Folding polyrotaxanes using secondary noncovalent bonding interactions

ORGN 414

Wenyu Zhang, wyzhang@chem.ucla.edu1, William R. Dichtel, wdichtel@chem.ucla.edu1, Adam Stieg1, Diego Benitez, diego@chem.ucla.edu1, James K. Gimzewski1, James R. Heath, heath@caltech.edu2, and J Fraser Stoddart, stoddart@chem.ucla.edu1. (1) Department of Chemistry and Biochemistry, University of California, Los Angeles, 405 Hilgard Avenue, Los Angeles, CA 90095-1569, (2) Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125
Mechanically interlocked molecules, such as catenanes, rotaxanes and knots1 have recently found increasing use in the construction of sophisticated molecular devices, which are key components for nanoelectromechanical systems (NEMS) and molecular electronic devices (MEDs).2 The elaboration of the mechanically interlocked structure to polymers might allow the utilization of molecular motion to impact bulk material properties. Template-directed syntheses via the copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC)3 has enabled us to synthesize mechanically interlocked structures with high convergence and efficiency.4 Recent research progress (Box) on the synthesis of polymers with interlocked π-electron donating and accepting constitutions using the CuAAC methodology will be reported. We have developed polyrotaxanes that adopt a folded structure by virtue of incorporating alternating strongly and weakly binding monomers, which thread through or stack on the exterior, respectively, of π-electron accepting tetracationic CBPQT4+ cyclophanes. Our fundamental studies on the properties of these systems, as well as the exploitation of their properties for nanoelectromechanical and molecular electronic applications are ongoing. (1) Sauvage, J. P.; Dietrich-Buchecker, C.; Molecular Catenanes, Rotaxanes and Knots: A Journey through the World of Molecular Topology; Wiley VCH: Weinheim, 1999. (2) (a) Green, J. E.; Choi, J. W.; Boukai, A. Bunimovich, Y.; Johnston-Halperin, E.; Delonno, E.; Luo, Y.; Sheriff, B. A.; Xu, K.; Shin, Y. S.; Tseng, H.-R.; Stoddart, J. F.; Heath, J. R. Nature 2007, 445, 415–417. (b) Dichtel, W. R.; Heath, J. R.; Stoddart, J. F. Phil. Trans. R. Soc. London Ser. A. 2007, 365, 1607–1625. (3) (a) Dichtel, W. R.; Miljanic, O. S.; Spruell, J. M.; Heath, J. R.; Stoddart, J. F. J. Am. Chem. Soc. 2006, 128, 10388–10390. (b) Miljanic, O. S.; Dichtel, W. R., Mortezaei, S., Stoddart, J. F. Org. Lett. 2006, 8, 4835–4838. (4) Rostovtsev, V. V.; Green, L. G.; Fokin, V. V.; Sharpless, K. B. Angew. Chem. Int. Ed. 2002, 41, 2596–2599.

 

Heterocycles and Aromatics, Molecular Recognition and Self Assembly
8:00 PM-10:00 PM, Tuesday, April 8, 2008 Morial Convention Center -- Hall A, Poster

Division of Organic Chemistry

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008