From a Piano Stool to a Sandwich: A Stepwise Route for Improving the Slow Magnetic Relaxation Properties of Thulium
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 installa...
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Published in | Organometallics Vol. 36; no. 23; pp. 4515 - 4518 |
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Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
American Chemical Society
11.12.2017
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Online Access | Get full text |
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Summary: | 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 (U eff) for 2-Tm (U eff = 53.3 K) over 1-Tm (U eff = 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. |
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ISSN: | 0276-7333 1520-6041 |
DOI: | 10.1021/acs.organomet.7b00449 |