【作者】 袁伟； 崔于民； 陶栋梁； 刘少轩； 徐怡庄；

【Author】 Yuan wei~1 Cui Yumin~1 Tao Dongliang~(*,1) Liu Shaoxuan~2 Xu Yizhuang~2 (1 College of Chemisity and Chemical Industry,Fuyang Normal college,Fuyang,236041,China) (2 College of Chemsity and Molecular Engineering,Peking University,Beijing,100871,China)

【机构】 化学与分子工程学院北京大学； 化学化工学院阜阳师范学院；

【摘要】 以邻、间、对溴代苯甲酸（o-BrBA、m-Br BA、p-Br BA）为配体合成了三种溴代苯甲酸铽的稀土配合物Tb（o-Br BA）₃、Tb（m-BrBA）₃、Tb（p-BrBA）₃。用元素分析及红外光谱确定了三种配合物的化学组成。紫外吸收光谱表明,相同摩尔浓度的三种配体及其对应的铽配合物的紫外吸收强度是邻位最强、间位次之、对位最弱,而所对应的铽配合物的荧光强度则恰恰相反,是邻位最弱、间位次之、对位最强。本文从配体的分子结构及配体能级、Tb³⁺的能级、配体到稀土离子之间的能量传递等角度对结果进行了分析。结果表明,由于溴的原子半径较大,溴在苯环上的取代位置的不同所造成的空间位阻作用可能会强烈地影响配位原子与稀土离子的键长。空间位阻越大,配位原子与稀土离子的键长就越长,配体到稀土离子的能量传递效率就越低,从而使得三种邻、间、对溴代苯甲酸的铽配合物具有依次增强的荧光强度。更多还原

【Abstract】 The rare earth complexes Tb（o-BrBA）₃,Tb（m-BrBA）₃ and Tb（p-BrBA）₃ are synthesized using o, m,p-Bromo benzoic acids,respectively.Elemental analysis and IR spectra confirm their chemical composition and coordination of the three complexes,respectively.The UV-spectra showed that the absorption of Tb（o-BrBA）₃ and Tb（m-BrBA）₃ were much stronger than Tb（p-BrBA）₃ with the same molar concentration,and the absorption of Tb（o-BrBA）₃ was the strongest.However,the fluorescent intensity of Tb（p-BrBA）₃ is much stronger than those of Tb（m-BrBA）₃ and Tb（o-BrBA）₃,and the fluorescent intensity of Tb（o-BrBA）₃ is the weakest.In this paper,the structure and the energy level of Tb³⁺and energy transfer efficiency from ligands to Tb³⁺were discussed to explain the experimental results.The results show that, due to the large atomic radius of bromine,bromine substitution in the benzene ring caused by the different location of the steric effects may strongly affect bond length formed by the coordination atoms and rare earth ion.The longer the bond length,the lower the efficiency of energy transfer is.更多还原