This research program targets extended molecular capsules to address fundamental questions in physical organic chemistry and to develop novel supramolecular materials. Specific goals of the proposal are: a) preparing and characterizing new multicomponent hydrogen bonded assemblies; b) understanding the dynamics of self- and hybrid assembly processes; and c) exploring the use of these assemblies as molecular devices, delivery systems, organocatalysts and smart materials.
With the support of this EAGER award from the Macromolecular, Supramolecular, and Nanochemistry Program, Professor Julius Rebek, of the Skaggs Institute for Chemical Biology at The Scripps Research Institute is exploring the synthesis and properties of molecules that completely surround other molecules. Such arrangements represent unique phases of matter in chemistry and lead to materials with potentially broad technological applications. This project serves as an excellent training ground for students in fundamental research because it exposes them to broad experiences in organic synthesis, compound characterization, spectroscopy, as well as issues in chirality, data storage and nanotechnology. This project will have an important impact on society because it will permit the Principal investigator to host, mentor and cultivate talented high school teachers and devise research plans for future high school student and teacher internships. These internships provide the early steps in the education of the nations future professors of chemistry.
The scientific basis for this grant was the study of molecules in very small spaces. We call these small spaces "capsules" and they completely surround the molecules held inside. Typically, molecules enjoy large spaces in the liquid or gas phase where they can move, spin and tumble freely. In the capsules there is frequently only space for one or two molecules inside, and present a very challenging environment. Some of the fundamental scientific questions deal with how molecules get in and out of these capsules; what is the phase inside - gas, liquid, or solid; how do molecules inside communicate with those outside; what determines the arrangement of molecules in the space and can it be controlled? From these encapsulation complexes, it has emerged that the behavior of small molecules inside is different from behavior of molecules free to move around in solution. Instead, molecules in encapsulation complexes behave very much like molecules at the active sites of enzymes and other biological receptors, so a connection exists with the biological world as well. The capsules are the most realistic "models" for enzymes. In the past two years, we have been able to make new capsule containers that are indefinitely stable. This allows their use in aqueous solutions and their attachment to surfaces. One of the goals has been to grow containers layer-by-layer on these surfaces with each layer representing information. The intention is to provide data storage at the sub-nano scale. Another application that has been accomplished in the funding period is the use of the container molecules to detect molecules in biofluids such as human plasma and urine. The goal here is to safely sense, detoxify and destroy molecules that pollute the environment.
