【作者】 毛杰；

【导师】 刘伟生；

【作者基本信息】 兰州大学 ， 无机化学， 2009， 博士

【摘要】 本论文设计制备了一系列荧光体系，并对设计制备的荧光体系进行了性质研究。目前研究较多的荧光体系主要有纳米量子点荧光体系、有机分子荧光体系、无机金属配合物荧光体系等。每种荧光体系都有各自特有的性能，根据这些特性就可以设计出不同功能的荧光体系和器件。主要内容分为六章。第一章，阐述了量子点体系荧光体系、有机分子体系荧光体系、金属离子体系荧光体系的定义、结构、特征、发光性质等，重点介绍了各种荧光体系的合成以及各种荧光体系所具有的独特性能，和应用这些特性作为光学材料设计的研究现状。第二章，设计制备了高量子产率的硫化镉量子点。在我们的研究工作中，通过改变以往传统的策略，利用不同分子量的聚乙烯亚胺来修饰硫化镉量子点，成功的提升了量子产率，量子产率达到95％左右接近百分之百。成功设计出了一种简单的水相中的高量子产率的量子点合成方法。第三章，用光谱法（包括荧光光谱、吸收光谱等）研究了硫化镉量子点、有机分子吖啶橙和DNA体系的反应机理。发现吖啶橙与量子点之间存在能量转移作用，同时硫化镉淬灭作为受体的吖啶橙分子的荧光。通过实验，研究了体系中能量转移和荧光淬灭等问题。DNA的加入可以显著增强量子点硫化镉与吖啶橙体系中吖啶橙分子的荧光强度，据此建立了测定DNA的方法，该方法检测限达低(4．39ng mL^-1)，线性范围宽(60-4000 ng mL^-1)。第四章，利用“关-开”荧光分子开关原理，设计合成了二个结构相近的具有罗丹明骨架的荧光分子Rh1和Rh2。吸收和荧光光谱的测试结果表明，荧光分子Rh1在HEPES中性缓冲溶液中能高选择性的识别Fe³⁺，并产生荧光增强。Rh1在常见金属离子中Cd²⁺、Co²⁺、Cu²⁺、Ni²⁺、Zn²⁺、Mg²⁺、Ba²⁺、pb²⁺、Na⁺和K⁺中能够识别Fe³⁺，并且荧光增强现象非常明显，荧光强度增大了约22倍。然而，荧光分子Rh2在HEPES中性缓冲溶液中能高选择性的识别Cr³⁺，并且产生荧光增强。Rh2在常见金属离子中Cd²⁺、Co²⁺、Cu²⁺、Ni²⁺、Zn²⁺、Mg²⁺、Ba²⁺、pb²⁺、Na⁺和K⁺中能够识别Cr³⁺，并且荧光增强十分明显，荧光强度增大了约61倍。Rh1和Rh2都具有很高的灵敏度，成功地设计了分别对Fe³⁺和Cr³⁺的荧光传感器。第五章，设计合成了Schiff碱类Zn²⁺离子荧光传感器，并且研究了配体CB1在乙醇／水（9：1 V／V）的混合溶液中与金属离子相互作用后的光谱性质，并且通过（1）与结构类似的配体CB2和配体CB3比较（2）计算化学的计算，得出了配体CB1的作用方式并且讨论了作用机理。配体CB1与Zn²⁺配位后，荧光强度增大了65倍，其最大吸收波长为390nm，最大发射波长为493nm。第六章，对配体L和铕（Ⅲ）、铽（Ⅲ）形成的配合物的光学性质进行研究和讨论。铕（Ⅲ）配合物形成了双核笼状结构，一种相对封闭的结构体系。而铽（Ⅲ）配合物则形成螺旋聚合链，一种比较开放的结构体系。通过对比两种配合物荧光寿命和量子产率，表明配体与Tb³⁺之间的能级匹配程度比与Eu³⁺的能级匹配程度更好一些。并且发现铕（Ⅲ）和铽（Ⅲ）配合物对pH值的影响显示了不同的结果：铽（Ⅲ）配合物的荧光强度是随着pH变化而变化的，表现出很明显的荧光开关性能；铕（Ⅲ）配合物则没有这种性能，因为在相同条件下铕（Ⅲ）配合物的荧光强度太弱不能被检测出。更多还原

