双核稀土配合物的合成表征及其光学性能(英文)

合成了一种新的双β二酮配体1,4-二苯甲酰乙酰苯(TDAP),并成功合成了它的两个双核稀土配合物Eu2(TDAP)3·(H2O)2和Tb2(TDAP)3·(H2O)6。通过元素分析、红外光谱、紫外可见光谱和荧光光谱对配合物进行了表征与性能研究。荧光分析表明,在紫外灯下配体本身就发出蓝紫色荧光,通过对配体TDAP的磷光光谱分析计算得到了配体的平均三重态能级。配合物Eu2(TDAP)3·(H2O)2的发射光谱分析表明,配体自身的发射几乎完全被淬灭,能量成功传递给了中心离子,因此配合物发出了明显的特征峰,主发射峰为Eu3+的5D0-7F2发射。由荧光分析知,配合物Eu2(TDAP)3·(H2O)2的激发光谱与配体发射光谱的重叠,这验证了配体TDAP对于Eu3+能量传递的有效性。此外,还详细分析了两种配合物的能量传递过程及发光机理,配合物Tb2(TDAP)3·(H2O)6几乎不发光,这是因为配体的三重态能级与Tb3+的最低激发态能级不匹配。合成的配合物Eu2(TDAP)3·(H2O)2有很强荧光,是一种有效的红色发光材料。

Synthesis, Characterization and Luminescence Properties of Dinuclear Lanthanide Complexes

Two new complexes of Eu(Ⅲ) and Tb(Ⅲ) chelated with bis(β-diketone) terephthaloyl-diacetophenone (TDAP) were successfully synthesized. The samples were characterized by the element analysis, infrared spectra, UV-Vis spectra, 1H NMR and fluorescence spectra. The results indicated that their compositions are Eu2(TDAP)3· (H2O)2 and Tb2 (TDAP)3 · (H2O)6, respectively. Photoluminescence measurement indicated that TDAP is a good indigo emitter under UV radiation. The average triplet state energy of the ligand was obtained by analyzing the phos-phorescence spectrum of TDAP. The Eu(Ⅲ) complexes display characteristic metal-centered luminescence, while the ligand emissions are completely quenched. The results indicated that the efficient ligand-to-metal energy transfer (antenna effect) occurs. The characteristic red emission appears due to the 5D0 → 7Fj transitions of the 4f electrons of the central Eu3+ ions. Tb2(TDAP)3 ·(H2O)6 has poor fluorescence property, this is because the triplet state energy of the ligand does not match with the lowest excited state energy of Tb3+ ions. The possible energy transfer mechanism was investigated.