Ultrahard magnetism from mixed-valence dilanthanide complexes with metal-metal bonding
Ultrahard magnetism from mixed-valence dilanthanide complexes with metal-metal bonding
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DOI：
10.1126/science.abl5470
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发表时间：
2022-01-14
期刊：
影响因子：
56.9
通讯作者：
Long, Jeffrey R.
中科院分区：
文献类型：
--
作者：
Gould, Colin A.;McClain, K. Randall;Long, Jeffrey R.
金属-金属成键相互作用可以在块体材料和分子中产生突出的磁性，过渡金属的例子比比皆是。将这一范例扩展到镧系元素，本文中我们报道了混合价二镧系元素配合物（Cp-iPr 5）（2）Ln（2）I（3）（Ln是Gd、Tb或Dy; Cp-iPr 5，五异丙基钕），其特征在于通过结构、光谱和计算分析确定的5d（z2）母体的单一占据的镧系元素-镧系元素σ键轨道。价离域，其中d电子由两个镧系元素中心均等地共享，根据Hund规则赋予两个镧系元素上的σ键和f电子的强平行排列。在（Cp-iPr 5）（2）Dy 2 I3中，高自旋基态和大的磁各向异性相结合，在高达60开尔文的温度下产生了下限为14特斯拉的巨大矫顽磁场。
Metal-metal bonding interactions can engender outstanding magnetic properties in bulk materials and molecules, and examples abound for the transition metals. Extending this paradigm to the lanthanides, herein we report mixed-valence dilanthanide complexes (Cp-iPr5)(2)Ln(2)I(3) (Ln is Gd, Tb, or Dy; Cp-iPr5, pentaisopropylcyclopentadienyl), which feature a singly occupied lanthanide-lanthanide sigma-bonding orbital of 5d(z2) parentage, as determined by structural, spectroscopic, and computational analyses. Valence delocalization, wherein the d electron is equally shared by the two lanthanide centers, imparts strong parallel alignment of the sigma-bonding and f electrons on both lanthanides according to Hund's rules. The combination of a well-isolated high-spin ground state and large magnetic anisotropy in (Cp-iPr5)(2)Dy2I3 gives rise to an enormous coercive magnetic field with a lower bound of 14 tesla at temperatures as high as 60 kelvin.