中山大学刘俊良团队报道了同位素同构钬单分子磁体的磁化动力学。相关研究成果于2021年10月20日发表在《德国应用化学》。

该文中，研究人员报道了金属结合赤道水分子在报道的具有五角双锥构型的Ho III单分子磁体（SMM）中的氘化，从[Ho(CYPH₂PO)₂(H₂O)₅]³⁺到[Ho(CYPH₂PO)₂(D₂O)₅]³⁺。可以清楚地观察到源自165 Ho III核自旋的超精细结构。此外，由此产生的磁化动力学揭示了两个同位素同构配合物的相对弛豫速率的开关-在低温/高温下更快/慢。

值得注意的是，同位素效应不仅来自顺磁性金属中心，也来自抗磁配体，可以通过从头算计算的隧道分裂和与质子（¹H，I=1/2）和氘的核自旋数差异相关的超精细相互作用来解释（²H，I=1）。

附：英文原文

Title: Magnetization Dynamics on Isotope-Isomorphic Holmium Single-Molecule Magnets

Author: Yang Liu, Le Tuan Anh Ho, Guo-Zhang Huang, Yan-Cong Chen, Liviu Ungur, Jun-Liang Liu, Ming-Liang Tong

Issue&Volume: 2021-10-20

Abstract: Here we reported the deuteration of the metal-binding equatorial water molecules in a reported Ho  III  single-molecule magnet (SMM) with pentagonal-bipyramidal geometry, from [Ho(CyPh  2  PO)  2  (H  2  O)  5  ]  3+  to [Ho(CyPh  2  PO)  2  (D  2  O)  5  ]  3+  . The hyperfine structures originating from the nuclear spin of  165  Ho  III  can be clearly observed. Moreover, the resulting magnetization dynamics revealed the switch of the relative relaxation rates for the two isotope-isomorphic complexes - respectively faster/slower at low/high temperature. The noticeable isotope effect arises from not only the paramagnetic metal center but also the diamagnetic ligands, which can be explained by the  ab initio  calculated tunnel splitting and the involvement of the super-hyperfine interaction related to the difference in the nuclear spin number of protium (  1  H,  I  =  1  /  2  ) and deuterium (  2  H,  I  = 1).

DOI: 10.1002/anie.202112764

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202112764