catena-Poly[[[diaquabis(pyridine-4-carboxamide-kappa N)copper(II)]-mu(2)-squarato-kappa O-1 : O-3] dihydrate]

Abstract

The asymmetric unit of the title compound, {[Cu(C4O4)(C-6-H6N2O),(H2O)(2)]center dot 2H(2)O}(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 Cu-II and the squarate ions are located on inversion centers. The Cu-II 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 Cu-II ions. These chains are held together by N-H center dot center dot center dot O and O-H center dot center dot center dot O intermolecular hydrogen-bond interactions, forming an extensive three-dimensional network.