catena-Poly[(diaqua­cadmium)-μ-4,4′-[sulfonyl­bis­(1,4-phenyl­ene­oxy)]­di­acet­ato-κ(4) O,O′:O′′,O′′′]

In the title coordination polymer, [Cd(C(16)H(12)O(8)S)(H(2)O)(2)](n), the Cd(II) ion is situated on a crystallographic twofold rotation axis, being coordinated by four O atoms from two bidentate 4,4′-[sulfonyl­bis­(1,4-phenyl­ene­oxy)]diacetate (L) ligands and two water mol­ecules in a highly distorted CdO(6) octa­hedral geometry. Each complete ligand L, which is also generated by twofold symmetry with the S atom lying on the rotation axis, bridges two Cd(II) atoms to form a polymeric zigzag chain propagating in the [10-1] direction. O—H⋯O hydrogen bonds between the coordinated water mol­ecules and carboxyl­ate O atoms are involved in the packing.