Five Rare μ4 -O-Centered Ln6 Clusters with Single-Molecule Magnet Behavior for Dy6.

Abstract

Five hexanuclear lanthanide clusters of composition [Ln6 (μ4 -O)2 (HCOO)2 L4 (HL')2 (dmf)2 ] [Ln=Dy (1), Er (2), Ho (3), Tb (4), Gd (5); H2 L=2-{[2-(hydroxymethyl)phenylimino]methyl}-6-methoxyphenol; H3 L'=3-{[2-(hydroxymethyl)phenylimino]methyl}benzene-1,2-diol; H3 L' was derived in situ from the H2 L ligand] were prepared under solvothermal conditions. The [Ln6 ] cores of 1-5 possess an unprecedented motif, namely, two tetrahedron Ln4 units sharing an edge and two vertices. The six LnIII ions of 1-5 are connected through two μ4 -O anions. Magnetic susceptibility studies reveal that complex 1 exhibits frequency dependence of the alternating current susceptibility typical of single-molecule magnets. Complex 1 possesses a relatively large energy barrier of 85 K among all of the reported Dy6 single-molecule magnets.