Two unusual self-threading frameworks self-assembled from mixed ligands and cobalt/zinc ions

Abstract

Reactions of Co^II or Zn^II nitrate with mixed ligands norfloxacin (H-Norf) and 1,4-benzenedicarboxylic acid (H₂bdc) under hydrothermal conditions afford two isostructural compounds [Co₃(bdc)₂(Hbdc)₂(H-Norf)₂(H₂O)₄] (1) and [Zn₃(bdc)₂(Hbdc)₂(H-Norf)₂(H₂O)₄] (2). An eye-catching structure feature of these two compounds is that each rhombic window within the sheet is threaded by two dangling H-Norf ligands belonging to the sheet itself, showing the self-threading feature. Equally interesting is that the packing of these layers gives rise to a 3D self-threading network if interlayer H-bonds are taken into account. Thermal stability analyses of these two compounds and the magnetic property of complex 1 were also studied in this paper.