Crystal structure of poly[[hexa­qua-1κ(4) O,2κ(2) O-bis­(μ(3)-pyridine-2,4-di­car­box­ylato-1κO (2):2κ(2) N,O (2′);1′κO (4))cobalt(II)­strontium(II)] dihydrate]

In the title polymeric complex, {[CoSr(C(7)H(3)NO(4))(2)(H(2)O)(6)]·2H(2)O}(n), the Co(II) ion, which is situated on a crystallographic centre of inversion, is six-coordinated by two O atoms and two N atoms from two pyridine-2,4-di­carboxyl­ate (pydc(2−)) ligands and two terminal water mol­ecules in a slightly distorted octa­hedral geometry, to form a trans-[Co(pydc)(2)(H(2)O)(2)](2−) unit. The Sr(II) ion, situated on a C (2) axis, is coordinated by four O atoms from four pydc(2−) ligands and four water mol­ecules. The coordination geometry of the Sr(II) atom can be best described as a distorted dodeca­hedron. Each Sr(II) ion bridges four [Co(pydc)(2)(H(2)O)(2)](2−) units by four COO(−) groups of four pydc(2−) ligands to form a three-dimensional network structure. Two additional solvent water mol­ecules are observed in the crystal structure and are connected to the three-dimensional coordination polymer by O—H⋯O hydrogen bonds. Further intra- and intermolecular O—H⋯O hydrogen bonds consolidate the overall structure.