title: catena-Poly[[[diaquabis(pyridine-4-carboxamide-kappaN)copper(II)]-mu2-squarato-kappaO1:O3] dihydrate].
abstract: The asymmetric unit of the title compound, {[Cu(C4O4)(C6H6N2O)2(H2O)2].2H2O}n, consists of one pyridine-4-carboxamide (isonicotinamide or ina) ligand, one-half of a squarate dianion, a coordinated aqua ligand and a solvent water molecule. Both the CuII and the squarate ions are located on inversion centers. The CuII ions are octahedrally surrounded by four O atoms of two water molecules and two squarate anions, and by two N atoms of the isonicotinamide ligands. The crystal structure contains chains of squarate-1,3-bridged CuII ions. These chains are held together by N-H...O and O-H...O intermolecular hydrogen-bond interactions, forming an extensive three-dimensional network.
authors.affiliation: Department of Physics, Faculty of Arts and Sciences, Ondokuz Mayís University, TR-55139 Kurupelit Samsun, Turkey. iucar@omu.edu.tr
authors.forename: Ibrahim
authors.initials: I
authors.lastname: Uçar
authors.forename: Ahmet
authors.initials: A
authors.lastname: Bulut
authors.forename: Orhan
authors.initials: O
authors.lastname: Büyükgüngör