In the title complex, {[Co(C10H8N2)(H2O)4](C11H10O5)}n, the unique CoII ion lies on an inversion center and is coordinated by two N atoms from two 4,4′-bipyridine read more ligands and four O atoms from four water molecules in a slightly bostik roll-cote distorted octahedral coordination geometry.The 4,4′-bipyridine ligands bridge CoII ions into a one-dimensional chain structure.In the crystal structure, intermolecular O—H.O hydrogen bonds link cations and anions into a three-dimensional network.The dianions are completely disordered about an inversion center.