Hexanuclear [Cp∗Dy]6 single-molecule magnet

Abstract

A hexanuclear cluster [(Cp∗Dy)6K4Cl16(THF)6], [Cp∗Dy]6, has been constructed from six {Cp∗DyIII} synthons in which the strongly coordinating Cp∗- caps determine the local anisotropy axes. Structural characterization of [Cp∗Dy]6 shows two almost parallel triangular (Cp∗Dy)3 fragments that are linked by the K+ and Cl- ions. Magnetic measurements reveal slow thermal relaxation and fast quantum tunneling relaxation in the absence of an external dc field. After applying a weak dc field, the quantum tunneling relaxation is efficiently suppressed, giving a sizable energy barrier of 561 K, which represents the current record energy barrier for high nuclearity organometallic SMMs.