1. Rare CH3O−/CH3CH2O−-bridged nine-coordinated binuclear DyIII single-molecule magnets (SMMs) significantly regulate and enhance the effective energy barriers.
- Author
-
Zhang, Sheng, Shen, Nan, Liu, Sha, Ma, Rong, Zhang, Yi-Quan, Hu, Deng-Wei, Liu, Xiang-Yu, Zhang, Jiang-Wei, and Yang, De-Suo
- Subjects
ACTIVATION energy ,MAGNETIC anisotropy ,MAGNETS ,MAGNETIC relaxation ,HYSTERESIS loop ,IONS - Abstract
Based on a multidentate Schiff-base ligand, N,N′-bis(2-hydroxy-5-methyl-3-formylbenzyl)-N,N′-bis-(pyridin-2-ylmethyl)ethylenediamine (H
2 L), two binuclear DyIII compounds, with formulas [Dy2 (L)(NO3 )3 (CH3 O)] (1) and [Dy2 (L)(NO3 )3 (CH3 CH2 O)] (2), have been synthesized under different solvent systems. The DyIII ions in 1 and 2 adopt monocapped square antiprism coordination geometries, while different structural distortions can be observed. The two DyIII ions in 1 and 2 are bridged by two phenoxide atoms of one L2− ligand and one bridged CH3 O− /CH3 CH2 O− oxygen node, leading to an approximate fusiform Dy2 O3 core. The different DyIII –Obridged node distances, DyIII –Obridged node –DyIII angles and DyIII ⋯DyIII distances can be observed. Magnetic studies reveal that 1 and 2 display slow magnetic relaxation behaviours under a zero direct-current field with the effective energy barriers (Ueff ) of 114.17 K and 171.23 K, respectively. Furthermore, compound 2 possesses the highest Ueff in nine-coordinated Dy2 compounds. The M versus H data exhibit weak butterfly-shaped hysteresis loops at 2 K for 2. The rare CH3 O− /CH3 CH2 O− -bridged nine-coordinated binuclear DyIII single-molecule magnets (SMMs) significantly regulate and enhance the Ueff of compounds 1 and 2. To deeply understand their different magnetic behaviours, the magnetic anisotropies and magnetic interactions of 1 and 2 were studied by ab initio calculations. These findings demonstrate an efficient approach for regulating and enhancing the magnetic anisotropy barriers using a bridged CH3 O− anion or CH3 CH2 O− anion. [ABSTRACT FROM AUTHOR]- Published
- 2020
- Full Text
- View/download PDF