Jiangsu Key Lab for NSLSCS, School of Physical Science and Technology, Nanjing Normal University, Nanjing 210023, P. R. China.
J Phys Chem A. 2023 Apr 13;127(14):3088-3095. doi: 10.1021/acs.jpca.2c08526. Epub 2023 Mar 29.
Theoretical investigations on mixed-valence dilanthanide complexes (Cp)LnI (Ln = Tb, Dy, and Ho) indicate that the total spin of the 4f shell couples preferentially to the σ electron spin and then to the orbital angular momentum, improving the strength of spin-orbit coupling (SOC) for each magnetic center. On the other hand, the concentration of negative charges containing the delocalized σ electron in the axial direction leads to a large crystal-field (CF) splitting. Both strong SOC and large CF splitting lead to the largest energy barrier of such complexes up to now. In addition, our calculations show that the introduction of σ electron can better suppress the quantum tunneling of magnetization in the ground spin-orbit state, and the of (Cp)LnI is expected to originate from the contribution of both Ln ions under such strong Ln-σ exchange coupling.
理论研究表明，混合价镧系元素配合物（Cp）LnI（Ln = Tb、Dy 和 Ho）中，4f 壳层的总自旋优先与σ电子自旋耦合，然后与轨道角动量耦合，从而增强每个磁中心的自旋轨道耦合（SOC）强度。另一方面，轴向含有离域σ电子的负电荷浓度导致大的晶体场（CF）分裂。强 SOC 和大 CF 分裂导致这些配合物迄今为止具有最大的能垒。此外，我们的计算表明，σ电子的引入可以更好地抑制基态自旋轨道态下的磁量子隧穿，（Cp）LnI 的弛豫率预计源于在这种强 Ln-σ 交换耦合作用下，Ln 离子的共同贡献。
