)O(4))(C(12)H(8)N(2))(H(2)O)(2)]·1.5H(2)O}(n), the Co(II) atom is hexa­coordinated by one N atom and one O atom from two symmetry-related 1H-benzimidazole-5,6-dicarboxyl­ate ligands, two N atoms from one 1,10-phenanthroline ligand (phen) and two water mol­ecules. The dihedral angle between the 1H-benzimidazole-5,6-dicarboxyl­ate and 1,10-phenanthroline ligands is 74.41 (4)°. The crystal packing is governed by inter­molecular O—H⋯O and N—H⋯O hydrogen-bonding inter­actions. All water (coordin­ating and lattice) mol­ecules take part in the hydrogen-bonding inter­actions. In addition, there are π–π stacking inter­actions between inversion-related phen ligands, the shortest centroid–centroid distance being 3.7536 (16) Å. One of the two lattice water molecules shows half-occupancy.