Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog Weg 1-5/10, 8093 Zürich, Switzerland.
Univ Rennes CNRS, ISCR (Institut des Sciences Chimiques de Rennes), UMR 6226, 35000 Rennes, France.
J Am Chem Soc. 2023 Jun 14;145(23):12446-12451. doi: 10.1021/jacs.3c02730. Epub 2023 Jun 1.
Generating or even retaining slow magnetic relaxation in surface immobilized single-molecule magnets (SMMs) from promising molecular precursors remains a great challenge. Illustrative examples are organolanthanide compounds that show promising SMM properties in molecular systems, though surface immobilization generally diminishes their magnetic performance. Here, we show how tailored Lewis acidic Al(III) sites on a silica surface enable generation of a material with SMM characteristics via chemisorption of (Cp)DyCl ((Cp) = 1,2,4-tri(-butyl)-cyclopentadienide). Detailed studies of this system and its diamagnetic Y analogue indicate that the interaction of the metal chloride with surface Al sites results in a change of the coordination sphere around the metal center inducing for the dysprosium-containing material slow magnetic relaxation up to 51 K with hysteresis up to 8 K and an effective energy barrier () of 449 cm, the highest reported thus far for a supported SMM.
在表面固定的单分子磁体（SMM）中产生甚至保留慢磁弛豫仍然是一个巨大的挑战。有前景的分子前体，如有机镧系化合物，在分子体系中表现出有前景的 SMM 特性，但表面固定通常会降低它们的磁性能。在这里，我们展示了如何通过在二氧化硅表面上的定制路易斯酸性 Al（III）位点，通过（Cp）DyCl（Cp = 1,2,4-三（- 丁基）-环戊二烯基）的化学吸附，产生具有 SMM 特性的材料。对该体系及其反磁性 Y 类似物的详细研究表明，金属氯化物与表面 Al 位点的相互作用导致金属中心周围的配位球发生变化，从而使含镝的材料在 51 K 下具有慢磁弛豫，磁滞高达 8 K，有效能垒（）为 449 cm，这是迄今为止报道的最高值，用于支持 SMM。
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