Poly[diaqua-bis-(μ-4,4'-bipyridine-κ(2) N:N')bis-(ethane-1,2-diol-κO)bis(μ-sulfato-κ(2) O:O')dicobalt(II)].

In the title compound, [Co2(SO4)2(C10H8N2)2(C2H6O2)2(H2O)2] n , there are two crystallographically independent Co(II) ions, each of which lies on a twofold rotation axis and has a slightly distorted octa-hedral environment. One Co(II) ion is coordinated by two N atoms from two bridging 4,4'-bipyridine (4,4'-bipy) ligands, two O atoms from two sulfate ions and two O atoms from aqua ligands. The second Co(II) ion is similar but with ethane-1,2-diol ligands in place of water mol-ecules. The sulfate anions act as bridging ligands to link two adjacent Co(II) ions together, leading to the formation of linear ⋯Co1Co2Co1Co2⋯chains along the a axis. Adjacent chains are further bridged by 4,4'-bipy ligands, which are also located on the twofold rotation axis, resulting in a two-dimensional layered polymer extending parallel to (001). In the crystal, the layers are linked by extensive O-H⋯O hydrogen-bonding inter-actions involving the O atoms of the water mol-ecules and ethane-1,2-diol mol-ecules, resulting in a three-dimensional supra-molecular network.