catena-Poly[[aqua­(1,10-phenanthroline)cadmium(II)]-μ-benzene-1,4-di­carboxyl­ato]

The title compound, [Cd(C(8)H(4)O(4))(C(12)H(8)N(2))(H(2)O)](n), is a new coordination polymer of benzene-1,4-dicarboxyl­ate with cadmium(II) and 1,10-phenanthroline. The Cd(II) ion is coordinated by two N atoms from the 1,10-phenanthroline mol­ecule, three O atoms from two crystallographically independent benzene-1,4-dicarboxyl­ate ligands and the O atom of a coordinated water mol­ecule, forming a heavily distorted octa­hedron. The 1,10-phenanthroline ligand is approximately planar within 0.073 (4) Å. The two different benzene-1,4-dicarboxyl­ate ligands each coordinate to two Cd(II) ions in bidentate and monodentate modes, forming an infinite zigzag chain. Adjacent chains are packed tightly by strong π–π inter­actions [centroid–centroid distances = 3.851 (2) and 3.859 (2) Å] between the aromatic rings of the benzene-1,4-dicarboxyl­ate ligand and the 1,10-phenanthroline of a neighboring chain, forming a sheet parallel to (011). Different sheets are linked together via O—H⋯O hydrogen bonds between the coordinated water mol­ecules and the O atoms of the carboxyl­ate groups, forming a three-dimensional network.