Tuning the Coordination Geometries and Magnetic Dynamics of [Ln(hfac)4]? through Alkali Metal Counterions

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• 作者：Dai Zeng ; Min Ren ; Song-Song Bao ; Li-Min Zheng
• 刊名：Inorganic Chemistry
• 出版年：2014
• 出版时间：January 21, 2014
• 年：2014
• 卷：53
• 期：2
• 页码：795-801
• 全文大小：496K
• ISSN：1520-510X

文摘

Four lanthanide compounds with formulas [Cs{Dy(hfac)₄}] (1), [Cs{Er(hfac)₄}] (2), [K{Dy(hfac)₄}] (3), and [K{Er(hfac)₄}] (4) (hfac = hexafluoroacetylacetone) are reported. Compounds 1 and 2 crystallize in the orthorhombic Pbcn space group, while 3 and 4 are in the triclinic P1̅ space group. All display chain structures in which the mononuclear [Ln(hfac)₄]^{鈭?/sup> anions are linked by alkali metal ions. However, the coordination geometries around the Ln atoms are quite different depending on the cation. They adopt a distorted dodecahedron with pseudo-D_2d symmetry in the cesium compounds 1 and 2, while a distorted square-antiprism with pseudo-D_4d symmetry is adopted in the potassium compounds 3 and 4. The latter compounds show distinct field-induced slow magnetization relaxation. The energy barriers are 23.95 and 20.21 K for compounds 3 and 4, respectively.}