Hydrothermal synthesis, crystal structure and magnetic properties of a copper(II) phosphonate

Abstract

The treatment of 3-ammonium-1-hydroxypropylidene-1,1′-bisphosphonate (H₇ahdp) and 4,4′-bipy with CuCl₂ · 2H₂O resulted in a metal phosphonate [Cu(H₅ahdp) · H₂O] _n . Its crystal structure has been characterized by single X-ray crystallography. Although there is no 4,4′-bipy in the lattice structure, it plays a very important role in forming the one-dimensional chain of the polymer. Hydrogen bonds link the chains into a 3D network. The dinuclear secondary building units are observed in the compound. The determination of variable-temperature magnetic susceptibilities (5 ∼ 300 K) shows weak intrachain antiferromagnetic coupling between copper(II) centers. The magnetic data were fitted to the appropriate equations derived from the Hamiltonian H = −2JS ₁ S ₂, giving the parameter J = −25.78 cm⁻¹. Its thermal properties were also investigated.

Keywords:

• Hydrothermal synthesis
• Cu(II) phosphonate
• Crystal structure
• Magnetic properties

Acknowledgement

The authors thank the National Natural Science Foundation of China (Nos. 20471053 and 20501017) for financial support.