With support from the Organic Dynamics program of the Chemistry Division, Professor Angel E. Kaifer of the University of Miami (Florida) will study the electrochemistry of supramolecular systems, especially rotaxanes, dendrimers, and host-guest systems. This is a continuation of previously funded work (CHE-9304262) which showed that electron transfer reactions and proton transfer reactions can be used to switch certain rotaxanes between conformers having different electronic absorption spectra. The present project will involve investigation of the thermodynamics and kinetics of electron transfer involving such supramolecular architectures, the preparation of new rotaxane systems, and continuation of fundamental investigations of binding, structure, and intermolecular forces in host-guest systems. The electron transfer reactions are selected for special emphasis. The project will include work intended to lead to facile preparation of supported monolayers containing preformed binding sites. The monolayers chosen for emphasis are amine functionalized receptors on carboxylate terminated self-assembled monolayers. This project will prepare some of the groundwork for the use of certain chemical compounds as `molecular switches,` molecules which respond in some observable way to external stimuli such as light or electricity. The work may eventually be useful in nanotechnology, since it leads to new materials with the potential for molecular level information storage and processing. Work with self-assembled monolayers may lead to selective molecular sensors.
