title: Poly[[diaqua-(μ-4,4'-bipyridine N,N'-di-oxide-κ(2)O:O')(μ-terephthalato-κ(2)O(1):O(4))cobalt(II)] 4,4'-bipyridine N,N'-dioxide monosolvate].
abstract: In the title compound, {[Co(C(8)H(4)O(4))(C(10)H(8)N(2)O(2))(H(2)O)(2)]·C(10)H(8)N(2)O(2)}(n), the Co(II) atom, lying on an inversion center, is hexa-coordinated in a distorted octa-hedral geometry defined by two O atoms from two terephthalate (tp) ligands, two O atoms from two 4,4'-bipyridine N,N'-dioxide (bpydo) ligands and two water mol-ecules. The coordinated tp and bpydo ligands and uncoordinated bpydo mol-ecule all have an inversion center. The Co(II) atoms are connected by the tp and bpydo ligands into a layer parallel to (111). In the crystal, O-H⋯O hydrogen bonds link the uncoordinated bpydo mol-ecules and the layers into a three-dimensional supra-molecular structure. Intra-layer O-H⋯O hydrogen bonds and π-π inter-actions [centroid-to-centroid distances = 3.6643 (13) and 3.8048 (13) Å] are also observed.
authors.affiliation: State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022,  People's Republic of China.
authors.forename: Xin
authors.initials: X
authors.lastname: Ge
authors.forename: Shu-Yan
authors.initials: SY
authors.lastname: Song