Collaborative Research: RUI: Manipulation of Arylene Ethynylene Structures and Properties via Coordination, Halogen Bonding and Hydrogen Bonding

美国国家科学基金会化学部的大分子、超分子和纳米化学计划支持这一项目，设计和合成新的碳基分子，用于灵活、高性能的电子设备。对这些分子的研究可能会使人们更好地理解如何设计理想的特性以及这些材料是如何发挥作用的。例如，控制共轭单体、齐聚物和聚合物中分子构象的能力不仅对操纵它们的电子性质很重要，而且对优化材料的整体电子性质也很重要。虽然材料中的自由旋转可能会导致各种不可预测的、甚至是不受欢迎的分子堆积排列，但实施平面性的策略可以提供更多的有序性和增强的电子性质。因此，构象受限的芳撑乙炔是发展光伏、薄膜晶体管和发光器件的重要目标。同样，由于其刚性和可预测的几何形状，芳纶乙炔结构可以作为特定大小和形状的客人的东道主。完全了解和优化这些系统的几何参数可能会带来新的传感能力。负责合成和表征这些新化合物的本科生在实验室获得了实践经验，为他们在化工行业的职业生涯或研究生课程的进一步学习做好了准备。该项目在威斯康星大学史蒂文斯分校和密苏里州立大学两个不同的校区进行。来自这些校区的教授参与有意义的研究，不仅提高了直接参与研究项目的学生的教育，也提高了学生在课堂上从知识和技能传授中受益的教育。该项目的科学目标是设计和制备具有允许分子水平控制电子性质、晶体设计和主客体活动的新型芳撑结构。具体地说，在共轭体系中引入吡啶基团提供了通过卤素键、氢键和过渡金属配位进行结构控制的机会。这些相互作用为生成新型液晶、增强不饱和主链的有效共轭和高度特异性的主客体配对提供了途径。

The Macromolecular, Supramolecular and Nanochemistry Program of the NSF Division of Chemistry supports this project to design and synthesize new carbon-based molecules for potential use in flexible, high performance electronic devices. The study of these molecules may lead to a better understanding of how to design desirable properties as well as how these materials function. For example, the ability to control molecular conformations in conjugated monomers, oligomers, and polymers is not only important for manipulating their electronic properties, but also for optimization of the bulk electronic properties of a material. While free rotation within a material can lead to a variety of unpredictable, and perhaps undesirable, molecular packing arrangements, strategies for enforcing planarity can provide increased order and enhanced electronic properties. Arylene ethynylenes that are conformationally constrained are, therefore, important targets in the development of photovoltaic, thin-film transistor and light emitting devices. Similarly, with their rigidity and predictable geometries, arylene ethynylene structures can serve as hosts for guests of specific sizes and shapes. Complete understanding and optimization of the geometric parameters of these systems may lead to new sensing capabilities. Undergraduates responsible for synthesizing and characterizing these novel compounds gain hands-on experience in the laboratory, preparing them for careers in chemical industry or additional study in graduate programs. This project is conducted on two different campuses, University of Wisconsin-Stevens Point and Missouri State University. The participation of professors from these campuses in meaningful research enhances the education of not only the students working directly on the research projects, but also students who benefit from the transfer of knowledge and skills in the classroom.The scientific objective of this project is to design and prepare novel arylene ethynylene structures with features that allow molecular level control over electronic properties, crystal design, and host-guest activity. Specifically, incorporation of pyridinyl groups within conjugated systems offers an opportunity for structural control via halogen bonding, hydrogen bonding, and transition metal coordination. These interactions provide avenues for the generation of novel liquid crystals, the enhanced effective conjugation of unsaturated backbones, and highly specific host-guest pairing.