Doctor of Philosophy (PhD)
The synthesis and properties of some macrocyclic compounds of interest are presented. Resorcinarenes with functionalized conjugated rigid rods made of oligo-p-phenylenes would lead to an entirely new class of functional, soluble, well-defined architectures impacting a variety of multidisciplinary research efforts. The general synthetic design described in this document could be readly extrapolated to include other electronic systems such as heteroaromatics and polyenes. An extensive collaborative study of chromophore formation in resorcinarene solutions is also described here. The study reveals that upon oxidation, the reversible conversion to acyclic precursors occur first, and then these precursors undergo oxidation to quinoid-type compounds (xanthenes). The understanding of the mechanism of chromophore formation allowed us to design selective receptors for carbohydrates and the development of post-column selective reagents for the detection of mono- and oligosaccharides. This latter work is still in progress and the preliminary studies are described here. In another study involving macrocyclic architectures, tiliacorinine, an alkaloid, which consists of five rings forming a macrocycle exhibits a rare H-H spin coupling in its 1H NMR. Molecular modeling was used to determine the spatial relationship between the protons involved. Fluorinated [2,2]p-cyclophanes have been attracting increased attention. Poly(p-xylylene) polymers are materials of current technological interest. An obstacle to the commercialization of these polymers is the multistep syntheses required to obtain the fluorinated monomers. We describe a two-step synthesis of the tetrafluoro[2,2]p-cyclophanes. Another family of compounds, the fullerenes, was studied. Authors of a recent communication about the isolation and characterization of what was called the "missing" isomer of C60O postulated that this isomer could be present during the epoxidation of C60. Our HPLC and 1H NMR studies of the epoxidation of C60 revealed that there is no other isomer besides the epoxide in the photooxigenation of C60.
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Escobedo Cordova, Jorge O., "Synthesis and properties of novel macrocycles and related chromophoric benzenoid compounds" (2002). LSU Doctoral Dissertations. 1238.
Robert M. Strongin