中山大学童明良团队报道了具有多钼酸盐可逆氧化还原转化的光致变色镝单分子磁铁。相关研究成果发表在2024年12月12日出版的国际学术期刊《德国应用化学》。

通过聚钼酸根阴离子和伊辛型阳离子的共晶工程，合成了一种光致变色镝基单分子磁体[[Dy(CyPh₂PO)₂(H₂O)₅](PMo₁₂O₄₀)·3CyPh₂PO·H₂O (1-Dy)，其具有伪五边形双锥结构。在紫外线照射下，POMo部分发生从MoVI到MoV的单电子光还原，导致光学和磁性发生显著变化。

杂多蓝态1-Dy*中出现的间光电荷转移跃迁促进了近红外区域的光热转换。同时，在2 K下，磁滞回线的矫顽场从0.72 T（1-Dy）变为0.04 T（1-Dy*），这可能是由于DyIII和MoV之间的磁相互作用所致。经过暗处理后，1-Dy*可以转化为初始状态，恢复磁记忆效应。

该文提出的这些结果为通过光化学调节和磁相互作用的耦合，开发多功能光磁材料提供了蓝图。

附：英文原文

Title: Photochromic Dysprosium Single-Molecule Magnet Featuring Reversible Redox Transformation of Polyoxomolybdate Moiet

Author: Hui Kong, Jing-Yu Wang, Jia-Chuan Liu, Lu Zhang, Pei-Yu Liao, Yu-Quan Qi, Zheng Liu, Si-Guo Wu, Ming-Liang Tong

Issue&Volume: 2024-12-12

Abstract: A photochromic dysprosium-based single-molecule magnet [Dy(CyPh2PO)2(H2O)5](PMo12O40)·3CyPh2PO·H2O (1-Dy) is synthesized via cocrystal engineering of a polyoxomolybdate (POMo) anion and an Ising-type cation with pseudo pentagonal bipyramidal geometry. Upon ultraviolet irradiation, MoVI-to-MoV single-electron photoreduction occurs in the POMo moiety, resulting in significant changes of optical and magnetic properties. The emergence of intervalence charge-transfer transitions in heteropoly blue state 1-Dy* facilitates photothermal conversion in near-infrared region. Meanwhile, the coercive field of hysteresis loop is altered from 0.72 T (1-Dy) to 0.04 T (1-Dy*) at 2 K, which might be contributed to the magnetic interaction between DyIII and MoV. After dark treatment, 1-Dy* can convert to the initial state with the recovery of magnetic memory effect. These results presented herein provide a blueprint for developing versatile opto-magnetic materials via the coupling of photochemical regulation and magnetic interaction.

DOI: 10.1002/anie.202422557

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202422557