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1、摘要稀土聚合物由于兼具稀土离子发光强度高、色纯度高和高分子材料优良的加工性能等 长处而倍受瞩目。以化学键结合的形式将稀土配合物与聚合物连结在一起,生成的键合型 的稀土聚合物,可以使稀土配合物均匀地分布在聚合物基体中,在稀土含量较高时仍具有 优良的荧光性能,并且其荧光强度随稀土离子含量的增长而增强,呈现出线性递增的现象。 目前,多数研究运用丙烯酸与稀土的键合伙用将C=C双键引入到稀土配合物中,再与甲 基丙烯酸甲酯、苯乙烯等烯类单体共聚,制得键合型的稀土高分子复合材料。但应当指出, 这些键合型的复合材料中,丙烯酸类配体对稀土离子的荧光发射奉献不明显,但是却占用 了稀土离子的一部分派位数,明显影响了
2、材料的荧光性能。本文旨在通过多功能配体的设 计来合成具有高荧光强度的稀土聚合物,发展高性能稀土聚合物发光材料的合成与制备方 法。论文的重要内容如下:1)针对邻菲罗啉和8羟基喹啉配体具有刚性大、吸光系数大、配位能力强等特点, 设计合成了基于这两种物质的多功能配体5丙烯酰胺基1,10邻菲罗啉(Aphen)和5 丙烯酰氧乙氧基甲基8羟基喹啉(Hamq),并对合成工艺进行了优化。分别实验考察了两 种配体的荧光发射光谱及低温磷光光谱,发现两者都具有具有较强的向稀土离子能量转移 的趋势,它们的最低三重态能级分别为0和22370 cm-1,与Eu3+离子的共振发射 能级(5Do,17200 cm-1)具有良
3、好匹配,其中,配体Aphen的匹配限度优于Hamq。2)研究了系列配合物E邶-diketone)3(Aphen)、Eu(TTA)z(amq)、Eu(TTA)3(H20)2、Eu(TTA)2(AA)的光物理性能(光色纯度、荧光强度、荧光寿命、量子效率等),发目前 Eu(fl-diketone)3(Aphen)系列配合物中,Eu(TTA)s(Aphen)的荧光性能最强(荧光寿命、量 子产率分别为590斗s、401),其5Do_7F2跃迁的荧光发射强度分别为配合物 Eu(TTA)3(H20)2、Eu(TTA)2(AA)和Eu(TTA)2(amq)的45、1 13和39倍。指出丙烯酸 配体AA对Eu3
4、+离子的发光基本不起作用,而配位水分子则对Eu3+离子的发光起到荧光猝灭作用,揭示了配体Aphen、Hamq敏化Eu3+离子发光的Antenna效应、协同效应。3)通过强荧光稀土配合物单体Eu(TTA)3(Aphen)、Eu(TTA)2(amq)分别与MMA的 共聚合反映成功地合成了基于邻菲罗啉和8羟基喹啉衍生物的键合型强荧光稀土聚合物III复合发光材料。实验考察了稀土聚合物的红外光谱、紫外光谱、核磁共振氢谱、分子量及 其分布、热稳定性、荧光寿命、荧光激发及发射光谱,发现:稀土配合物单体具有良 好的共聚合性能,其构造单元在聚合及提纯过程中不容易解离;稀土配合物构造单元 的引入有助于提高共聚物的
5、热稳定性及玻璃化转变温度;共聚物中甲基丙烯酸甲酯单 元虽参与配位,但是起能量传递作用的重要物质仍然是TTA;共聚物的荧光同样体现 为稀土离子的特性发射,均观测到5Do一7FJ(J=0-4)的跃迁,其中5Do一7F2跃迁的强 度最大,在所研究的Eu含量范畴内,共聚物荧光强度随Eu含量增长而增大,没有浮现 明显的荧光猝灭现象。指出共聚物荧光性能的提高与配合物构造单元在聚合物基质中所处 的微环境有关:一方面由于甲基丙烯酸甲酯单元参与配位,使得稀土配位趋于饱和,从而 荧光性能大为增强;另一方面由于配合物单体与MMA共聚后,每一种配合物单元都被 PMMA柔韧链环绕,并且还也许被高分子链扭曲,稀土离子就象
6、被圈在聚合物的笼子中 同样,产生所谓的“笼蔽效应”,在这种特殊的构象下,稀土小分子配合物单元之间的互相 作用变得非常单薄,稀土离子的汇集体不容易生成,同步由于高分子链的介入,更进一步 减少了Eu3+的对称性,增长了5Do_7F2跃迁的也许性。4)在Eu(TTA)2(amq)PMMA的共混体系中,当Eu的含量较低时,共混物的荧光 强度随Eu含量的增长而增强,基本呈现了良好的线性关系,当Eu=330 wt时,荧 光强度值达到最大,在此后来,随Eu的增长荧光强度逐渐减少,浮现荧光猝灭现象。核心词:稀土聚合物,键合型,强荧光,合成,研究IvAbstractThe rare earth polymer
7、materials have attracted considerable interests for their good luminescent characteristics,high color purity of rare earths and the excellent processability of polymersThe bondingtype rare earth polymers in which the lanthanide complexes are covalently bound in the main chain would cause the lanthan
8、ide complexes to distribute evenly in the polymer marixes,and could still maintain the luminescence intensity when the rare earth metal content is hi曲Furthermore,the luminescence intensities of the polymers increase linearly with an increase in the rare earth contentUp to nOW most of the approaches
