Synthesis and characterization of new coordination polymers generated from oxadiazole-containing ligand and inorganic M(II) [M = Cu(II), Co(II)] salts

The coordination chemistry of the oxadiazole-containing ligand 2,5-bis(4-pyridyl)-1,3,4-oxadiazole (L5) with inorganic Cu(II) and Co(II) salts has been investigated. Three new coordination polymers (1-3) and one H-bonded polymer (4) were prepared by solution reactions. [Cu(L5)(H2O)(SO4)].2(H2O) (1) adopts a novel chiral three-dimensional motif with rhombus channels (ca. 6.04 x 14.09 Angstrom). [Co(L5)(CH3OH)(2)(SO4)](CH3OH)(H2O)(3.5) (2) features a novel two-dimensional network. [Cu(L5)(2)(H2O)(2)](L5)(2)(ClO4)(2)(CH3OH)(H2O) (3) features a two-dimensional rhombus-grid-type layer with inner grid cavity dimensions of 13.22 x 13.22 Angstrom(2). Compound 4, however, is a molecular complex that is bound together by strong N ... H-O and O ... H-O hydrogen bonds into a three-dimensional H-bonded network.