Hydrothermal synthesis, crystal structure and properties of a novel chain coordination polymer constructed by tetrafunctional phosphonate anions and cobalt ions

• The tetrafunctional phosphonate ligand was used as the ligand.
• A novel chain structure can be formed by A-type rings and B-type rings.
• Two types of rings can form a 1D double-channel structure, along the c-axis.

A novel cobalt phosphonate, [Co(HL)(H2O)3]n (1) (L=N(CH2PO3H)33−) has been synthesized by hydrothermal reaction at 150 °C and structurally characterized by X-ray diffraction, infrared spectroscopy, elemental and thermogravimetric analysis. Complex 1 features a 1D chain structure with double-channel built from CoO6 octahedra bridged together by the phosphonate groups. Each cobalt ion is octahedrally coordinated by three phosphonate oxygen atoms and three water molecules. The coordinated water molecules can form the hydrogen bonds with the phosphonate oxygen atoms to link the 1D chains, building a 2D layered structure, further resulting in a 3D network. The luminescence spectrum indicates an emission maximum at 435 nm. The magnetic susceptibility curve exhibits a dominant antiferromagnetic behavior with a weakly ferromagnetic component at low temperatures.

The connectivity between cobalt ions and the ligands results in a chain structure with a 1D double-channel structure, which is constructed by A-type subrings and B-type subrings.Figure optionsDownload as PowerPoint slide