New Family of Heptanuclear Lanthanide {Ln(7)} Clusters: Synthesis, Structure, and Magnetic Studies

摘要

A new family of heptanuclear lanthanide complex Ln(7)(L)(2)(LH)(4)(dbm)(5)(OH)(2)(CH3OH)(4).xCHCl(3).yCH(3)OH.zH(2)O {Ln=Tb-III (1), Dy-III (2) and Er-III (3) and LH3=(E)-2-(hydroxymethyl)-6-(((2-hydroxyphenyl) imino) methyl)-4-methylphenol} in 1, x=6, y=3, z=3; in 2, x=5, y=1, z=6; and in 3, x=4, z=2 has been prepared in presence of lanthanide chloride(III) salts and beta-diketonate co-ligand dibenzoylmethane (dbm). Single crystal XRD reveals heptanuclear ensemble formed by collective action of two fully deprotonated L(3-) ligands, four double deprotonated LH(2-), two mu(3)-OH- ligands, five anionic dbm(-) beta-diketonate co-ligands and two terminal methanol solvent molecules. This heptanuclear unit comprises of two Dy-4(mu(2)-O)(5)(mu(3)-OH)(+6) core sharing a common metal vertex Dy1 through which centre of inversion has passed for overall molecule. All the complexes have been magnetically characterized and dynamic AC magnetic studies reveals slow relaxation of magnetism present in dysprosium analogue (2).