含活性酯的共轭聚合物的后修饰反应与功能化研究

发布时间：2018-04-18 09:32

  本文选题：聚(双取代乙炔) + 聚合后修饰　； 参考：《浙江大学》2017年博士论文

【摘要】：在自然界中,每一个物种都是经过进化且适应新的环境而存在的。在物种进化的过程中,遗传物质(DNA和RNA,少许蛋白质)决定了其外在性状的表达。生物教科书告诉我们,在基因的重组或变异只关乎碱基对的增、减和序列的改变,而无关其主链结构。尽管热力学上最终状态是稳定的,但是由小分子聚合成大分子需要消耗高能量,同时由小分子连接成高分子量聚合物带来的熵减小效应也与自发过程违和。于是,自然界演化出用相对单一的主链结构通过多种侧基组合来改变和丰富大分子功能的策略。目前,荧光聚合物材料在电致发光与太阳电池器件、化学传感、生物成像等领域备受关注,而光电功能高分子的合成均采取通过改变单体结构来调控聚合物功能的策略。换言之,每当我们想调节一种共轭聚合物的结构和功能,都需要从头合成,这和自然选择的策略大相径庭。本论文工作结合课题组在聚炔领域的前期工作基础,师法自然,考虑到聚(二苯基乙炔)和聚(对苯乙炔撑)的衍生物具有良好的发光性能,以这两类荧光聚合物为前驱体,通过引入活性反应中心,从而实现对聚合物进行后修饰和功能化的目的。我们首先将含有五氟苯酯的双取代炔烃单体在WCl6和Ph4Sn的催化作用下聚合得到聚合物前驱体。五氟苯的拉电子效应活化了酯基,使其在温和条件下与伯胺/仲胺亲核试剂进行反应。聚合物前驱体与炔丙胺反应得到含有端炔的次级聚合物前驱体。进而采用叠氮小分子与次级聚合物前驱体进行点击反应,最终得到了侧基含有三唑的双取代聚炔。两步后修饰反应均具有反应温和、高效、完全的特点。此外,得到的聚合物均具有黄绿色的荧光和较高的量子效率。其次,继续以含活性酯的双取代聚炔为前驱体,成功地制备了双取代聚炔侧链含有伯胺、叔胺的二级聚合物前驱体。在此基础之上,具有功能化的氧化石墨烯/双取代聚炔杂化体成功制备,具有调控聚合物及杂化体荧光发射波长的特点,我们将这一现象解释为共平面诱导发射红移;含有叔胺的双取代聚炔一方面由于质子化作用,表现出pH的响应行为,另一方面可以继续衍生得到含有两性离子的双取代聚炔,表现出一定的水溶性。在制备的含两性离子双取代聚炔具有水溶性后,我们接着又利用后修饰策略分别制备了含阳离子、阴离子的两种二苯基聚乙炔的衍生物,分别比较了三种含离子型的双取代聚炔的水分散情况,其水分散能力为:含两性离子的双取代聚炔含阴离子的双取代聚炔含阳离子的双取代聚炔。我们进一步研究了三种离子型聚炔的荧光强度与浓度的关系。在较低浓度时,三种的聚合物荧光强度与浓度保持线性关系;而浓度过高时,出现荧光强度增加变缓和荧光下降情况两种情况。综合分析,链内激子的形成是两性离子型双取代聚炔高浓度下荧光猝灭的主要原因。偶氮苯是具有光学活性的官能团,我们利用活性酯策略成功制备了含有偶氮苯衍生物的双取代聚炔,并与之前报道的单取代偶氮苯聚炔的性质进行比较。研究发现,二者在紫外灯的照射下均表现出光致异构化的行为,且光致异构化行为与聚合物的主链位阻效应有着联系。利用更高能量的紫外光(254nm)可以实现偶氮苯从顺式到反式的回复。除此之外,含偶氮苯的双取代聚炔其聚集荧光行为与母体聚合物有着截然相反的效果,前驱体聚炔表现为聚集增强荧光(AEE),而修饰后的双取代聚炔表现为聚集猝灭荧光(ACQ),偶氮苯具有荧光淬灭的效果,这也为荧光行为调控提供了简便的方法。手性侧基将手性传递到双取代聚炔的主链已取得成功,以往的研究关注的是含有对映异构体的手性侧基在圆二色谱上会呈现对应的康顿信号和手性聚炔表现出偏振荧光发射。我们通过活性酯路线修饰了含较大手性侧基后发现,除圆二色谱外,对映异构体修饰的聚合物在反应现象、反应程度、溶解性等方面都有较大差异,理论模拟优化的结构显示L型的空间结构满足形成分子内氢键的要求,而D型不可以,结构上的差异导致了后续性能的区别。最后,采用Sonogashira偶联聚合得到活性酯修饰的对苯乙炔与四苯基乙烯(TPE)的交替共聚合物。聚合物具有聚显著的AEE行为,且在不同的混合溶剂体系中荧光增强阈值也不同。通过引入手性分子,手性可以实现传导至主链,并使聚合物表现出“手性放大”效应;PEG分子链的引入则可以实现聚合物的亲疏水性调控,将接PEG前后的聚合物在接触角和扫描电镜的测试中均有明显的区别。此外,这类荧光聚合物在爆炸物的超放大检测中有着优异的效果。
[Abstract]:In nature, each species is evolved and adapted to the new environment and exist. In the process of the evolution of species, genetic material (DNA and RNA, a protein) determines its traits. The expression of biological textbooks tell us, in genetic recombination or mutation only about base pairs, reduction and sequence changes, regardless of its backbone structure. Although thermodynamically final state is stable, but by small molecules aggregated into large molecules need to consume high energy, at the same time by small molecules connected into a high molecular weight polymer has effects of reducing the entropy and spontaneous process molimen. Then evolved with the backbone structure is relatively simple through a variety of side groups combined to change and enrich the molecular function strategy. At present, the fluorescent polymer electroluminescent and solar cell devices in electrical, chemical sensing, biological imaging and other areas of concern, and the light Synthesis of functional polymer electric were taken by changing the monomer structure to control polymer functional strategies. In other words, when we want to adjust the structure and function of a conjugated polymer, which requires de novo synthesis, and natural selection strategy. This thesis be quite different with the nature of work based on our previous work, polyacetylene in the field, taking into account the poly (two phenyl acetylene) and poly (phenylene ethynylene) derivatives have good luminescent properties, the two kinds of fluorescent polymers as precursors by introducing active reaction center, so as to achieve the purpose of modification and functionalization of the polymer. We will contain five fluoro ester disubstituted alkyne monomer in the catalysis of WCl6 and Ph4Sn under the polymerization of polymer precursor. Five - electron withdrawing ester activation effect, make it under mild conditions with primary amine / secondary amine nucleophiles The reaction. The polymeric precursor and propargylamines reaction of secondary polymer precursor containing alkyne azide. Then the small molecules and secondary polymer precursors were click reaction, finally got the double side group containing three triazole substituted polyacetylenes. The two step after the modification reaction has mild reaction, efficient, complete. In addition, the quantum efficiency of the polymers obtained have high fluorescence and the yellow green. Secondly, to substituted polyacetylenes as precursor containing active