Honeycomb-like layered cobalt(II) phosphonate with [O2CCH(OH)PO3]3− as ligand: Hydrothermal synthesis, crystal structure, and magnetic properties

A new cobalt(II) phosphonate, [enH2]0.5[Co(pa)(H2O)] · H2O (1) (H3pa = hydroxy-phosphono-acetic acid, HO2CCH(OH)PO3H2; en = ethylenediamine), has been hydrothermally synthesized and structurally characterized. Compound 1 has a honeycomb-like layer structure which is composed of CoO6 octahedra and μ3-pa ligands with the protonated en and lattice water molecules stabilized between the layers. Magnetic studies indicate that 1 shows weak ferromagnetic behavior, spin-glass behavior, and metamagnetic behavior.