rdf-syntax-grammar
mods:
  schema location: http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
  title info:
    non sort: A
    title: study of some reactions containing radical intermediates
  name:
    name part: Varick, Thomas Robert
    name part: 1964-
    role:
      role term: creator
  name:
    name part: Newcomb, Martin
    role:
      role term: degree supervisor.
  name:
    name part: Singleton, Daniel
    role:
      role term: degree supervisor.
  name:
    name part: Hall, Ken
    role:
      role term: degree committee member.
  name:
    name part: Harding, Kenn
    role:
      role term: degree committee member.
  name:
    name part: Sulikowski, Gary
    role:
      role term: degree committee member.
  name:
    name part: Texas A & M University
    role:
      role term: degree granting institution.
  type of resource: text
  genre: bibliography
  genre: Academic theses
  origin info:
    place:
      place term: xx
    date issued: 1991
    issuance: monographic
  language:
    language term: eng
  physical description:
    form: print
    extent: xi, 81 leaves : illustrations ; 29 cm
  abstract: The reduction of trityl halides by lithium dialkylamide bases in THF produces high yields of triphenylmethane and a small amount of trityl dimer. Studies were conducted to investigate the mechanism of this reaction. Kinetic studies were conducted for the reaction of trityl chloride with lithium diisopropylamide and lithium tert-butylethylamide in THF at -78 °C, and these studies suggest that the reaction is first order in both monomeric base and trityl chloride. Deuterated amide bases were used for inter- and intramolecular kinetic isotope effect studies which demonstrated that a rate determining formation of a reaction complex preceded a hydrogen atom transfer step from the amide base to the trityl species. These results were coupled with other kinetic information to formulate a scheme for the reactions. The reactions proceed by a rapid dissociation of trityl halide which leads to the formation of a triytl-THF oxonium cation in the basic THF solvent. The amide base is present in a slow equilibrium between monomeric and dimeric forms, but the monomer is the reactive species. An associative complex is formed by a rate limiting electron transfer process between the monomeric base and the trityl-THF oxonium ion. Within this reactive complex, a fast hydrogen atom transfer between aminyl radical and trityl radical produces the observed triphenylmethane product. The hydrogen atom transfer step competes to a small extent with radical escape from the reaction complex, which ultimately leads to the production of trityl dimer. The acyl derivatives of N-hydroxypyridine-2-thione are used as radical precursors for obtaining kinetic information for reactions which proceed through radical intermediates. This method was used to measure rate constants for the ring opening of the trans-(2-phenylcyclopropyl)carbinyl radical from -48 to 25 °C in toluene. An Arrhenius function was found to be log k = 13.7 - 3.24/2.3 RT, and a rate constant for the ring opening was calculated to be 1.9x1…
  note: Typescript (photocopy).
  note: Vita.
  note: "Major subject: Chemistry."
  note: Ph. D. Texas A & M University 1991
  note: Includes bibliographical references.
  subject:
    topic: Free radical reactions
  subject:
    topic: Charge exchange
  subject:
    topic: Reduction (Chemistry)
  subject:
    topic: Major chemistry
  identifier: http://proxy.library.tamu.edu/login
  related item:
    location:
      url: http://proxy.library.tamu.edu/login
  record info:
    record content source: TXA
    record creation date: 921223
    record change date: 20200904152606.0
    record identifier: in00001110316
    language of cataloging:
      language term: eng