November 5, 2003FRONTIERS IN MATERIALS SCIENCE
VINSE COLLOQUIUM SERIES
Dr. Miguel Garcia-Garibay
Department of Chemistry and Biochemistry
University of California, Los Angeles
"Molecular Compasses and Gyroscopes: Design, Preparation, and Testing"
Abstract. The field of artificial molecular machines represents an exciting new branch of nanotechnology. Molecular machines have been defined as chemical structures that undergo mechanical motions (output) in response to programmable stimuli (input). To accomplish their function, molecular machines rely on an assemblage of parts that transmit forces, motion, or energy, from one to another in a structurally predetermined manner. Examples reported in the literature include molecular propellers, gears, turnstiles, ratchets, etc., all of which are only “functional” as isolated entities and in dilute solution. Our interests in the organic solid state have motivated us to look for compounds that may experience programmable motions in close-packed crystalline media. Inspired by macroscopic devices and biomolecular machines, we suggest that compounds displaying volume-conserving rotary motions will be the best candidates. This seminar will describe our research efforts on the design and preparation of crystalline solids built with molecules that can emmulate compasses and gyroscopes. Like the two navigational machines, the desired structures are characterized by having a rigid framework that shields a reorienting or rotating dipole that is capable of responding to external electro-magnetic fields and/or to external forces which cause a change in its angular momentum. In addition to the basic science associated with their preparation and the assessment of the desired functions, molecular compasses and gyroscopes offer a new approach to the design of electrooptic materials for a wide range of photonic applications. This seminar will describe the design, synthesis, crystallization, solid state dynamics, and materials properties of several structures. 3,4
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 Dominguez, Z.; Khuong, T.-A. V.; Dang, H.; Sanrame, C. N.; Nunez, J. E.; Garcia-Garibay, M. A. J. Am. Chem. Soc. 2003, 125, 8827-8837.
 Khuong, T.-A. V.; Zepeda, G.; Ruiz, R.; Khan, S. I.; Garcia-Garibay, M. A. Cryst. Growth Des. 2003, 3, Web Release Date: October 16, 2003.