Syntheses, Structures, Near-Infrared and Visible Luminescence, and Magnetic Properties of Lanthanide-Organic Frameworks with an Imidazole-Containing Flexible Ligand
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- 作者：Zheng-Hua Zhang ; You Song ; Taka-aki Okamura ; Yasuchika Hasegawa ; Wei-Yin Sun ; and Norikazu Ueyama
- 刊名：Inorganic Chemistry
- 出版年：2006
- 出版时间：April 3, 2006
- 年：2006
- 卷：45
- 期：7
- 页码：2896 - 2902
- 全文大小：175K
- 年卷期：v.45,no.7(April 3, 2006)
- ISSN：1520-510X
文摘
Reactions of tripodal ligand 1,3,5-tris(imidazole-1-ylmethyl)-2,4,6-trimethylbenzene (L) with lanthanide metal saltsand triethyl orthoformate led to the formation of six bowl-like dinuclear compounds [Ln2(L)(HL)(NO3)6(HCOO)]·3CH3OH (Ln = Gd 1, Tb 2, Dy 3, Er 4, Yb 5, and Eu 6). The single-crystal X-ray diffraction analysis revealed thatsix complexes are isomorphous and isostructural and that the dinuclear molecules are further connected by hydrogenbonds and 
- interactions, resulting in 3D channel-like structures. The luminescence properties have been studied,and the results showed that the Tb(III) (2) and Eu(III) (6) complexes exhibited sensitized luminescence in thevisible region and their luminescence lifetimes in powder and DMSO-d6 solution are in the range of milliseconds.The Yb(III) complex (5) emits typical near-infrared luminescence in DMSO-d6 solution. Variable-temperature magneticsusceptibility measurements of 1-6 showed that complex 1 (Gd) is nearly a paramagnet and complexes 2 (Tb),3 (Dy), and 4 (Er) show the ferromagnetic coupling between magnetic centers, whereas the depopulation of theStark levels in complexes 5 (Yb) and 6 (Eu) leads to a continuous decrease in 
MT when the sample is cooledfrom 300 to 1.8 K.
- interactions, resulting in 3D channel-like structures. The luminescence properties have been studied,and the results showed that the Tb(III) (2) and Eu(III) (6) complexes exhibited sensitized luminescence in thevisible region and their luminescence lifetimes in powder and DMSO-d6 solution are in the range of milliseconds.The Yb(III) complex (5) emits typical near-infrared luminescence in DMSO-d6 solution. Variable-temperature magneticsusceptibility measurements of 1-6 showed that complex 1 (Gd) is nearly a paramagnet and complexes 2 (Tb),3 (Dy), and 4 (Er) show the ferromagnetic coupling between magnetic centers, whereas the depopulation of theStark levels in complexes 5 (Yb) and 6 (Eu) leads to a continuous decrease in MT when the sample is cooledfrom 300 to 1.8 K.