From a Piano Stool to a Sandwich: A Stepwise Route for Improving the Slow Magnetic Relaxation Properties of Thulium
journal contributionposted on 29.08.2017 by Katie L. M. Harriman, Ilia Korobkov, Muralee Murugesu
Any type of content formally published in an academic journal, usually following a peer-review process.
Two mononuclear TmIII complexes, [Tm(COT)I(THF)2] (1-Tm) and [K(18-crown-6)(THF)2][Tm(COT)2] (2-Tm), display slow relaxation of the magnetization, making these compounds rare examples of non-Kramers TmIII single-molecule magnets (SMMs). Utilizing a stepwise synthetic approach for the installation of cyclooctatetraenide (COT) ligands, we can observe the effect of symmetry optimization at the metal center. This method results in an 85% increase in the energy barrier to magnetization reversal (Ueff) for 2-Tm (Ueff = 53.3 K) over 1-Tm (Ueff = 7.93 K). The increased local symmetry of 2-Tm reduces the need for large static fields, eliciting SMM behavior under a small field of 200 Oe. This illustrates the power of fine-tuning the ligand environment to enhance the magnetic relaxation properties of non-Kramers ions.