Probing Relaxation Dynamics in Five‐Coordinate Dysprosium Single‐Molecule Magnets
Vijay S. Parmar, Fabrizio Ortu, Xiaozhou Ma, Nicholas F. Chilton, Rodolphe Clérac, David P. Mills, Richard E. P. Winpenny
Abstract
Abstract A new family of five‐coordinate lanthanide single‐molecule magnets (Ln SMMs) [Dy(Mes*O) 2 (THF) 2 X] (Mes*=2,4,6‐tri‐tert‐butylphenyl; X=Cl, 1 ; Br, 2 ; I, 3 ) is reported with energy barriers to magnetic reversal >1200 K. The five‐coordinate Dy III ions have distorted square pyramidal geometries, with halide anions on the apex, and two Mes*O ligands mutually trans ‐ to each other, and the two THF molecules forming the second trans ‐ pair. These geometrical features lead to a large magnetic anisotropy in these complexes along the trans ‐Mes*O direction. QTM and Raman relaxation times are enhanced by varying the apex halide from Cl to Br to I, or by dilution in a diamagnetic yttrium analogue.