【作者】 刘国德；

【导师】 酒红芳；

【作者基本信息】 中北大学 ， 高分子化学与物理， 2011， 硕士

【摘要】 以β-二酮为配体的稀土配合物，通过有机配体的强紫外吸收和配体向稀土离子的有效能量传递，使其发出稀土离子的强特征荧光，具有较好的紫外激发荧光性能。因此，设计并合成新型的β-二酮类化合物，对于寻找和开发新型稀土离子发光敏化剂具有重要意义，同时设计配体的分子结构也是寻找新型稀土离子发光敏化剂的关键。本文以3,4,5-三羟基苯甲酸甲酯为原料，经Claisen缩合反应，设计并合成了2种新型的未见文献报道的β-二酮配体：1,5-二（3,4,5-三羟基）苯甲酰基乙酰丙酮（L₁）和1-（3,4,5-三苄氧基）苯基-5-苯基乙酰丙酮（L₂）。合成的配体及中间体的结构通过傅里叶变换红外光谱（FT-IR）、元素分析（EA）、热重分析，氢核磁共振谱（1^H-NMR）等表征手段得以确定。通过稀土（Eu，Tb）硝酸盐与配体L₁合成了一种双核配合物Tb2（L₁）₃·4H₂O；与配体L₂分别合成了两种三元配合物Ln（L₂）3phen和两种二元配合物Ln（L₂）₃·2H₂O。通过FT-IR与EA确定配合物的结构，TG-DSC分析了配合物的热稳定性；以二甲酚橙作为指示剂，采用EDTA滴定法测定了稀土含量。结果表明，五种配合物结构与预期结构相符，且具有较高的热稳定性。同时，还测定了配合物的荧光性能。结果表明：配合物中的有机配体L₁和L₂能够有效地的把吸收的能量传递给稀土中心离子，强烈敏化中心离子发光，具有大的共轭体系的配体的荧光敏化性能要优于共扼体系小的配体；对于不同配体而言，L₂配体合成的三元配合物和二元配合物的荧光强度均高于由配体L₁合成的配合物；对同一类型的配体而言，Tb（Ⅲ）配合物一般比Eu（Ⅲ）配合物具有更高的荧光强度，与二元配合物相比，三元配合物中第二配体phen的引入明显地增强了配合物的荧光强度。通过测试计算表明：配体L₂合成的Tb（Ⅲ）配合物比Eu（Ⅲ）配合物具有更高的量子效率。这些配合物荧光半峰宽窄，单色性好，对发展新型稀土配合物发光材料有一定的价值。更多还原

【Abstract】 The lanthanide complexes withβ-diketone ligands have high ability of UV-vis excitationfluorescence, and the ligands make rare earth ions emit strong characteristic fluorescence byorganic ligands’strong UV-vis absorbance and efficient energy-transfer between the ligandsand lanthanide ions. Therefore，designing and synthesizing novelβ-diketone kind ofcompounds is of great importance for searching and developing novel sensitizers for rareearth ions and designing the structures of ligands is also a key point to discover newfluorescent sensitizers of rare-earth ions.Two novelβ-diketone ligands named 1,5-bi（3,4,5-trihydroxy） benzoylacetylacetone（L₁）and 1-（3,4,5-trisbenzyloxy）benzoyl-5-benzoyl acetylacetone （L₂） were synthesized startingfrom 3,4,5-trihydroxybenzoate as the raw material through Claisen reaction. The structures ofboth ligands were charaeterized by the Fourier transform infrared （FT-IR） spectrum,elemental analysis（EA），thermal analysis and proton nuclear magnetic resonance （1H-NMR）in detail.One dinuclear complex Tb2（L₁）₃·4H₂O , two ternary complexes Ln（L₂）3phen and twobinary complexes Ln（L₂）₃·2H₂O were synthesized by the reaction of rare earth chloride （Eu，Tb） with ligand L₁ and L₂, respectively. The structures of all complexes were charaeterized byFT-IR, EA. The thermal analysis of complexes was examined by TG-DSC. The content ofEu（III） and Tb（III） were determined by EDTA titration with xylenol orange as an indicator.All results show that the structure of the five complexes is entirely consistent with expectedcomplexes and the complexes have higher thermostabilityMeanwhile, the fluorescence properties of complexes were measured. The results showthat the effective energy transfer process occurred form the ligands L₁ and L₂ to lanthanideions, and subsequently the central ions can be sensitized effectively. The ligand which haslarger conjugate system is a better fluorescence sensitizer than the smaller conjugate system ligands. In particular，the ternary complex and binary complex of ligand L₂ have a muchhigher fluorescence intensity than the complex of ligand L₁. The Tb（Ⅲ） complex exhibit amore excellent luminescence property than the Eu（Ⅲ） complex for the same ligand. Morever,comparing to the binary complexes，the introduction of secondary ligand phen significantlyenhanced the luminescent intensity of ternary complex. Through testing and calculation, theresults show that Tb （Ⅲ） complex has higher quantum efficiency than Eu （Ⅲ） complex.The fluorescence emission of complexes is extremely narrow half-band width and goodmonochromaticity, which is significant for the developing of rare earth complexes efficientluminescent materials.更多还原