1，6-二[(2′-苄胺甲酰基)苯甲氧基]己烷混合稀土配合物中镧、钆、钇对铕和铽荧光性能的影响

Influence of La^(3+) Gd^(3+) and Y^(3+) on Fluorescence of Eu and Tb Complexes with 1,6-bis[(2′-benzylaminoformyl) phenoxyl]hexane

在氯仿和乙酸乙酯溶液中合成了1,6-二[(2′-苄胺甲酰基)苯甲氧基]己烷(L)的铕和铽的配合物,及其与La(Ⅲ)、Gd(Ⅲ)、Y(Ⅲ)的混合配合物。元素分析数据表明单—稀土硝酸盐与配体形成的是2:3型的配合物;通过红外光谱表征,混合配合物和单一配合物具有相似的配位结构。紫外光谱的数据表明,掺杂数量相同的其他离子会干扰Eu和Tb配合物对紫外光的吸收。对混合配合物的荧光进行了详细的研究,结果表明:La(Ⅲ)、Gd(Ⅲ)、Y(Ⅲ)对铕和铽的发光有显著的增强作用,但对其发射峰位的影响不大,三种离子中Gd^(3+)的增强作用最大,且掺杂量对荧光增强作用也有影响。

The study of the rare earth complexes continues to be an active research area, which may be attributed to the specific spectroscopic and magnetic properties of rare earth ions and the abundance of rare earth elements in our country. Amide type podands, which are flexible in structure and have terminal-group effects＇, will shield the encapsulated rare earth ion from interaction with the surroundings effectively, and thus achieve strong luminescent properties. The fluorescence intensities of Eu and Tb complexes, which exhibit the characteristic emissions of Eu^3＋ and Tb^3＋ respectively, can be increased by mixing with some non-fluorescent ions quantificationally and their costs can be also decreased. So, in our work the white complexes of Eu^3＋ , Tb^3＋, 1/2Eu^3＋ and 1/2RE^3＋, 1/2Tb^3＋ and 1/2RE^3＋ （RE^3＋ = Ga^3＋, Gd^3＋, Y^3＋ ） with 1,6-bis[（2＇- benzylaminoformyl） phenoxyl] hexane （L） have been synthesized in the solution of ethyl acetate and chloroform. The elemental analysis shows that Eu and Tb complexes conform to a 2：3 metal-to-ligand stoichiometries 2RE（ NO3 ） 3 · 3L · nH2O （RE = La, n = 2 ; RE = Eu, Gd, Tb, Y,n = 4）. Their IR spectra are recorded on a Bruke FTS66V/S spectrophotometer with KBr pellet in the range of 400 - 4 500 cm^- 1. The results indicate that all complexes have similar IR spectra, of which the characteristic bands have similar shifts, suggesting that they have a similar coordination structure. Their UV-VIS spectra are recorded on a Hitachi U-3010 spectrophotometer and show that mixed with identical molar ratio of La, the absorbance of Eu-La mixed complex is lower than that of Eu complex. Fluorescence spectra of the complexes were carried out on a Hitachi F4500 spectrophotometer at room temperature. The excitation and emission slit widths are 1.0 nm. The best excitation wavelengths for Eu and Tb complexes are 396 nm and 320 nm respectively. It can be concluded from the results that mixed with identical molar ratio of La^3＋ , Gd^3＋ and Y^3＋, Eu（ NO3 ）3 and Tb（ NO3 ）3 complexes exhibit the characteristic emissions of Eu^3＋ and Tb^3＋ respectively and their fluorescence intensities are sensitized and increased by La^3＋ , Gd^3＋ and Y^3＋, of which Gd3 ＋ has the strongest effect. But their peak positions did not change obviously. The mixed amount can also affect the fluorescence intensities of the mixed complexes. Take EuLa and TbGd complexes for example, when the molar ratio of Eu and La in the mixed complexes is equal to 0.9： 0.1, the fluorescence of the complex is the strongest, and the same to TbGd complexes. In a conclusion, La^3＋ , Gd^3＋ complexes and do not change the can affect the sensitization. and Y^3＋ can sensitize and increase the fluorescence intensities of Eu and Tb peak positions. Moreover the mixed amount of these non-fluorescence ions