Zhu Li, Dong Yubao, Yin Bing, Ma Pengtao, Li Dongfeng
Key Laboratory of Pesticide & Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079, P. R. China.
Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an 710127, P. R. China.
Dalton Trans. 2021 Sep 21;50(36):12607-12618. doi: 10.1039/d1dt00964h.
Two mononuclear Dy compounds [Dy(bmbpen-F)X] (X = Cl, 1; Br, 2) with a pentagonal bipyramidal (PBP) geometry were obtained from ,'-bis-(5-methyl-2-hydroxybenzyl)-,'-bis(5-fluoro-2-methylpyridyl)ethylenediamine (Hbmbpen-F) and dysprosium halides. The magnetic anisotropy and single-molecule magnet (SMM) behavior of these PBP compounds were regulated by introducing both electron-withdrawing F atoms into the equatorial pyridine rings and electron-donating -CH groups into the axial phenolic hydroxyl rings. The results of magnetic characterization show that 1 and 2 exhibit single molecule magnet behavior with magnetization reversal barriers of 990(13) and 1189(16) K under a zero dc external field and magnetic hysteresis loops up to 26 K and 36 K, respectively. The results of calculations are consistent with the experimental observations, confirming that the simultaneous introduction of electron-withdrawing groups into the equatorial positions and electron-donating groups into the axial positions can lead to PBP Dy-SMMs with improved properties.
通过(α,α'-双-(5-甲基-2-羟基苄基)-α,α'-双(5-氟-2-甲基吡啶基)乙二胺(Hbmbpen-F))与卤化镝反应，得到了两种具有五角双锥(PBP)几何构型的单核镝化合物([Dy(bmbpen-F)X])（(X = Cl)，1；(Br)，2）。通过将吸电子的(F)原子引入赤道面吡啶环以及将供电子的(-CH)基团引入轴向酚羟基环，对这些PBP化合物的磁各向异性和单分子磁体(SMM)行为进行了调控。磁性表征结果表明，1和2在零直流外场下表现出单分子磁体行为，其磁化反转势垒分别为990(13)和1189(16)K，磁滞回线分别高达26K和36K。计算结果与实验观察结果一致，证实了在赤道位置同时引入吸电子基团和在轴向位置引入供电子基团可导致性能得到改善的PBP Dy-SMMs。
