(66c) Separations From Pharmaceuticals to Fuels Using Grafted Calixarenes as Designed Adsorbents
Calixarenes are cavity-containing small molecules often suggested to be useful for separations. When functionalized with solubilizing groups or when attached to solid surfaces, these compounds can be applied in selective extractions or adsorption. Here, results are presented along two directions. In the first, semi-empirical modeling studies are used to advance the understanding of extraction of positively changed, amphipathic amide amine drugs using strongly negatively charged water-soluble calixarenes. In the second area, calixarenes are examined for the uptake of dipolar molecules such alcohols from aqueous solution. Insight from semi-emperical modeling is compared to materials synthesized by covalent attachment of calixarenes to solid supports. Calixarenes of different ring substituents, bridging groups, and attachment points are examined. The attachment of the calixarene is described and the resulting hybrid organic-inorganic materials are characterized primarily by TGA and UV-visible. Uptake onto solid adsorbents is measured by depletion of bulk solution followed by gas chromatography or spectrophotometric titration.