光致发光稀土（铕、铽）配合物的合成、荧光性能及理论研究

【作者】 周忠诚；

【导师】 舒万艮；

【作者基本信息】 中南大学 ， 应用化学， 2002， 博士

【摘要】 稀土有机配合物发光是无机发光与有机发光、生物发光研究的交叉学科，有着重要的理论研究意义和应用研究价值。稀土有机荧光配合物因镧系离子独特的电子结构而成为一类具有独特性能的发光材料。在激光、光致发光、电致发光配合物等领域有潜在的应用价值。本文从比较廉价的苯甲酸衍生物配体与稀土铕、铽的二元配合物入手，研究第二配体的协同效应和掺杂离子的荧光增强效应，逐步提高配合物的荧光性能。主要工作主要分为四部分： 1．合成了铕、铽与苯甲酸及其衍生物(苯甲酸、邻苯二甲酸、间苯二甲酸、邻氨基苯甲酸、磺基水杨酸)的二元配合物。比较了各配合物的荧光强度。荧光光谱的研究表明，铽与这六个配体的二元配合物都表现出较好的荧光性能，并发现磺基水杨酸铽配合物在本实验系列中荧光发射最强，比文献报道认为最好的邻氨基苯甲酸铽还要强，甚至比目前所报道的铽的无机发光材料的发光性能还要好。而铕与这些配体的二元配合物的荧光性能比相应的铽的二元配合物要差，其中铕与苯甲酸、邻苯二甲酸及间苯二甲酸表现出较好的荧光性能，而铕与磺基水杨酸、邻氨基苯甲酸、水杨酸的配合物却主要表现出配体的宽带发射。 首次采用微波固相合成的方法合成了磺基水杨酸铽，通过其红外光谱和X-衍射分析发现固相合成产物与溶液合成的产物具有相同的配位结构和晶体结构。 关于磺基水杨酸与铕、铽的固态二元配合物的合成及荧光性能未见文献报道。 2．合成了铕、铽的异配体三元配合物。主要研究了配合物的紫外光谱，红外光谱和荧光光谱。在铕的二元配合物中，第二配体邻菲罗啉(Phen)、邻菲罗啉N氧化物(PhenN-O)、2，2-联吡啶(Bipy)、二安替吡啉甲烷(Ant)、三正辛基氧化膦(TOPO)的加入，显著提高了配合物的荧光强度。 在铽的二元配合物中，加入第二配体TOPO、Bipy、Ant都能在一定程度上敏化Tb(Ⅲ)的发光，增加配合物的荧光性能，而加入第二配体Phen形成三元配合物，其荧光强度反而比相应的二元配合物的荧光强度还低， 首次提出第二配体负协同效应的概念和三元配合物的分子内的能量传递机理。很好地解释了为什么Phen的引入降低了铽的三元配合物的荧光强度(第二配体的负协同效应)，而增加了铕的三元配合物的荧光强度(第二配体的正协同效应)。 3．首次合成了铕-甲基丙烯酸-邻菲罗啉、铕-噻吩甲酰三氟丙酮-邻菲罗啉、铽-邻氨基苯甲酸以及铽-磺基水杨酸四个体系的系列掺杂配合物。主要研究了系摘要列配合物的红外光谱、X一衍射分析以及荧光光谱。 (l)铺一甲基丙烯酸一邻菲罗琳掺杂体系。研究了Gd3+、L扩十、Y3+三种掺杂离子及其掺杂摩尔分数对配合物荧光性能的影响。从荧光强度来看，当Gd3+离子的的摩尔分数为0.9时，样品的发光强度达到最大值。当L扩+离子的摩尔分数为0.9时，掺杂配合物的发光强度最大，当Y3十离子的摩尔分数为0.4时，掺杂配合物的发光强度最大。 (2)铺一唆吩甲酞三氟丙酮一邻菲罗琳掺杂体系。研究了Gd3+、L扩+、Y3+三种掺杂离子及其掺杂摩尔分数对配合物荧光性能的影响。从荧光强度来看，当Gd3+离子的的摩尔分数为0.4时，样品的发光强度达到最大值。当La3+离子的摩尔分数为0.5时，掺杂配合物的发光强度最大，当Y3+离子的摩尔分数为0.2时，掺杂配合物的发光强度最大。 (3)试一邻氨基苯甲酸掺杂体系。研究了Gd3+、La3+、Y3+、z矿十四种掺杂离子及其掺杂摩尔分数对配合物荧光性能的影响。，从荧光强度来看，当Gd3+离子的的摩尔分数为0.9时，样品的发光强度达到最大值。当La3+离子的摩尔分数为0.7时，掺杂配合物的发光强度最大，当Y3+离子的摩尔分数为0.5时，掺杂配合物的发光强度最大，当z矿十离子的摩尔分数为0.5时，掺杂配合物的发光强度最大。 (4)试一磺基水杨酸掺杂体系。研究了Gd3+、La3+、Y3+、zn2+四种掺杂离子及其掺杂摩尔分数对配合物荧光性能的影响。从荧光强度来看，当Gd3+离子的的摩尔分数为0.4时，样品的发光强度达到最大值。当La3+离子的摩尔分数为0.6时，掺杂配合物的发光强度最大，当Y3+离子的摩尔分数为0.6时，掺杂配合物的发光强度最大，当Zn2+离子的摩尔分数为0.5时，掺杂配合物的发光强度最大。 为进一步研究掺杂离子的荧光增强效应，首次引入了R和Q两个参数。R二I献I，荧光增强因子Q，定义为Q二(R一1)/X。R为掺杂配合物的实测的荧光强度与计算的荧光强度之比，x为掺杂离子的摩尔分数。通过R值我们知道掺杂离子摩尔分数对荧光强度的影响;通过Q值，我们知道对于某一掺杂体系，各种掺杂离子整体上对荧光强度的影响。 提出了掺杂离子荧光增强效应的机理。 4.首次采用ab initio CIS方法，在劈裂价层基组3一21G水平上对各配体进行了量化计算，系统分析了前线分子轨道特征和激发态的能级，从配体最低激发三重态能级与稀土离子共振能级的能级匹配，分析了铺与p一二酮的配合物的荧光性能和锹与苯甲酸系列衍生物的配合物的荧光性能，解释了第二配体的协同效应。更多还原

