title: Tetra-aqua-(2,2'-bipyridine-5,5'-dicarboxyl-ato-κN,N')nickel(II) dihydrate.
abstract: In the title compound, [Ni(C(12)H(6)N(2)O(4))(H(2)O)(4)]·2H(2)O, obtained from a basic solution of 2,2'-bipyridine-5,5'-dicarboxyl-ate and nickel(II) chloride in water, the central Ni(II) cation (site symmetry 2) is coordinated by two N atoms from the 2,2'-bipyridine-5,5'-dicarboxyl-ate ligand and four aqua O atoms. The N-Ni-N angle is 78.64 (8)°. Weak but significant π-π stacking inter-actions exist between the pyridine rings with a centroid-centroid distance of 3.652 (8) Å. In addition, four O atoms of the two carboxyl groups form hydrogen bonds with both coordinated and uncoordinated water mol-ecules, forming an infinite three-dimensional network.
authors.affiliation: Department of Chemistry, Mudanjiang Teachers College, Mudanjiang 157012, People's Republic of China.
authors.forename: Hua
authors.initials: H
authors.lastname: Yang