Thermodynamically Driven (Reversible) End-Capping of Pseudorotaxanes to Produce Rotaxanes

Simple item page
dc.contributor.authorFletcher, Amy L.en
dc.contributor.committeechairGibson, Harry W.en
dc.contributor.committeememberWard, Thomas C.en
dc.contributor.committeememberMcGrath, James E.en
dc.contributor.departmentChemistryen
dc.date.accessioned2014-03-14T20:30:19Zen
dc.date.adate2004-01-15en
dc.date.available2014-03-14T20:30:19Zen
dc.date.issued2003-08-29en
dc.date.rdate2005-01-15en
dc.date.sdate2004-01-09en
dc.description.abstractRotaxanes can be synthesized using a thermodynamically driven approach of self-assembly. The thermodynamically driven approach is an efficient method to provide a better controlled synthesis of specific structures. This synthetic approach takes advantage of a labile bond between the guest molecule and the end stopper group. The reversibility of this bond allows for threading by the host molecule via chemical equilibrium. Intramolecular interactions such as hydrogen bonding and π-π stacking facilitate threading to form the pseudorotaxane which is endcapped to form the thermodynamically stable rotaxane. In this work, the synthesis and characterization of rotaxanes using a thermodynamically driven approach is reported. New OH-functionalized secondary dibenzyl ammonium hexafluorophosphate and tetrafluoroborate salts were synthesized and complexed with dibenzo-24-crown-8. The complexation between the salts and dibenzo-24-crown-8 was observed using 1D and 2D ¹H NMR spectroscopy. An association constant of 110 M⁻¹ was determined by integration for the pseudorotaxane from the ammonium hexafluorophospate salt and dibenzo-24-crown-8. The new guest species were endcapped in situ as trityl ethers to form new thermodynamically stable rotaxanes. Further work to pursue would include synthesis of rotaxanes using functionalized crown ethers for polymerization to make polyrotaxanes and synthesis of self-assembled polymers using this synthetic method.en
dc.description.degreeMaster of Scienceen
dc.identifier.otheretd-01092004-112614en
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-01092004-112614/en
dc.identifier.urihttp://hdl.handle.net/10919/30864en
dc.publisherVirginia Techen
dc.relation.haspartALF-thesis.pdfen
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subjectSupramolecular Chemistryen
dc.subjectSelf-Assemblyen
dc.subjectPseudorotaxaneen
dc.subjectRotaxaneen
dc.titleThermodynamically Driven (Reversible) End-Capping of Pseudorotaxanes to Produce Rotaxanesen
dc.typeThesisen
thesis.degree.disciplineChemistryen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.levelmastersen
thesis.degree.nameMaster of Scienceen

Files

Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
ALF-thesis.pdf
Size:
4.27 MB
Format:
Adobe Portable Document Format
Download

Collections

Masters Theses