Synthesis and Self-Assembly of New Polycyclic Aromatic Hydrocarbons

基于共轭芳族化合物的材料显示出用于下一代有机电子器件的潜力，包括显示器和太阳能电池。这些材料的设计需要调节分子特性的能力，以及控制分子如何在诸如结晶固体或液晶的介质中组织和定位的能力。拟议的研究使用合成有机化学来制备新的多环芳香族化合物，这些化合物旨在以可预测的方式进行自组装，并旨在了解分子结构如何影响这种自组装。最终，这项研究计划将为指导新功能材料的设计提供见解。在未来五年，该研究计划将集中在三个主要领域： (i)由多环芳烃（PAHs）和外围柔性烷基侧链组成的“U”形分子可以形成柱状液晶相。我们的研究已经检查了分子结构的修饰如何影响液晶性质。基于我们以前的工作，我们将设计基于缺电子多环芳烃和大圆盘形分子的新型柱状液晶分子，以探索结构修饰对液晶性质的影响。此外，我们将制备化合物，可以作为分子构建块的扩展，共价连接的框架建设。 (ii)与上述平面盘形分子相反，非平面芳族化合物通常不能有效地堆叠，并且与其他类型的分子（包括富勒烯或碳纳米管）进行分子间相互作用。我们将制备新的非平面芳香族化合物，并探索它们结合小分子的能力，如缺电子芳香族化合物和富勒烯。例如，我们将制备具有较大多环芳香族单元的四亚苯基的扩展版本，形成具有能够结合其他分子的独特空腔的化合物，例如TNT和富勒烯等小芳香族化合物。 (iii)我们发现，邻苯二酚衍生物与邻苯二甲腈的亲核芳香取代反应可以制备新的发光液晶化合物。我们已经扩展了这种方法，将其他杂原子在这些多环系统，并已证明，杂原子取代有显着的影响，固态组织和发光。使用我们的方法，我们将专注于功能材料的制备，如有机电子学的电子接受材料。 我们还将使用这种方法来制备更复杂的结构，其中笨拙的分子形状阻止了有效的包装。 这些材料可以作为多孔分子固体用于小分子的封装、气体储存或催化。

Materials based on conjugated aromatic compounds show potential for the next generation of organic electronic devices, including displays and solar cells. Design of these materials requires the ability to tune molecular properties, as well as the ability to control how molecules are organized and positioned in media such as crystalline solids or liquid crystals. The proposed research uses synthetic organic chemistry to prepare new polycyclic aromatic compounds that are designed to self-assemble in predictable ways and aims to understand how molecular structure affects this self-assembly. Ultimately, this research program will provide insight to guide the design of new functional materials. Over the next five years, the research program will focus on three main areas: (i) Disk-shaped molecules composed of polycyclic aromatic hydrocarbons (PAHs) and peripheral flexible alkyl side chains can form columnar liquid crystal phases. Our studies have examined how modifications to molecular structure affect liquid crystalline properties. Based on our previous work, we will design new columnar liquid crystalline molecules based on electron-deficient PAHs and large disk-shaped molecules to probe the effect of structural modifications on liquid crystalline properties. In addition, we will prepare compounds can serve as molecular building blocks for the construction of extended, covalently linked frameworks. (ii) In contrast to the planar disk-shaped molecules described above, non-planar aromatic compounds often do not stack as effectively and engage in intermolecular interactions with other types of molecules, including fullerenes or carbon nanotubes. We will prepare new non-planar aromatic compounds and explore their ability to bind small molecules such as electron-deficient aromatic compounds and fullerenes. For example, we will prepare extended versions of tetraphenylenes with larger polycyclic aromatic units, forming compounds with a distinct cavity that is capable of binding other molecules, such as small aromatic compounds like TNT and fullerenes. (iii) We have shown that new luminescent liquid crystalline compounds can be prepared by nucleophilic aromatic substitution reactions of tetrafluoroterephthalonitrile with catechol derivatives. We have extended this methodology to incorporate other heteroatoms in these polycyclic systems and have demonstrated that heteroatom substitution has a dramatic impact on solid state organization and luminescence. Using our methodology, we will focus on the preparation of functional materials such as electron accepting materials for organic electronics. We will also use this approach to prepare more complex architectures where awkward molecular shape prevents effecting packing. These materials may serve as porous molecular solids for the encapsulation of small molecules, gas storage, or catalysis.