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

University Of Wisconsin-Stevens Point, Stevens Point WI

Investigators

Abstract

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.