Crystal structure of catena-poly[[di­aqua(4,5-di­aza­fluoren-9-one-κ(2) N,N′)cadmium]-μ-2-hydroxy-5-sulfonato­benzoato-κ(3) O (1),O (1′):O (5)]

In the polymeric title compound, [Cd(C(7)H(4)O(6)S)(C(11)H(6)N(2)O)(H(2)O)(2)](n), the Cd(2+) atom is seven-coordinated by two water O atoms, by three O atoms from two 2-hy­droxy-5-sulfonato­benzoate (Hssal(2−)) ligands and by two N atoms from a 4,5-di­aza­fluoren-9-one (Dafo) ligand in a distorted penta­gonal–bipyramidal geometry. The Cd(2+) atoms are monodentately coordinated by the sulfonate group of one Hssal(2−) ligand and bidentately coordinated by the carboxyl­ate group of another Hssal(2−) ligand, generating zigzag chains running parallel to [010]. The chains are linked by O—H⋯O hydrogen bonds into a three-dimensional architecture.