Local Coordination Geometry Perturbed 尾-Diketone Dysprosium Single-Ion Magnets
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- 作者：Jing Zhu ; Changzheng Wang ; Fang Luan ; Tianqi Liu ; Pengfei Yan ; Guangming Li
- 刊名：Inorganic Chemistry
- 出版年：2014
- 出版时间：September 2, 2014
- 年：2014
- 卷：53
- 期：17
- 页码：8895-8901
- 全文大小：464K
- ISSN：1520-510X
文摘
A series of three 尾-diketone mononuclear dysprosium complexes, namely, Dy(TFI)3(H2O)2 (1), Dy(TFI)3(bpy) (2), and [Dy(TFI)3(Phen)]路0.02CHCl3 (3) (TFI = 2-(2,2,2-trifluoroethyl)-1-indone, bpy = 2,2鈥?bipyridine, phen = 1,10-phenanthroline) have been designed and synthesized. Crystal structure analysis reveals that complexes 1鈥?b>3 have haveisomorphic structures in which the central Dy(III) ion is eight-coordinated by six oxygen atoms from three TFI ligands and two O/N atoms from auxiliary ligands, forming a distorted bicapped trigonal prismatic geometry for 1, a distorted dodecahedral geometry for 2, and a distorted square antiprismatic geometry for 3, respectively. Magnetic studies indicate that complex 2 with D2d symmetry and 3 with D4d symmetry exhibit slow magnetic relaxation with barrier heights (Ueff/kB) of 48.8 K for 2 and 57.9 K for 3. Strikingly, the relaxation time (蟿) of 0.0258 s for 3 is about 20 times that for 2, which is presumably associated with larger rotation of the SAP surroundings for 3. Further, complexes 2 and 3 exhibit essential magnetic hysteresis loops at 1.8 K. These extend the recent reports of the single-ion magnets (SIMs) of 尾-diketone mononuclear dysprosium complexes.