Synthesis, crystal structure and fluorescence of a new europium complex with 2-bromobenzoate and 2,2′-bipyridine

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• 作者：Xiao QIU ; Yanbin ZHANG ; Xia LI
• 关键词：europium complex ; 2-bromobenzoic acid ; crystal structure ; fluorescence ; rare earths
• 刊名：Journal of Rare Earths
• 出版年：2009
• 出版时间：October 2009
• 年：2009
• 卷：27
• 期：5
• 页码：797-800
• 全文大小：416 K

文摘

A new complex of {[Eu₂(2-BrBA)₆(2,2′-bpy)₂]₂·CH₃CH₂OH·H₂O} (2-BrBA=2-bromobenzoate; 2,2′-bpy=2,2′-bipyridine) was prepared by solvent method and characterized with X-ray single-crystal diffraction, IR spectroscopy, UV spectroscopy, and fluorescence spectroscopy. The complex crystallized in triclinic crystal system, Pī space group, with a=1.17196(4) nm, b=2.36142(9) nm, c=2.59151(9) nm, α=113.266(2)°, β=101.100(2)°, and γ=94.400(2)°. Two independent dinuclear molecules were contained in the asymmetric unit. The two molecules were similar to each other. Each Eu(III) ion was nine-coordinated with seven oxygen atoms from five 2-BrBA ligands and two nitrogen atoms from 2,2′-bpy molecule. The carboxylate groups acted as bidentate-chelating, bidentate-bridging and chelating-bridging coordination modes. The complex adopted a distorted monocapped square-antiprism coordination geometry. Five peaks at 579, 591, 613, 652, and 697 nm appeared in the fluorescence spectrum, corresponding to ⁵D₀→⁷F₀, ⁵D₀→⁷F₁, ⁵D₀→⁷F₂, ⁵D₀→⁷F₃, and ⁵D₀→⁷F₄ transition emissions of the Eu(III) ion, respectively.