title: Poly[diaqua-(μ(3)-pyridine-3,5-dicarboxyl-ato-κN:O:O)copper(II)].
abstract: The title complex, [Cu(C(7)H(3)NO(4))(H(2)O)(2)](n), was prepared under hydro-thermal reaction conditions. In the crystal structure, the Cu(II) cation is located on a twofold rotation axis and is coordinated by two carboxyl-ate O atoms and one N atom from three pyridine-3,5-dicarboxyl-ate (PDA) anions and two water mol-ecules with a distorted trigonal-bipyramidal geometry. The tridentate PDA anion is also located on the twofold rotation axis and bridges the Cu(II) cations to form a two-dimensional polymeric layer. O-H⋯O hydrogen bonding between layers links the two-dimensional layers into a three-dimensional supra-molecular framework.
authors.affiliation: School of Chemical Science and Technology, Key Laboratory of Medicinal Chemistry for Natural Resources, Ministry of Education, Yunnan University, Kunming 650091, People's Republic of China.
authors.forename: Lin
authors.initials: L
authors.lastname: Du
authors.forename: Li-Nan
authors.initials: LN
authors.lastname: Li
authors.forename: Qi-Hua
authors.initials: QH
authors.lastname: Zhao