Poly[[[(2,2′-bipyridine-κ2 N, N′)cobalt(II)]-μ3-5-hydroxy­isophthalato-κ4 O, O′: O′′: O′′′] dihydrate].

In the title compound, {[Co(C8H4O5)(C10H8N2)]·2H2O]} n or {[Co(OH-BDC)(2,2′-bipy)]·2H2O]} n (where OH-H2BDC is 5-hydroxy­isophthalic acid and 2,2′-bipy is 2,2′-bipyridine), the Co atoms are chelated by two N atoms from the 2,2′-bipy ligand and by four O atoms from OH-BDC ligands in a highly distorted octa­hedral geometry. OH-BDC acts as a tetra­dentate ligand, with one carboxyl­ate group chelating one Co atom and the other binding in a monodentate fashion to two other Co atoms to form a one-dimensional zigzag chain. In the crystal structure, one of the solvent water mol­ecules lies on a crystallographic twofold axis. The one-dimensional mol­ecular chains are assembled into a two-dimensional network via O—H⋯O hydrogen-bonding inter­actions, while π–π stacking inter­actions generate a three-dimensional open framework between the two-dimensional networks. [ABSTRACT FROM AUTHOR]