Hexanuclear [Cp*Dy]6 single-molecule magnet

Abstract

A hexanuclear cluster containing six {Cp*Dy} units shows a high energy barrier ( U eff = 561 K) for magnetic relaxation and butterfly-shaped hysteresis loops up to 4.5 K.

A hexanuclear cluster [(Cp*Dy) 6 K 4 Cl 16 (THF) 6 ], [Cp*Dy]6 , has been constructed from six {Cp*Dy III } 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.