catena-poly[[[diaqua(pyridine-2-carboxamide-N-1,O)copper(II)]-mu-(sulfato-O : O ')]monohydrate]

The new title Cu-II complex of pyridine-2-carboxamide (pca, C6H6N2O), {[CU( SO4)(pca)(H2O)(2)]. H2O}(n), has been synthesized and its crystal structure determined, It forms two crystallographically independent polymeric [Cu(H2 O)(2)(pca)(SO4)](infinity) chains in which the sulfate ion adopts a bridgin g position between two Cu atoms, coordinating via two of its O atoms, with Cu-O bond lengths in the range 2.318(1)-2.455(1) Angstrom. The pca ligand i s coordinated through the ring N and amide O atoms, forming a five-membered chelate ring with Cu-N distances of 2.010 (1) and 1.985 (1) Angstrom, and Cu-O distances of 1.964(4) and 1.985(1) Angstrom. The base of the elongated square-bipyramidal Cu-II coordination is completed by two Cu-O(H2O) bonds with lengths in the range 1.961(1)-1.975(1) Angstrom. The polymeric chains are connected by two types of hydrogen bonds, namely, N-H ... O bonds betwe en amino N and sulfate O atoms, and O-H ... O bonds between the uncoordinat ed H2O molecule and sulfate ions. The influence of the observed hydrogen bo nds on the hard structural parameters, such as bond lengths and angles, is analysed.