American Chemical Society 64th Regional Meeting
October 1 - 4, 2008
Barron Group Abstracts
FULLERENE DERIVATIZED AMINO ACIDS: SYNTHESIS BY DIPOLAR ADDITION OF AZIDO AMINO ACIDS
Amanda Strom and Andrew R. Barron, Department of Chemistry, Rice University, Houston, Texas 77005
Two new bifunctional fullerene amino acids have been prepared by dipolar addition of an N?-protected, azido amino acid to the fullerene cage. Azide derivatives of phenylalanine and lysine were prepared as the starting materials. Without a catalyst, yields were approximately 30 %, comparable to literature reports for azide additions to C60. With the addition of a copper (I) catalyst, the yields were almost doubled. Deprotection of the Boc and Fmoc derivatives resulted in the water soluble, parent amino acid. In addition, both derivatives readily undergo coupling with NH2-Gly-OtBu indicating their ability for incorporation into a peptide sequence.
Olefin Coordination by Copper (I) Complexes of N-Aryl Dipyridylamines
Christopher E. Hamilton, a John J. Allen, a Michael F. Lynch, b Robert C. Schucker, b and Andrew R. Barron. a
(a) Rice University Department of Chemistry, Houston TX, (b) Trans Ionics Corporation, The Woodlands, TX.
Copper (I) olefin complexes are of great interest for a number of reasons. ETR 1, a hormone receptor that regulates many aspects of plant development and growth, contains an ethylene-binding Cu(I) center. Additionally, copper compounds are active catalysts for alkene transformations including hydrogenation, cyclopropanation, and polymerization. Copper (I) complexes of chelating aromatic N-heterocycles preferentially bind olefin isomers in the order: terminal > internal cis > internal trans . Thus, these compounds can be exploited to separate desired alkenes from mixtures thereby avoiding energy-intensive cryogenic distillation. N-aryl dipyridylamines and diquinolylamine ligands were prepared. Their Cu(I) complexes were then used to bind various olefins. Products were characterized by single crystal X-ray diffraction and 1 H and 13 C NMR.
Eoghan Dillon, Christopher Crouse, Colm Craven and Andrew Barron, Rice University, Houston, TXThe solubility of single-wall carbon nanotubes (SWNTs) in aqueous and organic solvents is a difficult barrier that must be overcome to allow for potential applications in the biomedical and material sciences. Previous work involving the addition of polymers towards the dissolution of SWNTs has focused on the covalent attachment of polymers to the carboxylic acid moieties found at the open ends of SWNTs or the physical adsorption of polymers or surfactants on the sidewalls. In this work the reaction between branched-polyethyleneimine (PEI) and uncut, fluorinated-SWNTs (F-SWNTs) was performed yielding the covalent attachment of the polymer to the sidewalls of the nanotubes. These results were confirmed through solid state NMR, Raman spectroscopy, XPS, UV-vis and TGA studies. The resulting PEI functionalized SWNTs (PEI-SWNTs) are shown to have an increased solubility in aqueous media. The synthesis, characterization, carbon dioxide absorption potential and possible biomedical applications of the newly formed PEI-SWNTs will be discussed.
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