【作者】 张骞；

【导师】 吴杰颖； 田玉鹏；

【作者基本信息】 安徽大学 ， 无机化学， 2010， 硕士

【摘要】 双光子诱导荧光材料由于其良好的穿透性,高的空间选择性和分辨率,在生物显影、三维光存储、三维微加工等方面具有巨大的应用潜力,引起了人们极大的兴趣,是非线性领域应用范围最广的材料之一。嘧啶环具有较高的离子化电位及高的反应活性,很容易利用简单的反应对其进行修饰。更重要的是,嘧啶环作为DNA四大碱基之一,具有很好的生物相容性和活性,在生物模拟、电致发光等方面具有广泛的研究背景。本文设计、合成了七种新型嘧啶衍生物,通过多种手段表征了它们的结构,从实验上研究了所得材料的单、双光子光学性质,并通过理论计算进行了验证,所得的一系列有价值的成果,将为此类双光子荧光材料的应用探索提供参考。主要研究内容如下：1.通过对双光子荧光材料的研究历史、研究现状进行综述,对嘧啶类衍生物双光子荧光材料的研究可行性、前景、意义做了论述。在文献调研的基础上选择嘧啶类衍生物为底物,设计七种目标化合物,以期得到具有大的双光子吸收截面的分子。2.通过多步有机反应,高产率合成了所设计的目标化合物,并用红外、质谱、核磁、元素分析等手段对中间体和目标化合物进行了表征,通过单晶x-射线衍射解析了其中两种化合物的结构。发现该系列化合物中的苯乙烯共轭桥均为反式结构,且发现化合物的结构特点和堆积模式与2位取代基有很大的关系：随着2位取代基吸电子能力的增加,分子扭曲程度增加,平面性变差；其中,化合物Z7属于P21／c空间群,化合物Z10属于P212121非中心对称空间群,分子堆积呈现网状结构,这类分子可作为倍频晶体材料。3.系统研究了所合成的嘧啶类衍生物的线性和非线性光学性质,研究结果表明,目标化合物在不同溶剂中都有很大的荧光量子产率,且单光子荧光量子产率随嘧啶2位取代基吸电子能力的增强而提高；目标化合物还具有很强的非线性光学性质,且随着2位取代基吸电子能力的增强,非线性光学效应增强。理论计算结果表明,主要出峰都归属于电子从HOMO轨道到LUMO轨道的跃迁,是供体(D)与受体(A)之间的作用,从理论上验证了D-π-A-π-D的构型能够加强电子流动,增大双光子吸收截面,提高双光子吸收活性的结论。更多还原

【Abstract】 Two-photon induced fluorescence(TPEF) materials have great potential applications in bio-imaging, three-dimensional optical storage and three-dimensional micro-processing applications, due to its good penetration, high spatial selectivity and resolution, which are the most widely used materials in non-linear field of application. Pyrimidine, one of the four bases of DNA, has good biocompatibility and activity, with a broad research background in biological simulation, electroluminescence and so on. Additionally, it has a high ionization potential and high reactivity, to be easily modified. The current survey on TPEF materials in international material field are reviewed in the dissertation. Seven novel organic chromophores based on pyrimidine have been designed, synthesized and characterized. Single-and two-photon optical properties of the synthesized compounds were investigated both experimentally, and theoretical. Furthermore, The valuable results and conclusions were provided for investigation on TPA materials. The research was introduced as follows:1. Through overlook the research on two-photon fluorescent materials, a brief history and the current development of TPEF materials were reviewed, the feasibility and significance of pyrimidine derivatives with two-photon activifies were elucidated. Based on reviewing, we designed seven target compounds, with a large two-photon absorption cross sections.2. Seven pyrimidine derivatives were synthesized and characterized by IR spectra, Mass spectrum,1H-NMR spectra, 13C-NMR spectra and Elemental analysises (C, H, N). the single-crystal structure of two compounds were analyzed. Of these, compound Z7 crystalizes in P21/c space group, compound Z10 in non-centrosymmetric space group P212121, showing network structure.The crystal should exhibit second harmomic generation response.3. The linear and nonlinear optical properties of pyrimidine derivatives were investigated. The target compounds in different solvents has a high fluorescence quantum yield, which decrease with the electron withdrawing ability of substituent attached to the pyrimidine 2 unit. The results showed that nonlinear response of the compounds increase with the electron withdrawing ability of substituent attached to pyrimidine at 2 unit. Theoretical caclulation show that the main peaks are from the HOMO to LUMO orbital of the transition, that is, the donor (D) and acceptor (A), which also verified the D-π-A-π-D configuration can enhance and improve the two-photon response.更多还原