catena-Poly[[[(acetato-κ(2) O,O′)cadmium]-μ-acetato-κ(3) O,O′:O′-μ-{1,2-bis­[4-(pyridin-3-yl)pyrimidin-2-ylsulfan­yl]ethane}-κ(2) N (4),N (4′)] trihydrate]

The title compound, {[Cd(CH(3)COO)(2)(C(20)H(16)N(6)S(2))]·3H(2)O}(n), exists as a one-dimensional zigzag polymer in which the Cd(II) ion shows a seven-coordinate [CdO(5)N(2)] distorted penta­gonal–bipyramidal geometry with the N atoms in axial positions and an N—Cd—N angle of 176.94 (13)°. The metal atoms are bridged by 1,2-bis­[4-(pyridin-3-yl)pyrimidin-2-ylsulfan­yl]ethane ligands, giving a polymeric chain extending along the b axis. Adjacent chains related by an inversion center are further bridged by Cd—O bonds formed between the O atom of one of the acetate ligands and the metal atom. The five Cd—O bond lengths are in the range 2.329 (3)–2.485 (3) Å. There are π–π stacking inter­actions between the aromatic rings of adjacent polymeric chains, the centroid–centroid distances being 3.556 (3) and 3.698 (3) Å, organizing the chains into a three-dimensional framework. This framework is additionally stabilized by extensive O—H⋯O and O—H⋯N hydrogen bonding between water mol­ecules and the ligands.