title: Crystal structure of poly[[hexa-qua-1κ(4) O,2κ(2) O-bis-(μ3-pyridine-2,4-di-car-box-ylato-1κO (2):2κ(2) N,O (2');1'κO (4))cobalt(II)-strontium(II)] dihydrate].
abstract: In the title polymeric complex, {[CoSr(C7H3NO4)2(H2O)6]·2H2O} 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-di-carboxyl-ate (pydc(2-)) ligands and two terminal water mol-ecules in a slightly distorted octa-hedral geometry, to form a trans-[Co(pydc)2(H2O)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 mol-ecules. The coordination geometry of the Sr(II) atom can be best described as a distorted dodeca-hedron. Each Sr(II) ion bridges four [Co(pydc)2(H2O)2](2-) units by four COO(-) groups of four pydc(2-) ligands to form a three-dimensional network structure. Two additional solvent water mol-ecules 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.
authors.affiliation: College of Chemical Engineering, Huanggang Normal University, Huanggang 438000, People's Republic of China.
authors.forename: Zhaojun
authors.initials: Z
authors.lastname: Yu
authors.affiliation: College of Chemical Engineering, Huanggang Normal University, Huanggang 438000, People's Republic of China.
authors.forename: Peng
authors.initials: P
authors.lastname: Jiang
authors.affiliation: College of Chemical Engineering, Huanggang Normal University, Huanggang 438000, People's Republic of China.
authors.forename: Yanmei
authors.initials: Y
authors.lastname: Chen
keywords: crystal structure; heterometallic complex; pyridine-2,4-di­carb­oxy­lic acid heterometallic complex