【Abstract】 This dissertation is based on a large number of literature and lots of experimentdata, and mainly focuses on the design, synthesis, and character research of a series offluorescent systems, including quantum dots fluorescence, organic moleculefluorescence and inorganic metal complex fluorescence system. Every fluorescencesystem has its own unique characters. Based on these characters, they can be designedfor different functional fluorescence materials and devices. This dissertation is dividedinto six chapters.In chapter 1, this chapter introduces the review about the definition offluorescent materials, structure, characteristics and luminescence properties offluorescent materials including quantum dot system, organic molecule system, metalion system and the presentation of the synthesis of a variety of fluorescent materialswith unique character and research progress in this field.In chapter 2, this chapter presents a simple method to synthesis CdS quantumdots with a high quantum yield. In our work, by changing the traditional strategy, weapply polyethyleneimine with different molecular weight to modified CdS quantumdots, in order to enhance the quantum yield, which reaches about 95% close to 100%,and, successfully, developed a simple method to synthesis high quantum yieldquantum dots in aqueous solution.In chapter 3, we discovered that there was FRET between CdS QDs (λ_em=480nm) and acridine orange (λ_ex=490 nm), meanwhile, to our surprise, CdS quenched thefluorescence of AO. And DNA enhanced fluorescent signals of the system of AO andCdS. The enhanced extents were in good proportion to DNA concentrations. Based onthis, a novel sensitive method was employed to determine DNA with good selectivityand sensitivity. The calibration curve was linear over 60-4000 ng mL^-1. Thedetermination limit （3σ） was 4.39 ng mL^-1. The method was applied to thedetermination of DNA in synthetic samples with satisfied results. The fluorescence ofAO is quenched by forming AO-CdS ground state complex. In chapter 4, we synthesized two fluorescent chemosensors using rhodamine as afluorephore and were able to alter their selectivity to Fe（Ⅲ） and Cr（Ⅲ） by tinystructure alteration of the recognition moiety. The selectivity of Rh1 and Rh2 wasswitched between Fe（Ⅲ） and Cr（Ⅲ） at neutral pH value （7.2） in 100% aqueoussolution, depending on their structures. Commonly coexistent metal ions, e.g. Cd²⁺,Co²⁺, Cu²⁺, Ni²⁺, Zn²⁺, Mg²⁺, Ba²⁺, Pb²⁺, Na⁺, and K⁺ displayed little interference toboth Rh1 and Rh2.In chapter 5, this chapter presents the design and synthesis of the schiff basefluorescent Zn²⁺ sensor CB1. And, in ethanol / water （9:1Ⅴ/Ⅴ） mixed solution, theabsorbance and fluorescence characters of the interaction of ligend CB1’s and metalion were studied. Combined compared with similar structure ligand CB2 and CB3 andcomputational chemistry calculations, we obtained the interaction mechanism of CB1and Zn²⁺. The fluorescence intensity of CB1 is able to increase 65 times due to Zn²⁺addition with maximum absorption wavelength at 390 nm, maximum emissionwavelength at 493 nm.In chapter 6, this chapter presents the study and discussion of lanthanidecomplex’s optical properties. The EuL complex forms a dual-core cage-like structurewith a relatively closed system. And the TbL complex forms a helical polymer chain, amore open structure. Due to the data of fluorescence lifetime and quantum yield, theenergy level between the ligand and Tb（Ⅲ） matches better than that between theligand and Eu（Ⅲ）. Furtermore, Eu（Ⅲ） and Tb（Ⅲ） complex shows different responseto pH value.The fluorescence intensity of Tb（Ⅲ） complex changes with pH changing,displaying fluorescence switch phenomenom; Eu（Ⅲ） complex do not have such aproperty, under the same conditions, the fluorescence intensity of Eu（Ⅲ） complex istoo weak to detect.更多还原