catena-Poly[[[aqua(1,10-phenanthroline-κ2N,N′)cadmium(II)]-μ-pyridine-2,3-dicarboxylato-κ4N,O2:O3,O3′] dihydrate]

The title complex, {[Cd(C7H3NO4)(C12H8N2)(H2O)]·2H2O}n, is a one-dimensional coordination polymer, wherein the Cd atom is seven-coordinated by two 1,10-phenanthroline N atoms, one N and three O atoms from two different pyridine-2,3-dicarboxylate ligands, and one water molecule. It is further extended to a two-dimensional layer structure by hydrogen bonds and π–π stacking interactions [centroid-centroid distances of 3.560 (2) and 3.666 (2) Å]. There is a C4 water chain in the structure whose repeat unit contains four water molecules with O...O distances in the range 2.748 (3)–2.795 (4) Å. One of the two H atoms of each water of hydration is statistically distributed over two positions with equal occupancy