Soft magnetic hysteresis in a dysprosium amide-alkene complex up to 100 kelvin

• 成果类型: Article
• 署名作者: Emerson-King, Jack; Gransbury, Gemma K.; Atkinson, Benjamin E.; Blackmore, William J. A.; Whitehead, George F. S.; Chilton, Nicholas F.; Mills, David P.
• 署名单位: University of Manchester; Australian National University
• 刊物名称: Nature
• ISSN/ISSBN: 0028-2824
• DOI: 10.1038/s41586-025-09138-0
• 发表日期: 2025-07-03
• 关键词: initio molecular-dynamics; total-energy calculations; transition-metal; basis-sets; single; DESIGN; anisotropy; valence; program; density

摘要

Lanthanides have shown magnetic memory at both the atomic1,2 and molecular3,4 level. The magnetic remanence temperatures of lanthanide single-molecule magnets can surpass d-transition metal examples5,6, and since 2017, energy barriers to magnetic reversal (Ueff) from 1,237(28) cm-1 to 1,631(25) cm-1 and open magnetic hysteresis loops between 40 K and 80 K have typically been achieved with axial dysprosium(III) bis(cyclopentadienyl) complexes7, 8, 9, 10, 11, 12, 13, 14, 15, 16-17. It has been predicted that linear dysprosium(III) compounds could deliver greater mJ (the projection of the total angular momentum, J, on a quantization axis labelled z) state splitting and therefore higher Ueff and hysteresis temperatures18, 19, 20-21, but as lanthanide bonding is predominantly ionic22,23, so far dysprosium bis(amide) complexes have shown highly bent geometries that promote fast magnetic reversal24,25. Here we report a dysprosium bis(amide)-alkene complex, [Dy{N(SiiPr3)[Si(iPr)2C(CH3)=CHCH3]}{N(SiiPr3)(SiiPr2Et)}][Al{OC(CF3)3}4] (1-Dy), that shows Ueff = 1,843(11) cm-1 and slow closing of soft magnetic hysteresis loops up to 100 K. Calculations show that the Ueff value for 1-Dy arises from the charge-dense amide ligands, with a pendant alkene taking a structural role to enforce a large N-Dy-N angle while imposing only a weak equatorial interaction. This leads to molecular spin dynamics up to 100 times slower than the current best single-molecule magnets above 90 K.