双核铕与2,5-二氟苯甲酸及2,2′-联吡啶配合物的合成、晶体结构及表征

Synthesis,Crystal Structure and Characterization of a Binuclear Europium 2,5-difluorobenzoic Acid Complex with 2,2'-bipyridine

用溶液法合成了混配配合物[Eu(2,5-DFBA)3(2,2′-bipy)]2(2,5-DFBA=2,5-二氟苯甲酸根,2,2′-bipy=2,2′-联吡啶),并测定了其晶体结构。该晶体属于三斜晶系,P1空间群。在配合物中,2个Eu3+离子被4个2,5-二氟苯甲酸根以双齿桥联和三齿桥联2种方式连接;每个Eu3+离子的配位数为9,分别与4个桥联2,5-二氟苯甲酸根的5个氧原子、1个双齿螯合2,5-二氟苯甲酸根的2个氧原子以及1个2,2′-联吡啶分子的2个氮原子配位。该配合物在紫外灯照射下发出强烈的红光,在荧光光谱的580、591、613、648和693nm处出现5条谱线,分别是由Eu3+离子的5D0→7Fj(j=0～4)跃迁产生的。

[Eu（2,5-DFBA）3（2,2′-bipy）]2 （2,5-DFBA=2,5-Difluorobenzoate, 2,2′-bipy=2,2′-bipyridine） has been obtained by solvent method and characterized by X-ray diffraction single-crystal structure analysis. The complex crystallizes in Triclinie system, P1 space group with a= 1.137 2（2）nm, b=1.222 7（2） nm, c=1.263 7（3）nm, α= 104.17（3）°,/3=103.08（3）°, T=113.61（3）°. In the complex, two Eu^3＋ ions are linked by four 2,5-DFBA ligands in bridging-bidentate and bridging-chelating coordination modes. Each Eu^3＋ ion is nine-coordinated to five oxygen atoms of four bridge 2,5-DFBA ligands, two oxygen atoms of one chelating-bidentate 2,5-DFBA ligand, two nitrogen atoms of one 2,2′-bipy molecule. The complex exhibits strong red fluorescence under ultraviolet light. The fluorescence spectrum has five peaks at 580, 591,613, 648 and 693 nm, which caused by 5D0→7Fj（j=0～4） transitions of Eu^3＋ ion. CCDC： 675498.