Ge Jing-Yuan, Qiu Ya-Ru, Wang Hai-Ying, Su Jian, Wang Peng, Chen Zhongyan
College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou, 325035, China.
State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023, China.
Chem Asian J. 2020 Oct 1;15(19):3013-3019. doi: 10.1002/asia.202000655. Epub 2020 Aug 27.
It is crucial to investigate the slow relaxation mechanisms of binuclear Er -based single-molecule magnets (SMMs) and explore strategies for optimizing their magnetic properties. Herein, a doped compound, [Y Er (thd) Pc] ⋅ 2C H (YEr ⋅ 2C H , Hthd=2,2,6,6-tetramethylheptanedione, H Pc=phthalocyanine), was synthesized by doping the paramagnetic erbium(III) compound Er ⋅ 2C H in the diamagnetic yttrium(III) matrix Y ⋅ 2C H . The doping effect was studied using SQUID magnetization measurements. The results suggest that magnetic-site dilution improves the magnetic property from a fast relaxation of the pure Er compound to a typical SMM relaxation process of the doped sample. In this binuclear system, the dominant single-ion relaxation is entangled with the neighboring Er ion through the intramolecular Er ⋅⋅⋅Er interaction, which plays an important role in suppressing the quantum tunneling of the magnetization (QTM) process. Furthermore, the influence of lattice solvents on single-ion relaxation was studied. By releasing the benzene molecules, compound YEr ⋅ 2C H can be successfully transformed to a desolvated sample YEr accompanied by structural alteration and improved SMM performance.
研究双核铒基单分子磁体（SMMs）的慢弛豫机制并探索优化其磁性能的策略至关重要。在此，通过将顺磁性铒（III）化合物Er₂·2C₆H₆掺杂到抗磁性钇（III）基体Y₂·2C₆H₆中，合成了一种掺杂化合物[YEr(thd)Pc]·2C₆H₆（YEr·2C₆H₆，Hthd = 2,2,6,6 - 四甲基庚二酮，HPc = 酞菁）。使用超导量子干涉仪（SQUID）磁化测量研究了掺杂效应。结果表明，磁位点稀释将磁性能从纯Er化合物的快速弛豫改善为掺杂样品的典型SMM弛豫过程。在这个双核体系中，主要的单离子弛豫通过分子内Er···Er相互作用与相邻的Er离子纠缠在一起，这在抑制磁化量子隧穿（QTM）过程中起着重要作用。此外，还研究了晶格溶剂对单离子弛豫的影响。通过释放苯分子，化合物YEr·2C₆H₆可以成功转化为去溶剂化样品YEr，同时伴随着结构变化和SMM性能的改善。
