染料聚合物的合成和超分子组装

In this project, we will synthesize crown ethers-, spermines-containing amphiphilic dye molecules by covalent attachment of hydrophilic crown ether or positively charged spermine groups to hydrophobic perylene core at the imide positions, and explore their self-assembly behavior, and further synthesize their supramolecular polymers by cofacial pi-pi interaction. Core-twisted perylene dyes will be synthesized by four aromatic substitutes at bay position. Core-twisted perylene dye molecules can suppress and interfere with pi-pi interaction within supramolecular polymers, thus will be used as chain iniferter, to obtain living/controlled supramolecular polymerization. We further study the recognition ability of these supramolecular polymers to biologically relevant alkali metal cations Na+, K+, Zn2+, Mg2+, and explore their application potentials as fluorescence sensors.. We will design and synthesize various perylene-containing macromolecular systems, and investigate their self-organization behavior. We will study their photochemical and photophysical properties, especially photo-induced electron transfer, which is aimed at exploring their application potentials. Perylene dye monomer with polymerizable acrylic double bonds will be synthesized in this project. Controlled / living radical polymerization, i.e. atom transfer radical polymerization, will be used to synthesize well-defined perylene dye homopolymers with controlled chain length and narrow polydispersity. Carbazole donor monomer will be synthesized, then polymerized, and the carbazole homopolymer further initiate perylene dye acceptor monomer to obtain donor/acceptor block copolymer. The donor or acceptor dye chain length (molecular weight) could be tailored by atom transfer radical polymerization to tune their superstructures. . The chemical structures of the block copolymers will be fully characterized by 1H , 13C and 2D NMR spectroscopy, IR spectroscopy, MALDI-TOF mass spectrometry. For the block copolymers, the carbazole donor chain can be regarded as coil block, and dye acceptor chain can be regarded as rod block, and thus, the copolymers are rod-coil architectures. Their self-assembly behavior, phase morphologies will be investigated by transmission electron microscope and atomic force microscope and scanning electron microscopy. The photochemical and photophysical properties of the dye block copolymers will be investigated by UV/vis absorption spectroscopy, steady-state, and time-resolved fluorescence spectroscopy. The well-defined superstructures, and macroscopic morphologies, nano- and mesoscopic phase separation of n-type (perylene bisimide block) and p-type (carbazole block) within copolymers will favor photoinduced charge separation and transport, and exciton diffusion, to give excellent optoelectronic properties. We will calculate the energy level of highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO), the free energy change and rate of photoinduced electron transfer in the block copolymers according to the redox potential measured from cyclic voltammetry. The advantages of this block copolymers for their desirable optoelectronic properties are as follows: one step solution-processable self-assembly, high molar absorption coefficients in the visible range that match the solar spectrum, an energy band gap between dye acceptor and carbazole donors is suitable for efficient charge carrier generation, and favorable charge transport due to the highly ordered superstructures. The block copolymers will have the potentials in photovoltaic applications.

本项目将合成含精胺或冠醚基团的两亲染料分子，通过共面pi-pi等非键弱相互作用，合成染料超分子聚合物，使用非平面核扭转的染料分子作为链转移终止试剂，研究超分子聚合物活性生长。使用透射电子显微镜, 原子力显微镜等表征手段，获得超分子聚合物的分子水平的高分辨图像，观测研究超分子聚合物的形态，尺寸和长度。研究超分子聚合物对重要的生物信息阳离子钠, 钾, 锌, 镁等，识别能力和灵敏度。使用原子转移自由基聚合方法，合成窄分子量分布，可控链长度的染料均聚合物，通过控制染料均聚合物的链长，调节均聚合物的形态。合成含咔唑给体的单体，其聚合的咔唑链段继续引发染料单体聚合，形成咔唑柔性给体链段，染料刚性受体链段的嵌段共聚物。通过调节刚柔两段的长短，来调节其组装形态，实现给受体较大的接触面，形成有效的P-N结，测试其光诱导电子转移等光电性能。这类染料共聚物具有机光伏材料应用潜力。

染料超分子聚合物骨架中非共价键的存在，使得这类分子的聚合和解聚可以很容易的发生，这赋予了这类化合物独特的机械、电子以及光学性质。本项目按照预定计划开展了研究工作，完成了三类（含有P-型三苯胺、咔唑或N-型苝酰亚胺等功能色团）两亲性染料分子的超分子组装和聚合物的合成与表征，而且对三类两亲性染料超分子聚合物的光电性质，发光性质、电化学性质、超分子组装和聚合性质等进行了细致且系统的研究。使用透视电子显微镜, 原子力显微镜等手段获得超分子聚合物的分子水平的高分辨图像，研究这些功能染料超分子组装体及聚合物的形态，尺寸和长度。通过单晶的培养、原位在线核磁检测、二维核磁共振技术、动态光散射、圆二色光谱，紫外，荧光光谱研究这些功能染料超分子组装体和超分子聚合物的光诱导电子转移等光电性能，荧光共振能量转移，和超分子聚合和单体增长过程。为这些功能染料超分子聚合物在荧光高敏识别、光电材料、光伏器件等方面的应用和开发提供了研究基础。