Synthesis and characterization of nickel phosphonopropionate hybrid materials

Hydrothermal reaction of nickel acetate with 3-phosphonopropionic acid and 4,4′-bipyridine resulted in two novel phosphonate compounds Ni(HO3PC2H4COO)(4,4′-bpy)(H2O) · 0.5(4,4′-bpy) (bpy = bipyridine) (I) and Ni(O3PC2H4COOH)(4,4′-bpy)(H2O)3 · H2O (II). Single-crystal X-ray studies reveal that self-assemblies between the ligands and metal ion result in layer (I) and chain (II) structures. Magnetic measurement of I indicate there are ferromagnetic couplings between adjacent Ni2+ ions (C = 1.29 cm3 mol−1 K and θ = 2.25 K).