catena-Poly[[diaqua­bis­(formato-κO)cobalt(II)]-μ(2)-2,6-bis­(pyridin-4-yl)-4,4′-bipyridine-κ(2) N (2):N (6)]

In the title complex, [Co(CHO(2))(2)(C(20)H(14)N(4))(H(2)O)(2)](n), the Co(II) ion, lying on an inversion center, is six-coordinated by two O atoms from two monodentate formate ligands, two N atoms from two 2,6-bis­(pyridin-4-yl)-4,4′-bipyridine (4-pybpy) ligands and two water mol­ecules, displaying an octa­hedral geometry. The 4-pybpy ligand, having a twofold rotation axis, functions in a bridging coordination mode, connecting the Co(II) ions into a corrugated chain along [[Image: see text]01]. The chains are further linked into a three-dimensional supra­molecular network by O—H⋯O, C—H⋯N and C—H⋯O hydrogen bonds and π–π stacking inter­actions between the pyridine rings [centroid-to-centroid distance = 3.743 (2) Å].