An unprecedented 3D honeycomb-shaped cobalt phosphonate containing sixfold helical chains: Synthesis, crystal structure and thermal stability

A new cobalt(II) phosphonate, [Co(aepa)(4,4′-bpy)(H2O)2]·2H2O 1 (H2aepa = 2-aminoethylphosphonic acid) has been hydrothermally synthesized and characterized by IR, elemental analysis, TGA and single crystal X-ray diffraction analysis. Compound 1 features a 3D alveolate network structure originating from the intertwist of the rare sixfold 1D helical chains, which are assembled from the coordination of the aepa2− ligands to the cobalt atoms.