功能手性高分子的合成与性质研究

发布时间：2018-03-08 00:33

  本文选题：手性高分子　切入点：聚集诱导发光效应　出处：《南京大学》2014年硕士论文　论文类型：学位论文

【摘要】：手性是自然界普遍存在的现象。作为生命结构基本单元的氨基酸和核酸中的核糖几乎分别都是L-和D-构型,在分子的水平上实现了对称性的破缺。这种不对称分子是生命的物质基础,光学活性是生命有序化和组织化的基础。圆偏振荧光(CPL)是源于手性发色团体系的左手性和右手性圆偏振光的选择性发射。手性高分子在溶液中呈孤立的单分子分布,在聚集态下则以聚集体的形式存在,手性高分子这种不同的存在形式会对其CPL产生影响。手性高分子中手性单元的存在会对高分子的堆积方式和电子分布方式产生影响,并且有利于分子内相互缠绕和扭曲,有利于发生能量传递。本论文研究工作分为两个部分,一是基于四苯乙烯的手性高分子的合成及其聚集诱导发光效应和圆偏振荧光性能研究；二是手性稀土铕高分子合成及其在“通过键能”能量转移和荧光量子产率调控方面的研究。第二章,通过单体1,2-二(4-乙炔基苯基)-1,2-二苯乙烯与单体3’,5’-二碘-N-a-叔丁氧羰基-O-辛基-L-酪氨酸甲酯的Sonogashira偶联反应合成了基于四苯乙烯(TPE)的手性高分子TPETyr。有趣地是,该手性高分子在其良溶剂THF中发射弱的荧光,但当加入水之后,便形成了纳米粒子悬浮物,能够发射出较强的荧光,展示出一种新颖的聚集诱导发光现象(AIE)。无论是在THF溶液中还是在聚集态下手性高分子TPETyr均具有较大的CPL不对称因子(glum)。更重要的是,glum表现出环境应激性,其值可通过改变THF中水的含量来调控,从0.44到0.08。第三章,首次合成了以(R,R)-1,2-环G二胺为手性源的三种新颖的手性高分子,这三种手性高分子分别与Eu(TTA)3·2H2O反应得到相应的稀土高分子P-2、P-4和P-6,通过光谱分析发现稀土高分子P-2、P-4和P-6中手性高分子与Eu(TTA)3之间发生了键能传递。并且,稀土高分子P-2、P-4和P-6均具有较大的斯托克斯位移(△λmax=265nm)和发光光谱的红移(△λmax=214nm)。此外,稀土高分子P-2、P-4和P-6的荧光量子产率是模板化合物Model的60-100倍,且荧光量子产率的值可通过稀土高分子中亚甲基连接单元的长短来调控,从3.01%到5.30%。
[Abstract]:Chirality is a common phenomenon in nature. The amino acids and ribosomes in nucleic acids, which are the basic units of life structure, are L- and D-, respectively. At the molecular level, symmetry is broken. This asymmetric molecule is the material foundation of life. Optical activity is the basis of life ordering and systematization. Circular polarization fluorescence (CPL) is derived from the selective emission of left-handed and right-handed circular polarized light from chiral chromophore systems. In the aggregate state, the chiral polymer exists in the form of aggregates, and the existence of chiral polymers has an effect on their CPL. The existence of chiral units in chiral polymers will have an effect on the stacking and electron distribution of the polymers. This paper is divided into two parts, which are conducive to intermolecular entanglement and distortion, and to the generation of energy transfer. The first is the synthesis of chiral polymers based on tetrastyrene and their aggregation induced luminescence and circularly polarized fluorescence properties. The second is the synthesis of chiral rare earth europium polymer and its study on the energy transfer through bond energy and the regulation of fluorescence quantum yield. The chiral macromolecule TPETyr based on tetrastyrene was synthesized by the Sonogashira coupling reaction of monomeric 1h2- dioxynylphenyl-1 ethynylphenyl-1-distyrene with the monomer 3H _ (5N) -diiodo-N-a- (tert-butylcarbonyl) -O _ (-octyl) -tyrosine methyl ester. Interestingly, the chiral macromolecule TPETyr based on tetrastyrene (TPE) was synthesized. The chiral polymer emits weak fluorescence in its good solvent THF, but when water is added, the suspensions of nanoparticles are formed, which can emit strong fluorescence. A novel phenomenon of agglomeration induced luminescence has been demonstrated. Both in THF solution and in aggregated TPETyr, TPETyr has a large CPL asymmetry factor, and more importantly, it shows environmental stress. Its value can be controlled by changing the content of water in THF, from 0.44 to 0.08. in Chapter 3, three novel chiral polymers were synthesized, which were chiral source. The three chiral polymers reacted with Eu(TTA)3 路2H2O to obtain the corresponding rare earth polymers P-2P4 and P-6.The bond energy transfer between the chiral polymers P-2P4 and P-6 and Eu(TTA)3 was found by spectroscopic analysis. Both P-2P4 and P-6 have a large Stokes shift (位 max-265nm) and a red shift of luminescence spectra (位 max-214nm). In addition, the fluorescence quantum yields of the rare earth polymers P-2P4 and P-6 are 60-100 times higher than those of the template compound Model. The fluorescence quantum yield can be controlled by the length of methylene bonding units in rare earth polymers, ranging from 3.01% to 5.30.
【学位授予单位】：南京大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：O631
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本文编号：1581674