基于四苯基乙烯的手性侧链聚炔的合成及性能研究

发布时间：2018-05-10 12:24

本文选题：聚炔 + 手性　；参考：《深圳大学》2017年硕士论文

【摘要】：本论文通过合理的分子设计将荧光基团和手性中心通过侧链修饰的方式引入到聚炔分子中,成功合成了两类具有聚集诱导发光(Aggregation-Induced Emission,简称AIE)特性的炔类聚合物,在对其分子结构表征的基础上探讨了手性及发光行为,主要内容分章节介绍如下:第一章主要介绍了聚炔化合物的结构、合成及催化剂类型,当在聚炔化合物结构中引入手性基团,会赋予圆二色性、圆偏振发光等分子特殊光学活性和物理性质。另外还简述了传统荧光材料的结构特征:具有大共轭、平面结构等特点,导致传统的荧光材料在集聚态或固态下荧光猝灭,从而限制了其实际的应用;为了解决这个问题,引出新型的AIE荧光材料。第二章简述了本论文实验过程中所使用的试剂、仪器和表征方法。第三章合成四个四苯基乙烯的手性侧链烷基炔单体,并通过自制的金属配位催化剂Rh+(nbd)[B(C6H6)4]-得到分子量大(Mw)、分子量分布适中的四个侧链修饰的聚乙炔高分子。首先,对聚合物进行了光谱表征,实验表明:在溶液含水量小于20%时,荧光很弱;之后,其荧光强度随含水量的增加而剧增。另一方面,在CD(Circular Dichroism)光谱上可以明显看到Cotton效应,说明手性中心的不对称性已经传递到主链上去。接着,通过向聚合物溶液中加入劣溶剂的方法观测了其CD信号的变化趋势,发现这些聚合物的CD响应都随劣溶剂含量的增加而减弱,在薄膜状态下CD信号甚至完全消失。另外,通过混合溶剂制样方法,能够在电镜下找到由聚合物分子自组装形成的螺旋结构。作者还对单体的光谱行为和手性性质进行了表征,结果表明:单体具有明显的AIE特征和手性。第四章对四个四苯基乙烯的手性侧链苯乙炔聚合物进行研究,使用自制的金属配位催化剂[Rh(cod)2Cl]2完成聚合。但因结构特点的约束最终只得到一个分子量大(Mw),分子量分布适中的侧链修饰聚苯乙炔分子。首先,对聚合物的研究发现:其荧光强度随劣溶剂含量的增加而增强,在CD光谱上表现出曲线的正负交替,具有AICD(Aggregation-induced Circular Dichroism)的性质,但薄膜的CD响应则完全消失。其次,其形貌研究发现,聚合物能自组装成有孔的微米球。最后,作者对单体的荧光及手性特征进行了表征,研究表明:单体具有显著的AIE活性和手性。第五章对论文实验和结果进行了系统总结和探讨。
[Abstract]:In this paper, fluorescence groups and chiral centers were introduced into polyacetylene molecules by side chain modification through reasonable molecular design, and two kinds of acetylene polymers with agglomeration-induced Aggregation-Induced Emissionation (AIEs) were successfully synthesized. On the basis of characterization of molecular structure, chiral and luminescent behaviors are discussed. The main contents are as follows: in Chapter 1, the structure, synthesis and catalyst types of polyacetylene compounds are introduced. When chiral groups are introduced into the structure of polyacetylene compounds, circular dichroism, circularly polarized luminescence and other special optical and physical properties will be given. In addition, the structural characteristics of traditional fluorescent materials are briefly described, such as large conjugation, planar structure and so on, which lead to fluorescence quenching of traditional fluorescent materials in concentrated or solid state, which limits their practical application. A new type of AIE fluorescent material was obtained. In the second chapter, the reagents, instruments and characterization methods used in the experiment are briefly described. In chapter 3, four chiral side chain alkyne monomers of tetraphenylethylene were synthesized, and four modified polyacetylene polymers with high molecular weight and moderate molecular weight distribution were obtained by using the self-made metal coordination catalyst Rh nbd) [B(C6H6)4]. The results show that the fluorescence is weak when the water content of the solution is less than 20, and then the fluorescence intensity increases sharply with the increase of the water content. On the other hand, the Cotton effect can be seen in the CD(Circular Dichrois spectra, indicating that the asymmetry of the chiral center has been transferred to the main chain. Then, by adding inferior solvent into polymer solution, the change trend of CD signal was observed. It was found that the CD response of these polymers decreased with the increase of the content of inferior solvent, and the CD signal disappeared completely in the film state. In addition, the helical structure formed by self-assembly of polymer molecules can be found under electron microscope by mixed solvent preparation method. The spectral behavior and chiral properties of the monomers were also characterized. The results showed that the monomers had obvious AIE characteristics and chiral properties. In chapter 4, the chiral side chain phenylacetylene polymers of four tetraphenyl ethylene were studied. The polymerization was completed by using the metal coordination catalyst [Rh(cod)2Cl] 2 made by ourselves. However, due to the restriction of structural characteristics, only a large molecular weight MwN with a moderate molecular weight distribution can be obtained by side chain modification of polyphenylene acetylene. Firstly, it is found that the fluorescence intensity of the polymer increases with the increase of the content of the inferior solvent, and the CD spectra show the positive or negative alternation of the curves, which have the properties of AICD(Aggregation-induced Circular Dichrois m), but the CD response of the films disappears completely. Secondly, it is found that the polymer can self-assemble into microspheres with pores. Finally, the fluorescence and chiral properties of the monomers were characterized. The results showed that the monomers had significant AIE activity and chirality. In the fifth chapter, the experiment and results are summarized and discussed systematically.
【学位授予单位】：深圳大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O632.17

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