Synthesis, Structure And Properties Of Rare Earth Complexes Of Ferrocene Acid

In this paper, treatments of p-ferrocenylbenzoate [p-HOOCH₄C₆Fc, Fc = (η5-C₅H₅)Fe(η5-C₅H₄)] with Ln(NO₃)₃·6H₂O afford a series of p-ferrocenylbenzoate lanthanide complexes {[Ln(OOCH₄C₆Fc)₄(H₂O)₂](H₃O)}_n [Ln = Ce (1), Pr (2), Sm (3), Eu (4), Gd (5), Tb (6), Dy (7) & Lu (8)]. Furthermore, complexes 1 and 2 are structurally characterized by means of X-ray single-crystal diffraction. This series of complexes are characterized by elemental analysis, IR, UV and TG.Complexes {[Ce(OOCH₄C₆Fc)2(μ₂-η²-OOCH₄C₆Fc)2(H₂O)₂](H₃O)}_n (1) and {[Pr(OOCH₄C₆Fc)₂(μ₂-η²-OOCH₄C₆Fc)₂(H₂O)₂](H₃O)}_n (2) are isostructure. Ln(III) ions are bridged byμ₂-η²--OOCH₄C₆Fc forming a one-dimensional double-bridged infinite chain. Each Ln(III) ion adopts a dodecahedron coordination environment with eight coordinated oxygen atoms from two terminal monodentate coordinated FcC6H4COO- units, two terminal monodentate coordinated H2O molecules, and fourμ₂-η²--OOCH₄C₆Fc units.The fluorescencet analysis shows that complexes 4 and 6 exhibit characteristic fluorescence of lanthanide ions.The variable-temperature magnetic properties of complexes 5 and 7 have been investigated over the temperature range 2-300 K at 500 Oe. The results show that two complexes exhibit very strong antiferromagnetic interaction.