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

Abstract

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 × 14.09 Å). [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 × 13.22 Ų. 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.