为研究稀土荧光络合物与高分子形成的复合物的结构与发光性能间的关系,利用α-噻吩甲酰三氟丙酮(TTA)和三苯基氧化膦(TPPO)与氯化铕(EuCl3)分别制备了Eu(TTA)3·2H2O和Eu(TTA)3·(TP-PO)2络合物,及其与聚乙烯吡咯烷酮(PVP)的复合物。采用荧光光谱,红外光谱和透射电镜等方法对复合物进行了表征。荧光光谱测定结果表明Eu(TTA)3·2H2O与PVPK30结构单元摩尔比为1∶35的PVP/Eu(TTA)3·2H2O复合物的612nm发射峰的荧光强度较Eu(TTA)3·2H2O络合物有显著提高。红外光谱研究表明络合物的Eu^3+与PVP分子的羰基之间存在着明显的配位作用,并且存在多种配位方式。透射电镜观察结果表明复合物具有微相分离结构,其中的稀土络合物为无定形结构,这进一步表明PVP与络合物分子间存在相互作用。
In order to investigate the relationship between the aggregation structure and fluorescence properties of composites of rare earth fluorescent complexes and polymers, the fluorescent complexes of Eu(TTA)3·2H2O and Eu(TTA)3·(TPPO)2 were synthesized by the reaction of TTA(2-thenoyltrifluoroacetone), TPPO(triphenylphosphine oxide) and EuCl3, and their composites with polyvinylpyrrolidone (PVP K30) were prepared. The fluorescence spectroscopy, FTIR spectroscopy and TEM were used to characterize these composites. Fluorescence spectroscopy results indicated that the fluorescence intensity of the PVP/Eu(TTA)3·2H2O composites is obviously improved compared with that of the Eu(TTA)3·2H2O complexes. For the composites with the molar ratio of the complexes to the repeat unit of PVP being 1∶35, the intensity of 612nm emission peak of the composites is 5.5 times for PVP/Eu(TTA)3·2H2O and 0.3 times for PVP/Eu(TTA)3·(TPPO)2 higher than that of the corresponding pure rare earth fluorescent complexes. And the emission intensity ratio of 612 to 590 nm peak is 14.7 in PVP/Eu(TTA)3·2H2O composite, larger than that of Eu(TTA)3·2H2O complexes. These results suggested that the luminescent properties of the europium fluorescent complexes were obviously enhanced in the presence of PVP matrix and there are interactions between the fluorescence complexes and PVP molecules. In the presence of PVPK30, the FTIR spectra of the Eu(TTA)3·2H2O complexes were obviously influenced as well. Based on the curve-fitting results of IR spectra of PVP/Eu(TTA)3·2H2O composites with the molar ratio of repeat unit of PVP to Eu(TTA)3·2H2O being 7∶1 and 2∶1, multiple absorption peaks of νCO are observed. The IR spectral variations indicated that there are coordination interactions between Eu^3+ ions and the carbonyl groups of PVP, and multiple coordination fashion exists. TEM results showed that there are microphase separation structures in PVP/Eu(TTA)3·2H2O and PVP/Eu(T