Heterometallic coordination polymers containing unique inorganic chain of [LnIII2CuII3(OH)4]: syntheses, structures and magnetism

Heterometallic compounds of [Ln2Cu3(OH)4(pyba)8(H2O)2]n (1–5) (Hpyba = 4-(4-pyridyl)benzoic acid, Ln = La 1, Pr 2, Sm 3, Eu 4, Gd 5) were hydrothermally synthesized by using lanthanide oxides, Hpyba, and copper halide as raw materials. Structurally, the two-dimensional frameworks of 1–5 possess the very original heterometallic chain moiety of [LnIII2CuII3(μ3-OH)4], which is the first inorganic chain in 3d–4f chemistry. Variable temperature magnetic susceptibility studies show that 5 displays weak antiferromagnetic coupling between the neighboring Gd(III) and Cu(II) ions.