The title compound, (C4H12N2)[Ce2(C4H4O4S)4(H2O)2]- 3H2O, features a polymeric anion with a centrosymmetric Ce2O2 core and a Ce Ce distance of 4.3625 (4) A ° . The anions form ribbons {[Ce2(C4H4O4S)4(H2O)2]2}n extending along [100]. The doubly protonated piperazinium cations reside on centers of inversion and link the polymeric ribbons via N—H O hydrogen bonding. Each CeIII cation is tencoordinated by an O2S donor set from two tridentate sulfanediyldiacetate (tda) ligands, one water molecule and three other tda O donors from adjacent {Ce(tda)2(H2O)} units in a distorted bicapped cubic environment. Additional O— H O hydrogen bonding involving the coordinated and solvent water molecules is also present. H atoms of the crystal water molecules could not be located and were not included in the refinement.
