Control of Average pi-Conjugation Length in Main-Chain Conjugated Polymers Prepared via Soluble Precursor Route

采用有机溶剂溶性前驱体法制备了扩展π共轭结构的聚丙烯薄膜。研究了采用扩展π共轭结构制备高质量薄膜的方法。建立了制备四种具有高光学性能的聚苯乙烯薄膜(聚（1,4 -苯基乙烯）、聚（2,3—二甲氧基- 1,4 -苯基乙烯）、聚（7,5 -噻吩乙烯）和聚（2,5 -呋喃基乙烯）的合成方法。在制备具有非常小化学缺陷的前驱体聚合物和从前驱体聚合物到共轭聚合物的转化控制方面的成功，使系统制备具有不同平均共轭长度的样品成为可能。检查聚合物薄膜的紫外可见光谱提供了平均共轭长度的信息，红外光谱提供了确定平均共轭长度的化学缺陷的知识。作为聚（2,5 -乙烯基）模型化合物的低聚物对于识别共轭链上缺陷的结构非常有用。发现顺式乙烯键是结构缺陷之一。了解了前驱体聚合物柔性无序线圈链在转化为刚性线性共轭链时拉伸的重要性。利用转化过程拉伸技术获得了具有高扩展共轭结构的聚合物样品。

Polyarylenevinylene films with extended pi-conjugated structures were prepared via the organic solvent-soluble precursor route. The method to realize high-quality thin films with extended pi-conjugated structures were investigated.1. The synthetic methodology to prepare four polyarylenevinylene films (poly (1, 4-phenylenevinylene), poly (2, 3--dimethoxy-1, 4-phenylenevinylene), poly (7, , 5-thienylenevinylene) and poly (2, 5-furyienevinylene)) with high optical qualities were established.2. The success in both the preparation of precursor polymers with very small chemical defects and the control of conversion from precursor 'Polymer to conjugated polymers enabled the systematic preparation of samples with varied average conjugation lengths. Inspection of UV-visible spectra of polymer films gave the information concerning average conjugation lengths, and IR spectra gave the knowledge on the chemical defects which determined the average conjugation lengths.3. Oligomer compounds which are the model compounds of poly (2, 5thienylenevinylene) were very useful for identifying structures of defects on conjugated chains. The cis-vinylene linkages were found to be one of the structural defects.4. Importance of stretching of flexible random coil chains of precursor polymers, when they are converted to rigid linear conjugated chains were understood. The stretching-during-conversion technique was employed to obtain polymer samples with highly extended conjugated structures.