近日，英国曼彻斯特大学David P. Mills团队研究了酰胺-烯烃镝络合物在100开尔文以下的软磁滞。2025年6月25日，《自然》杂志发表了这一成果。

镧系元素在原子和分子水平上都显示出磁记忆。镧系元素单分子磁体的剩磁温度可以超过d-过渡金属的例子，自2017年以来，磁反转的能量势垒（U_eff）从1237（28）cm^-1到1631（25）cm^-1，磁滞回线在40 K和80 K通常是通过轴向镝（III）双（环戊二烯基）配合物实现的。据预测，线性镝（III）化合物可以产生更大的mJ（总角动量J在标记为z的量子化轴上的投影）态分裂，从而产生更高的U_eff和磁滞温度，但由于镧系元素键主要是离子键，到目前为止，镝双（酰胺）配合物显示出高度弯曲的几何形状，促进了快速磁反转。

研究组报道了一种镝双（酰胺）-烯烃络合物[Dy{N（SiⁱPr₃）[Si（ⁱPr）₂C（CH₃）=CHCH₃]}{N（SiⁱPr₃，SiⁱPr₂Et）}][Al{OC（CF₃）₃}₄]（1-Dy），显示U_eff = 1,843(11) cm^-1，软磁滞回线缓慢闭合高达100 K。计算表明，1-Dy的U_eff值来自电荷密集的酰胺配体，其中一个侧链烯烃起着结构作用，以强制执行较大的N-Dy-N角，同时只施加微弱的赤道相互作用。这导致分子自旋动力学比目前90K以上的最佳单分子磁体慢100倍。

附：英文原文

Title: Soft magnetic hysteresis in a dysprosium amide–alkene complex up to 100 kelvin

Author: Emerson-King, Jack, Gransbury, Gemma K., Atkinson, Benjamin E., Blackmore, William J. A., Whitehead, George F. S., Chilton, Nicholas F., Mills, David P.

Issue&Volume: 2025-06-25

Abstract: 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 40K and 80K 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 100K. 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 90K.

DOI: 10.1038/s41586-025-09138-0

Source: https://www.nature.com/articles/s41586-025-09138-0