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I. Photochemical studies of phenoxy radical. II. The photorecation of Michler's ketone with benzophenone

Citation

Wamser, Carl C. (1970) I. Photochemical studies of phenoxy radical. II. The photorecation of Michler's ketone with benzophenone. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/390h-jd89. https://resolver.caltech.edu/CaltechETD:etd-02272009-093235

Abstract

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I. Photochemical studies of phenoxy radical: Phenoxy radical was generated by flash photolysis of aqueous phenol. The ultraviolet-visible absorption spectrum of phenoxy radical was obtained. Decay kinetics for the bimolecular disappearance of phenoxy radical led to a second order rate constant of k[...] = 1.2 ± 0.1 x [...] sec[...]. In these solution-phase flash photolysis studies, no evidence was obtained for further decomposition of phenoxy radical. Molecular orbital symmetry correlations demonstrate that the conversion of phenoxy radical to cyclopentadienyl radical and carbon monoxide is symmetry-allowed from the ground state and symmetry-forbidden from the excited state of phenoxy radical.

II. The photorecation of Michler's ketone with benzophenone: Michler's ketone (4,4'-bis[dimethylamino]benzophenone) undergoes a photoreaction with benzophenone in 2-propanol to give photoproduct I with moderate quantum efficiency. This product arises from the coupling of benzophenone [...] ketyl radical with the corresponding radical derived from Michler's ketone. Each of these photointermediates was characterized by the absorption spectra and decay kinetics obtained from flash photolysis studies. The key mechanistic step must be transfer of hydrogen from the triplet state of Michler's ketone to benzophenone, and is without precedent in photochemistry. A triplet "exciplex" is postulated to lead to the hydrogen transfer.

Item Type:Thesis (Dissertation (Ph.D.))
Degree Grantor:California Institute of Technology
Division:Chemistry and Chemical Engineering
Major Option:Chemistry
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Hammond, George Simms
Thesis Committee:
  • Unknown, Unknown
Defense Date:2 September 1969
Record Number:CaltechETD:etd-02272009-093235
Persistent URL:https://resolver.caltech.edu/CaltechETD:etd-02272009-093235
DOI:10.7907/390h-jd89
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:793
Collection:CaltechTHESIS
Deposited By: Imported from ETD-db
Deposited On:06 Mar 2009
Last Modified:16 Apr 2021 23:33

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