Syntheses And Properties Of Co/Ni-Ln Heterometallic Clusters Based On 2,3-dichlorobenzoic Acid And 2,2'-bipyridine

In this paper,two series of 3d-4f heterometallic clusters[Ln₂Co₂(2,3-DCB)₁₀(2,2'-bpy)₂][Ln=Nd(1),Sm(2),Eu(3),Gd(4),Tb(5),Dy(6),Er(7),Yb(8)]and[Ln₂Ni₂(2,3-DCB)₁₀(2,2'-bpy)₂][Ln=Nd(9),Sm(10),Eu(11),Gd(12),Tb(13),Dy(14),Er(15),Yb(16)]have been successfully synthesized by selecting 2,3-dichlorobenzoic acid(2,3-HDCB)as the O-donor ligand,2,2'-bipyridine(2,2'-bpy)as the N-donor ligand as well as different rare earth nitrate and cobalt/nickel nitrate under solvothermal conditions.The obtained complexes 1–16 were characterized by single-crystal X-ray diffraction analysis,FT-IR spectrum,powder X-ray diffraction analysis and thermogravimetric analysis.Meanwhile,the magnetic properties of complexes 1–2,4–10 and 12–16 have been investigated.Single-crystal X-ray diffraction analysis indicates that complexes 1–8and 9–16 were isostructural,respectively,and all of them show zero-dimensional(0D)structures.In complexes 1–16,the 2,3-DCB anions bridge transition metal ions and rare earth ions through four types of different coordination modes into Co₂Ln₂/Ni₂Ln₂tetranuclear clusters.In addition,there are the?–?interactions between the 2,3-DCB anion and the 2,2'-bpy molecule,and adjacent zero-dimensional tetranuclear clusters can be connected by such the?–?interactions to form a two-dimensional(2D)supramolecular layer.Magnetic analysis reveals that complexes 4 and 12 show antiferromagnetic interactions between the Gd(III)and Co(II)/Ni(II)ions.Complexes 6,14 and 15 exhibit ferromagnetic couplings between the Dy(III)/Er(III)and Co(II)/Ni(II)ions.Complexes 6 and 14 display weak slow relaxation behaviors of magnetization under zero dc field.