基于萘嵌苯结构的新型功能化多环芳烃

Extended polycyclic aromatic hydrocarbons (PAHs) system has promising potentials as a new organic functional material in the field of organic electronics, opticals and magnetics. The rylene derivative, a representative family member of PAHs, has good physical characters. However, the design and synthesis of such molecules is very challenging, mainly due to poor solubility and poor stereoselectivity. In this project, we intend to design, prepare and characterise a series of functional molecules on basis of chemically modified rylenes. The molecular materials based on rylenes with novel optoelectronic and magnetic properties are expected. On one hand, perylene with largely conjugated π system can effectively improve the ability of molecular self-assembly, resulting in highly ordered molecules of ortho-functinonalized perylene in both solution and solid states. Thus, this kind of molecule favors to construct a columnar liquid crystals and ferromagnetic materials; On the other hand, quinodial rylene processes unique electronic characteristic. As expanding the π system, the related rylenes not only promote its electronic ground state to be non-bonded π radicals, but also shift its strong absorption to the near-infrared region.

多环芳烃共轭体系作为一种新型的有机功能材料，在有机电子学、光学等领域有着尤其重要的应用前景。其家族成员萘嵌苯衍生物具有优异的特性，但是这类分子的设计与合成非常具有挑战性，主要受溶解性差、立体选择性差和区域选择性差等因素的限制。本项目拟设计、制备及性质研究一系列化学修饰的萘嵌苯功能分子：（1）ortho-位置功能化的二萘嵌苯液晶分子和磁性分子, 其核心π体系能有效地提高分子自组装能力，促使二萘嵌苯碟状液晶和磁性有机分子在溶液和固体状态下有序的堆砌，从而构建柱状液晶和铁磁性材料；（2）醌式萘嵌苯衍生物，醌式结构单元的引入和π共轭体系的扩展，不仅促进其电子基态的改变而出现非成键的π自由基磁学特征，且将其光吸收更大程度的红移。我们期待以萘嵌苯结构为母体，探索和开发一类新型的光电磁性小分子材料。

稠环功能分子的设计与合成非常具有挑战性，主要受溶解性差、立体选择性差和区域选择性差等因素的限制。对高度学科交叉、光电性质融合共生的稠环体系，人们的认识还不够。所以有机合成在稠环化合物构建过程中起到创造者的作用。本项目以具有挑战性的多环芳烃有机功能体系作为目标，设计、合成及性质研究系列可化学修饰的功能分子：1）通过巧妙的氧化螯合剂，使稠环萘发生分子间选择性自由基偶联反应，简易制备苝醌体系。该苝醌体系可化学还原及烷基化修饰，高产率获得溶解性好的新型苝核，并解决了苝类衍生物的ortho-位置功能化修饰难题，为新型苝核体系及多萘嵌苯分子的制备提供了结构基元；2）通过苝醌海湾处羰基与水和肼缩合，简单、高效地制备了螺旋堆积的杂稠化体系，获得氮杂多环芳香功能分子，具备典型的分子内电荷转移、近红外吸收及长波长荧光发射等特性；3）发现苝醌的bay-位羰基基团具有特异的可逆氧化还原性质，其过程具备荧光开闭功能，并应用于可逆荧光探针和活细胞氧化平衡监测；4）构建了醌式构型的功能分子，系统地研究了化合物的光学、电学和磁学等物理性质。本项目也以密度泛函理论和量子化学为辅助手段，研究了稠环芳烃体系的构效关系，并将它们用于解决理论科学问题及应用基础问题。