9、to bind a lanthanide complex to a polymer backbone take advantage of a polymerizable ligand such as acrylic acidBut it should be noted that the acrylic acid ligand makes little contribution to theluminescence of the complexes,and occupies the coordination number of rare earth ions,which would signif
10、icantly affect the luminescence properties of the polymersThis thesis aims to synthesize highly luminescent rare earth polymers through the design of multifunctional ligands, and to develop the synthesis and preparation methods for the rare earth polymer luminescent materials with high performanceTh
11、e following results have been achieved:1)Two multifunctional ligands,5-acrylamido-1,1 0-phenanthroline(Aphen)and 5-acryloxyethoxymethyl-8-hydroxyquinoline(Hamq),were designed and synthesized,and their synthesis processes were optimizedOur design is based upon the fact that the ligands phenanthroline
12、 and 8-hydroxyquinoline have characteristics of big rigid planar,large absorptioncoefficient,and strong coordinationThe luminescence emission spectra and the lowtemperature phosphorescence spectra of the two ligands were studied,and the experimental results showed that they have a strong tendency of
13、 energy transfer to the rare earth ion,and that the triplet state energies of Aphen and Hamq were 0 and 22370 cml,respectively,which are much higher in energy than the resonance levels of Eu3+(5Do,1 7200 cm-1),indicating thatthe triplet state energies of the two ligand are suitable for the sensitiza
14、tion of the luminescenceof Eu3+,especially Aphen2)The photophysical properties(color purity,luminescence intensity,lifetime,andVquantum yield)of a series Euffldiketoneh(Aphen)complexes,complex Eu(TTA)2(amq), Eu(TTA)3(H20)2 and Eu(TTA)2(心were investigatedThe results showed that the complexEu(TTA)3(Ap
15、hen)has the strongest luminescence emission among the seriesEu(fl-diketone)3(Aphen)complexes,and its luminescence intensity of 5Do一7F2 transition is 45,1 13,and 39 times aS hi曲as that of Eu(TTA)3(H20)2、Eu(TTA)2(AA)and Eu(TTA)2(amq), respectively,indicating that the acrylic acid ligand plays little or no role in the luminescence of Eu(TTA)2(AA)and the coordinated water molecules carl effectively quench the luminescence intensity of Eu(TTA)3(H20)2,and that the ligands Aphen and Hamq Call sensitize the