ester, the successful preparation of disubstituted polyacetylenes containing side chain amine was prepared. The two stage polymerization precursors of tertiary amines. On this basis, with functionalized graphene oxide / disubstituted polyacetylenes hybrid was prepared successfully, and has the characteristics of control of polymer hybrid fluorescence emission wavelength, we explained the phenomenon as a co planar induced emission redshift; containing tertiary amine bis substituted polyacetylenes On the one hand, due to protonation, showed the response behavior of pH, on the other hand can be derived containing zwitterionic disubstituted polyacetylenes, exhibit certain water solubility. In preparation containing amphoteric disubstituted polyacetylenes with water soluble, we then use after modification strategies respectively the preparation of cation containing two phenyl, two anionic polyacetylene derivatives were compared respectively containing three kinds of ionic disubstituted polyacetylenes dispersed in water, the water dispersion ability: containing zwitterionic disubstituted polyacetylenes containing anionic disubstituted polyacetylenes containing cationic double substituted polyacetylenes. The relationship between fluorescence intensity and concentration we further study the three kinds of ionic polyacetylene. At low concentration, a linear relationship between the three kinds of polymer fluorescence intensity and concentration; and the concentration is too high, the fluorescence intensity increases moderate fluorescence appeared decrease situation two Cases. Comprehensive analysis, formation of intrachain exciton is the main reason of amphoteric disubstituted polyacetylenes in high concentrations. The fluorescence quenching of azobenzene groups is optically active, we use the active ester strategy was successfully prepared containing azobenzene derivatives disubstituted polyacetylenes, and compared with previously reported single substituted azobenzene polyacetylene properties. The study found that the two under the irradiation of UV lamp showed the photoisomerization behavior and the photoisomerization behavior and polymer backbone steric effect associated with higher energy. Using ultraviolet light (254nm) can be achieved from cis to trans azobenzene in reply. In addition, the azobenzene containing double substituted polyacetylenes and their aggregation behavior of fluorescence matrix polymer has the opposite effect, the precursor of polyacetylene exhibits aggregation enhanced fluorescence (AEE), and modified disubstituted polyacetylenes as poly In the fluorescence quenching (ACQ), azobenzene with fluorescence quenching effect, which is fluorescent behavior control provides a simple and convenient method. Chiral side group transferred to the chiral disubstituted polyacetylenes backbone has been successful, the previous study is concerned with the chiral side group enantiomer will appear in the corresponding circle two the Condon chromatographic signal and chiral polyacetylene exhibits polarization fluorescence emission. We modified with larger chiral side groups by active ester route after the discovery, in addition to round two chromatography, enantiomeric modification of the polymer in the reaction, the reaction degree, solubility and other aspects have great differences, the structure of the simulation optimization theory the display space structure of L type of intramolecular hydrogen bonding, while type D can not, structural differences lead to different follow-up performance. Finally, polymerization active ester modified 1,4-phenylenevinylene with Sonogashira coupling Four phenyl ethylene (TPE) alternating copolymer. Polymers with poly AEE behavior significantly, and in the mixed solvent system in different fluorescence enhancement threshold is different. Through the introduction of chiral molecules and chiral can transfer to the main chain, and the polymer showed "chiral amplification effect"; the introduction of PEG molecular chain can be achieved hydrophobicity control of polymer, polymer before and after PEG will pick both in the contact angle and the scanning electron microscope test significant difference. In addition, this kind of fluorescent polymers have excellent efficacy in ultra zoom explosive detection.

【学位授予单位】：浙江大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：O631
，

本文编号：1767796