Toward Mesoscale Order in Multicomponent Organic Thin Films via Hydrogen Bond Directed Supramolecular Topology

通过这个奖项，大分子、超分子和纳米化学项目支持罗纳德·卡斯特拉诺教授和他在佛罗里达大学的合作者研究半导体碳基（有机）材料。对于许多下游应用-显示器，照明，太阳能电池，晶体管和传感器-加工薄（10-1,000纳米）薄膜中有机分子的三维（3-D）排列决定了器件的性能。这项研究正在开发一种通用的自组装方法，允许功能有机分子以自我引导的方式形成有用的上层结构。在最广泛的意义上，这项工作有助于对如何在纳米/中尺度上控制单组分和多组分有机物的三维结构的一般理解。在教育和培训方面，更广泛的影响来自(1)研究生和本科生接触到多学科科学，包括合成和物理有机化学、光谱学、计算、材料处理/表征和设备制造；(2)学生参与者与佛罗里达大学化学俱乐部一起，向K-8教室传播符合标准的实验模块，这些模块包含化学/材料科学的概念和他们自己的研究；(3)扩大弱势群体在STEM研究活动中的参与。虽然已知如何定制单个π共轭分子的电子和光学性质以及如何编程分子在溶液中的排列，但其使用的主要瓶颈是预测和控制薄膜中的三维形态结构。本研究探讨了一种基于氢键的分层自组装方法，在pi共轭低聚物薄膜中创建纳米级到中观尺度的秩序，而不考虑pi发色团的结构。该设计包括将典型的pi共轭组分共价连接到能够将其超分子组装成可预测形状的聚集体的分子识别单元。所得到的拓扑结构有望独特地支持薄膜共混物中适当形状的添加剂的自然分离，并允许实现理想的光电性能。提出的自下而上的自组装方法有效地将有机半导体薄膜的形态结构与组成pi共轭发色团的固有光电结构解耦，允许这些方面通过合理/理论指导的材料设计独立优化。该合作项目的具体目标包括pi共轭低聚物的模块化设计和合成，溶液和薄膜中的光电结构和（超）分子排序的评估，以及使用诊断设备表征薄膜中的光电特性和批量排序。

With this award the Macromolecular, Supramolecular and Nanochemistry Program supports Professor Ronald Castellano and his collaborators at the University of Florida to study semiconducting carbon-based (organic) materials. For many downstream applications - displays, lighting, solar cells, transistors, and sensors - the three-dimensional (3-D) arrangement of organic molecules in processed thin (10-1,000 nanometer) films dictates device performance. This study is developing a general self-assembly approach to allow functional organic molecules to form useful superstructures in a self-guided way. In the broadest sense, the work contributes to a general understanding of how to control the 3-D structure of single and multi-component organic matter at the nano-/mesoscale. Broader impacts with respect to education and training come from (1) graduate and undergraduate students being exposed to multidisciplinary science that includes synthetic and physical organic chemistry, spectroscopy, computation, materials processing/characterization, and device fabrication; (2) the student participants, together with the UF Chemistry Club, disseminating standards-aligned experimental modules to K-8 classrooms that embed concepts of the chemical/materials sciences and their own research; and (3) broadening the participation of underrepresented groups in STEM research activities. While it is known how to tailor the electronic and optical properties of individual pi-conjugated molecules as well as to program the arrangements of the molecules in solution, a major bottleneck for their usage is predicting and controlling three-dimensional morphological structure in thin films. This research examines a hierarchical self-assembly approach based on hydrogen bonding to create nanoscale to mesoscale order in thin films of pi-conjugated oligomers irrespective of pi-chromophore structure. The design involves covalently linking typical pi-conjugated components to molecular recognition units capable of directing their supramolecular assembly into predictably shaped aggregates. The resulting topologies are expected to uniquely support the natural segregation of appropriately shaped additives in thin film blends, and allow desirable optoelectronic properties to be achieved. The proposed bottom-up self-assembly approach effectively decouples the morphological structure of organic semiconductor thin films from the intrinsic optoelectronic structure of the constituent pi-conjugated chromophores, allowing these aspects to be independently optimized through rational/theory-guided material design. The specific aims of this collaborative project include modular design and synthesis of pi-conjugated oligomers, evaluation of optoelectronic structure and (supra)molecular ordering in solution and in thin films, and characterization of the optoelectronic properties of and bulk ordering within the thin films using diagnostic devices.