acase@tulane.edu / Nano-spaces are ubiquitous in Nature and are of high interests among supramolecular chemists. Understanding molecular behaviors within nano-space can offer new perspectives on biological phenomena in Nature, opens the way to highly unusual and selective forms of catalysis, and offers new approaches to separation protocols via molecular protection. Our own studies involve synthetic cavitands that can provide well-defined nano-spaces with novel and unusual physicochemical properties. In an effort of further understanding the properties of monomeric cavitands and their dimeric complexes, the encapsulation of different series of guests as well as the effects encapsulation has on them will be discussed.
First, the binding of saturated and unsaturated fatty acids to deep-cavity cavitand octa-acid (OA) has been examined. The complexes formed between the former and OA showed a transition from 1:1 to 2:1 host-guest complex, and revealed details about guest-packing motif and the need for carboxylate protonation for formation of the 2:1 capsular complex. The guest motif mapping of the latter and their methyl esters was discussed. The results demonstrated how such mapping can be used to identify heterogeneities within the supramolecular capsule formed by dimerization of OA.
Second, the dimeric capsules of OA and and its positively charged equivalent (P1) were used as templates for controlling macrocyclization processes occurring within their interior. The binding of 11 guests (of varying length) bearing bromide/chloride and thioacetate/thiol group at the termini of the alkyl chain inside both OA was studied in detail. The binding motif (Linear, J-shaped and Reverse J-shaped) of the guests and the opposite electrostatic potential generated by P1 and OA have shown distinct effect on the cyclization reaction.
Finally, encapsulation of a series of alcohol, aldehyde and alkene homologues to OA was examined and how the guest properties control their susceptibility to oxidation by exogenous, solution-based reagents KMnO4 was revealed. The reactivity of encapsulated guests was found to be correlated with their binding affinity with OA. / 1 / Kaiya Wang
| Identifer | oai:union.ndltd.org:TULANE/oai:http://digitallibrary.tulane.edu/:tulane_77511 |
| Date | January 2017 |
| Contributors | Wang Kaiya (author), Gibb Bruce (Thesis advisor), School of Science & Engineering Chemistry (Degree granting institution) |
| Publisher | Tulane University |
| Source Sets | Tulane University |
| Language | English |
| Detected Language | English |
| Type | Text |
| Format | electronic, 192 |
| Rights | 12 months, Copyright is in accordance with U.S. Copyright law. |
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