title: Diaqua-(5-carb-oxy-benzene-1,3-dicarboxyl-ato-κO,O)(6,6'-dimethyl-2,2'-bipyridine-κN,N')nickel(II) hepta-hydrate.
abstract: In the title compound, [Ni(C(9)H(4)O(6))(C(12)H(12)N(2))(H(2)O)(2)]·7H(2)O, the Ni(II) atom is six-coordinated by two O atoms from a chelating carboxyl-ate group of a 5-carb-oxy-benzene-1,3-dicarboxyl-ate ligand, two O atoms of two water mol-ecules and two N atoms from a 6,6'-dimethyl-2,2'-bipyridine ligand in a distorted octa-hedral geometry. The compound exhibits a three-dimensional supra-molecular structure composed of the complex mol-ecules and lattice water mol-ecules, which are linked together by inter-molecular O-H⋯O hydrogen bonds and partly overlapping π-π inter-actions between the pyridine and benzene rings [centroid-centroid distances = 3.922 (2) and 3.921 (2) Å]. One of the lattice water mol-ecules is disordered over two positions in an occupancy ratio of 0.521 (6):0.479 (6).
authors: North China University of Water Conservancy and Electric Power, Zhengzhou 450011,  People's Republic of China.
authors: Wen-Wen
authors: WW
authors: Shan
authors: Han-Lin
authors: HL
authors: Xiong
authors: Chong-Zhen
authors: CZ
authors: Mei