title: catena-Poly[[[diaqua-bis(2-methyl-6-oxo-1,6-dihydro-3,4'-bipyridine-5-carbo-nitrile)copper(II)]-μ-sulfato] tetra-hydrate].
abstract: In the title polymer, {[Cu(SO(4))(C(12)H(9)N(3)O)(2)(H(2)O)(2)]·4H(2)O}(n), both the metal center and the sulfate anion are located on a twofold axis. The Cu(II) ion is coordinated by two pyridyl N atoms from two symmetry-related organic ligands, two O atoms from two symmetry-related water mol-ecules, and two O atoms from two symmetry-related sulfate anions, resulting in a distorted octa-hedral geometry. The sulfate anions act as μ(2)-bridges and connect metal ions, forming a one-dimensional chain along the b axis. The three-dimensional crystal structure is established through inter-molecular N-H⋯O and O-H⋯O hydrogen bonds involving the organic ligands, sulfate anions, coordinated and uncoordinated water mol-ecules, and through π-π inter-acting 2-pyridone rings, with centroid-centroid separations of ca 3.96 Å and tilt angles of ca 2.62°.
authors.affiliation: College of Sciences, Henan Agricultural University, Zhengzhou 450002, People's Republic of China.
authors.forename: Cao-Yuan
authors.initials: CY
authors.lastname: Niu
authors.forename: Ai-Min
authors.initials: AM
authors.lastname: Ning
authors.forename: Chao-Ling
authors.initials: CL
authors.lastname: Feng
authors.forename: Yu-Li
authors.initials: YL
authors.lastname: Dang
authors.forename: Chun-Hong
authors.initials: CH
authors.lastname: Kou