【Abstract】 The study of rare earth complexes luminescence, being the cross science of inorganic materials luminescence, organic materials luminescence and organism luminescence, is very important for fundamental and applied research. Rare earth complexes have become excellent luminescence materials, this is related to lanthanide ions’ peculiar characteristics. And have potential use in laser, photoluminescence and electroluminescence. In this paper, we study the synergetic effects of second ligands and luminescence enhancement effects of doping ions starting from the binary complexes of europium and terbium with inexpensive benzoic acid and its derivatives, and improve the luminescence of complexes step by step. The main work is divided into four parts:1. The binary complexes of europium and terbium with benzoic acid and its derivatives (phthalic acid, m-phthalic acid, o-aminobenzoic acid, salicylic acid, sulfosalicylic acid) were Synthesized and their fluorescence properties compared .The IR spectra showed that the IR spectra of complexes are different from those of free ligands. The fluorescence properties of them were investigated by using luminescence spectroscopy, the results showed that all the six complexes of terbium exhibited excellent luminescence, and the complexes of terbium with sulfosalicylic acid had the strongest fluorescence intensity, and was stronger than o-aminobenzoic acid-terbium, whose fluorescence intensity was regarded as the strongest one in the literature, and even stronger than some phosphor of terbium. To europium ion, their fluorescence properties of its complexes with these ligands were inferior to corresponding terbium complexes, only three complexes show better luminescence, they were Eu-benzoic acid Eu-m-phthalic acid and Eu-phthalic acid, while the others exhibited the ligands’ wideband emission.Micro-wave solid synthesis method was applied in synthesizing Tb-sulfosalicylic acid for the first time. The results of IR and XRD manifest that the products of microwave solid synthesis method and precipicitation method have the same coordination and crystal structure.Synthesis and fluorescence properties of solid Tb-sulfosalicylic acid were not reported in the literature.2. The ternary complexes of europium and terbium were synthesized and characterized by UV, IR and Fluorescence Spectra. In the binary complexes of europium, the introduction of the second ligands, 1,10-phenanthroline, 1,10-phenanthroline-N-oxide, 2,2-bipyridine,diantipyryl methane, trioctylphosphine oxide, could improve the fluorescence intensity greatly.In the binary complexes of tebium, the introduction of the second ligands, 2,2-bipyridine,diantipyryl methane, trioctylphosphine oxide, could can improve the fluorescence intensity to some extent, while the introduction of 1,10-phenanthroline, just reduced the fluorescence intensity, ie, the fluorescence intensity of the ternary complexes was inferior to that of binary complexes.The concept of negative synergistic effect of the second ligand and the mechanism of intra-molecule energy transfer of ternary complexes was firstly put forward, which accounted for why the introduction of 1,10-phenanthroline reduced the fluorescence intensity of ternary complexes of terbium(the negative synergistic effect of the second ligand) and improved the fluorescence intensity of ternary complexes of europium(the positive synergistic effect of the second ligand).3. A series of doped complexes of Eu-methacrylic acid-Phen , europium-TTA-Phen, Tb- o-aminobenzoic acid and Tb- sulfosalicylic acid four systems were synthesized and characterized by IR, XRD and Fluorescence Spectra.(l)The doped system of Eu-methacrylic acid-Phen. The effects on fluorescence properties of complexes of three doping ions(Gd3+, La3+ and Y3+) and their mole fraction were investigated and compared. For fluorescence intensity ,when x Gd was 0.9, x La was 0.9, x Y was 0.4, the corresponding doped complexes was the strongest in their respective series complexes.(2更多还原