Slow Magnetic Relaxation and Single‐Molecule Toroidal Behaviour in a Family of Heptanuclear {Cr^IIILn^III₆} (Ln=Tb, Ho, Er) Complexes

Abstract

The synthesis, magnetic properties, and theoretical studies of three heterometallic {Cr^III Ln^III₆ } (Ln=Tb, Ho, Er) complexes, each containing a metal topology consisting of two Ln₃ triangles connected via a Cr^III linker, are reported. The {CrTb₆ } and {CrEr₆ } analogues display slow relaxation of magnetization in a 3000 Oe static magnetic field. Single-crystal measurements reveal opening up of the hysteresis loop for {CrTb₆ } and {CrHo₆ } molecules at low temperatures. Ab initio calculations predict toroidal magnetic moments in the two Ln₃ triangles, which are found to couple, stabilizing a con-rotating ferrotoroidal ground state in Tb and Ho examples and extend the possibility of observing toroidal behaviour in non Dy^III complexes for the first time.