CAREER: Novel Conjugated Macromolecules from Fused Heterocyclics and from Oxidative Solid-state Crosslinking

University Of Connecticut, Storrs CT

Investigators

Abstract

Professor Gregory A. Sotzing of the Institute of Materials Science at the University of Connecticut is supported by the Organic and Macromolecular Chemistry Program to study the polymerization of fused five-membered bicyclics for the preparation of conjugated polymers. Having three sites of polymerization within these monomers allows a rigorous study of differently linked linear conjugated polymers. Professor Sotzing proposes to separately block each one of the alpha sites of the fused bicyclics in order to prepare regio-irregular and regio-regular polymers. Of significant merit will be a study of the differences in conjugation. For example, polymerization through two positions of the fused five-membered bicyclics will produce linear conjugated polymers containing a locked cisoid conformation whereas polymerization through two different positions on the same monomer will produce linear conjugated polymers containing unique locked transoid conformations. The effect of regioregularity on the optical and electronic properties of the polymers will also be probed. Due to multiple conjugation pathways and the geometric locations of the three alpha sites, these fused bicyclics will be used for the preparation of novel conjugated macrocycles for possible use as molecular conductors, molecular ordering on gold, and metal binding applications. In a separate study, Professor Sotzing will explore the use of electrochemical atomic force microscopy (ECAFM) coupled to his solid-state crosslinking procedure as a method to generate conjugated polymer nanowires. This study will involve a fundamental examination of the coupling process as it pertains to precursor polymer structure, polymer swelling, and oxidation potential. With the support of the Organic and Macromolecular Chemistry Program Professor Sotzing will contribute to an understanding of different pathways for conjugation in the materials studied and determine if intrinsic conductivity can exist through multiple pathways of a branch point. This could lead to future developments and a better understanding of molecular electronics. By writing conductive polymer nanowires and understanding this new writing technique, the research could, in the future, lead toward tools to nanopattern optoelectronics and other nanoscale devices such as transistors and sensors. Collaborative research will be performed at the Air Force Research Laboratory (AFRL) studying the above-mentioned materials in photovoltaic devices. This highly interdisciplinary research tied to a center of excellence for applications, AFRL, will foster an environment of learning and creativity for both graduate and undergraduate students. Within the proposed period, electronic nose experiments will be incorporated into the high school laboratory curriculum in order to educate secondary level students in the field of electronic devices and how sensors are an essential component of homeland security. This project will give the high school students a broader understanding of how chemistry is intimately connected to technology on a fundamental level.