title: Crystal structure of poly[μ2-aqua-aqua-(μ2-4-nitro-2,5,6-trioxo-1,2,5,6-tetra-hydro-pyridin-3-olato)hemi-μ4-oxalato-barium(II)].
abstract: In the title coordination polymer, [Ba(C5HN2O6)(C2O4)0.5(H2O)2] n , the tenfold coordination of the Ba centre consists of four O atoms from the two 4-nitro-2,5,6-trioxo-1,2,5,6-tetra-hydro-pyridin-3-olate (L) anions, three O atoms of two oxalate anions and three water mol-ecules. The Ba-O bond lengths fall in the range 2.698 (3)-2.978 (3) Å. The L ligand chelates two Ba atoms related by a screw axis, leading to formation of fused five- and six-membered chelate rings. Due to the bridging function of the ligands and water mol-ecules, the complex monomers are connected into polymeric two-dimensional layers parallel to the bc plane. Inter-molecular O-H⋯O hydrogen bonds link these layers into a three-dimensional supra-molecular framework.
authors.affiliation: Al Muthanna University, Samawah, Al Mutanna, Iraq.
authors.forename: Rusul
authors.initials: R
authors.lastname: Alabada
authors.affiliation: Peoples' Friendship University of Russia, 6 Miklukho-Mallaya, 117198 Moscow, Russian Federation.
authors.forename: Olga
authors.initials: O
authors.lastname: Kovalchukova
authors.affiliation: Kurnakov Institute of General and Inorganic Chemistry RAS, 31 Leninskiy Avenue, 119991 Moscow, Russian Federation.
authors.forename: Irina
authors.initials: I
authors.lastname: Polyakova
authors.affiliation: Peoples' Friendship University of Russia, 6 Miklukho-Mallaya, 117198 Moscow, Russian Federation.
authors.forename: Svetlana
authors.initials: S
authors.lastname: Strashnova
authors.affiliation: Kurnakov Institute of General and Inorganic Chemistry RAS, 31 Leninskiy Avenue, 119991 Moscow, Russian Federation.
authors.forename: Vladimir
authors.initials: V
authors.lastname: Sergienko
keywords: barium(II) compound; crystal structure; oxalate; two-dimensional coordination polymer