二氧六环参与配位的稀土配合物的制备和荧光性能研究

利用二氧六环(dioxane)小分子作为第二配体,吡哌酸(PPA)作为第一配体合成了稀土荧光配合物Eu(PPA)3dioxane和Tb(PPA)sdioxane.这种小分子直接参与配位形成稀土配合物的现象很少见到.所合成的配合物通过与单独使用吡哌酸作为配体的配合物Eu(PPA)3和Tb(PPA)3对比,发现二氧六环对稀土配合物的荧光具有明显的增强效果,尤其是对Tb3+所形成的稀土配合物,荧光增强非常显著.二氧六环的参与配位,代替了原来的水分子,这样就会在一定程度上减少了热振动所造成的能壁损失,从而增强荧光.所制备的稀土配合物通过红外光谱、荧光光谱、荧光寿命等方法进行了表征.对于由Eu和Tb所形成的配合物,加入第二配体二氧六环对其荧光寿命的影响差别很大,这说明对于Eu和Tb所形成的配合物存在着不同的能鸶传递过程.这种荧光增强现象为检测小分子二氧六环的存在及其含量提供了一种新的方法.

Synthesis and characterization of new lanthanide complexes using pipemidic acid (PPA) and dioxane as ligands

Eu(PPA)3 dioxane and Tb(PPA)3 dioxane were synthesized by firstly adopting dioxane as second ligand and using pipemidic acid (PPA) as first ligand. In contrast with two kinds of binary lanthanide complexes Eu(PPA)3 and Tb(PPA)3, the photoluminescent intensities of Eu (PPA)3 dioxane and Tb (PPA)3 dioxane are much stronger, especially for that of Tb(PPA)3 dioxane. The enhancement of photoluminescent intensities of Eu(PPA)3 dioxane and Tb(PPA)3 dioxane is because of the replacement of dioxane for water bonded to Eu3+ and Tb3+, by which the energy loss through heat oscillation will be inhibited. The as-synthesized lanthanide complexes were characterized by FT-IR, photoluminescence spectra and photoluminescence lifetime. The lifetime of Eu(PPA)3 dioxane and Tb(PPA) dioxane remarkably changed compared with those of Eu(PPA)3 and Tb(PPA)3. However, there is much difference for the lifetime change of as-synthesized lanthanide complexes formed by Eu3+ and Tb3+, which shows that there is different energy transfer process for the lanthanide complexes formed by Eu3+ and Tb3+. The synthesis of lanthanide complexes using dioxane as second ligand will provide a new method to detect the existence of dioxane.