A delocalized arene-bridged diuranium single-molecule magnet
A delocalized arene-bridged diuranium single-molecule magnet
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DOI：
10.1038/nchem.1028
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发表时间：
2011-06-01
期刊：
影响因子：
21.8
通讯作者：
Liddle, Stephen T.
中科院分区：
文献类型：
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作者：
Mills, David P.;Moro, Fabrizio;Liddle, Stephen T.
单分子磁体（SMM）是在阻断温度以下表现出纯粹分子起源的稳定磁化的化合物，而不是由体中磁矩的长程有序引起的。因此，它们显示出超高密度数据存储等应用的前景。磁化强度的稳定性随着基态自旋和磁各向异性的增加而增加。过渡金属SMM通常具有高自旋基态，但磁各向异性不足。镧系SMM表现出大的磁各向异性，但是构建高自旋基态是困难的，因为它们倾向于形成限制磁交换耦合的离子键。相比之下，与铀相关的显著共价键合和大自旋轨道贡献对于改进的SMM的开发特别有吸引力。在这里，我们报告了一个离域芳烃桥联双铀SMM。这项研究表明，芳烃桥接的多铀团簇可以表现出SMM行为，而不依赖于自旋的超交换耦合。这种方法可能导致阻塞温度升高。
Single-molecule magnets (SMMs) are compounds that, below a blocking temperature, exhibit stable magnetization purely of molecular origin, and not caused by long-range ordering of magnetic moments in the bulk. They thus show promise for applications such as data storage of ultra-high density. The stability of the magnetization increases with increasing ground-state spin and magnetic anisotropy. Transition-metal SMMs typically possess high-spin ground states, but insufficient magnetic anisotropies. Lanthanide SMMs exhibit large magnetic anisotropies, but building high-spin ground states is difficult because they tend to form ionic bonds that limit magnetic exchange coupling. In contrast, the significant covalent bonding and large spin-orbit contributions associated with uranium are particularly attractive for the development of improved SMMs. Here we report a delocalized arene-bridged diuranium SMM. This study demonstrates that arene-bridged polyuranium clusters can exhibit SMM behaviour without relying on the superexchange coupling of spins. This approach may lead to increased blocking temperatures.