稀土(铕、铽)芳香羧酸配合物的荧光性能研究

Fluorescence Properties of Rare Earth(Eu-Tb) Complexes with Aromatic Carboxylic Acid Ligand

以4-正戊基苯甲酸(PBA)为第一配体,2,2′-联吡啶(bipy)为第二配体,合成了铕、铽的三元配合物,EuxTb(1-x)(PBA)3bipy(x=1.0,0.7,0.5,0.3,0.0).并通过UV、IR、元素分析和稀土络合滴定对其结构进行了表征.用荧光分光光度计研究了配合物的荧光性能以及Eu3+、Tb3+之间的荧光性能的互相影响规律.实验结果表明,在稀土(铕、铽)荧光配合物中,Eu3+与Tb3+之间的荧光有相互敏化或猝灭作用.其中在n(Eu3+)∶n(Tb3+)=7∶3或3∶7时,Tb3+对Eu3+的荧光有猝灭作用,而在n(Eu3+)∶n(Tb3+)=1∶1时,Tb3+对Eu3+的荧光有敏化作用;Eu3+对Tb3+的荧光有很强的荧光猝灭作用,且猝灭作用随铕离子浓度的增大明显增强.

In this study,the ternary rare earth（Eu-Tb） complexes,EuxTb（1-x）（PBA）3bipy（x=1.0,0.7,0.5,0.3,0.0） were synthesized using 4-pentylbenzoic acid（PBA） as the first ligand and 2,2′-bipyridine（bipy） as a secondary ligand.The complexes were characterized by means of elemental analysis,rare earth coordination titration,ultraviolet and infrared spectroscopies.Their fluorescence properties and the mutual effect on the fluorescence properties of europium and terbium were investigated via the fluorescence spectroscopy.The results show that the fluorescent intensity has a sensitization or quenching effect between Eu3＋ and Tb3＋ in the rare-earth（Eu3＋,Tb3＋） fluorescence complexes.When n（Eu3＋） ∶n（Tb3＋） is 7 ∶3 or 3 ∶7,Tb3＋ ions show a luminescence quenching effect on Eu3＋ ions.But when n（Eu3＋） ∶n（Tb3＋） is 1 ∶1,Tb3＋ ions exhibit a luminescence sensitization effect on Eu3＋ ions.In addition,Eu3＋ ions display a luminescence quenching effect on Tb3＋ ions and the quenching effect is stronger with the increase of Eu3＋ concentration.