TexasScholarWorks
    • Login
    • Submit
    View Item 
    •   Repository Home
    • UT Electronic Theses and Dissertations
    • UT Electronic Theses and Dissertations
    • View Item
    • Repository Home
    • UT Electronic Theses and Dissertations
    • UT Electronic Theses and Dissertations
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Exploring chemistry of tetrathiafulvalene-calix[4]pyrroles : supramolecular ion mediated electron transfer

    Thumbnail
    View/Open
    PARK-DISSERTATION.pdf (5.666Mb)
    Date
    2010-12
    Author
    Park, Jung Su
    Share
     Facebook
     Twitter
     LinkedIn
    Metadata
    Show full item record
    Abstract
    Molecular recognition exploiting non-covalent interactions mediates the structure and function of many critical biological and synthetic molecules. There has thus been continuing and intense efforts in the design and synthesis of supramolecular systems with the capability of recognizing specific chemical species. Among various guest species, Prof. Sessler's group has been focused on the study of artificial anion receptors. Calix[4]pyrrole is a tetrapyrrolic macrocycle that is capable of binding anions via concerted and directional hydrogen bonding. Recently, a tetrathiafulvalene (TTF) functionalized calix[4]pyrrole (TTF-C4P) was synthesized and studied as a receptor for various guest species such as anions, electron deficient guest species, and C₆₀. This dissertation focuses on the recent discovery in supramolecular chemistry of TTF-calix[4]pyrrole derivatives. Chapter 1 provides a brief overview of the historical perspective, redox properties, and uses of TTF derivatives as functional building blocks for supramolecular assemblies, as well as previous findings involving the supramolecular chemistry of TTF-C4P. Chapter 2, as the major focus of this dissertation, describes ion mediated supramolecular and reversible electron transfer processes between TTF-C4P and bisimidazolium salts (BIQ²⁺2X⁻). We discovered that the electron transfer processes between these redox couples could be controlled reversibly by ion binding. Specifically, we found that anion binding to the TTF-C4P receptor promotes the forward ET processes. In contrast, cation complexation to the cavity of TTF-C4P causes the reverse ET processes. Such ion mediated ET processes play an essential role in biological ET systems including photosynthesis and respirations. These reversible ET processes were mapped out by spectroscopic (¹H-NMR, UV-Vis NIR titrations, and EPR analysis) and X-ray single crystallographic analyses of both the intermediate and products. Chapter 3 describes the synthesis of aromatic (thiophene and benzene) annulated TTF-calix[4]pyrroles as new and significantly improved receptors for poly-nitroexplosives. The resulting electronic modulations of the parent TTF-pyrrole structure result in significantly enhanced binding affinities for the corresponding TTF-C4Ps toward polynitro-explosives. This is reflected in a high level of positive homotropic allosterism. The degree of the cooperative effect was found to vary depending on the nature of both the receptors and guest species. The origin of the cooperative binding can be explained by conformational locking and an inductive effect of binding the first nitroaromatic guest.
    Department
    Chemistry
    Description
    text
    Subject
    Supramolecular chemistry
    Electron transfer
    Molecular recognition
    URI
    http://hdl.handle.net/2152/ETD-UT-2010-12-2377
    Collections
    • UT Electronic Theses and Dissertations

    University of Texas at Austin Libraries
    • facebook
    • twitter
    • instagram
    • youtube
    • CONTACT US
    • MAPS & DIRECTIONS
    • JOB OPPORTUNITIES
    • UT Austin Home
    • Emergency Information
    • Site Policies
    • Web Accessibility Policy
    • Web Privacy Policy
    • Adobe Reader
    Subscribe to our NewsletterGive to the Libraries

    © The University of Texas at Austin

     

     

    Browse

    Entire RepositoryCommunities & CollectionsDate IssuedAuthorsTitlesSubjectsDepartmentsThis CollectionDate IssuedAuthorsTitlesSubjectsDepartments

    My Account

    Login

    Statistics

    View Usage Statistics

    Information

    About Contact Policies Getting Started Glossary Help FAQs

    University of Texas at Austin Libraries
    • facebook
    • twitter
    • instagram
    • youtube
    • CONTACT US
    • MAPS & DIRECTIONS
    • JOB OPPORTUNITIES
    • UT Austin Home
    • Emergency Information
    • Site Policies
    • Web Accessibility Policy
    • Web Privacy Policy
    • Adobe Reader
    Subscribe to our NewsletterGive to the Libraries

    © The University of Texas at Austin