With this renewal award, the Organic and Macromolecular Chemistry Program continues its support for the work of Professor Frederick D. Lewis of the Department of Chemistry at Northwestern University in Evanston, IL. The research will continue investigations of the interaction of light with organic molecules. Photochemical rearrangements of styrene derivatives, involving an initial photocyclization to a high energy ground state species that undergoes a thermal hydrogen migration to yield a stable aromatic product, will be studied. The potential energy surface along which these reactions proceed will be probed by measuring the kinetics and thermodynamics of both the thermal and photochemical steps. Molecules with geometries designed to undergo facile photochemical rearrangement will be synthesized. The data resulting from these studies will be fundamental to the understanding of the role of energetics in low barrier isomerizations. Photochemical and photophysical investigations designed to elucidate the nature of intramolecular interactions in diarylureas and polyarylureas will be carried out. Since these molecules adopt unusual folded structures in which adjacent aryl groups have a face-to-face geometry, they are ideal model systems for investigating phenomena such as charge transfer and electron transport in molecular systems.
These studies are expected to have broad impact upon fundamental understanding of electron transport in organic molecules. Such information will contribute to the basis for the construction of molecular wires and devices. The research will also provide valuable training for students at both the undergraduate and graduate levels.
