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DC Field | Value | Language |
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dc.contributor.advisor | Childs, R.F. | en_US |
dc.contributor.author | Weigl, Stefan | en_US |
dc.date.accessioned | 2014-06-18T16:36:38Z | - |
dc.date.available | 2014-06-18T16:36:38Z | - |
dc.date.created | 2010-06-07 | en_US |
dc.date.issued | 1988-06 | en_US |
dc.identifier.other | opendissertations/2016 | en_US |
dc.identifier.other | 2884 | en_US |
dc.identifier.other | 1346296 | en_US |
dc.identifier.uri | http://hdl.handle.net/11375/6708 | - |
dc.description.abstract | <p>This thesis describes a study of the photosolvolysis of N-benzoyl-5-bromo-7-nitroindoline. The investigation was instigated because N-acyl-5-bromo-7-nitroindolines have been considered as potential photoprotecting groups for the photolithographic formation of charge-mosaic membranes. However, no kinetic data, and only scant mechanistic information, has been reported for the photofragmentation process.</p> <p>Both absorption and emission spectra of N-benzoyl-5-bromo-7-nitroindoline were obtained. Based on the electronic spectra, it would seem that the two lowest energy singlet excited states are nearly isoenergetic and their relative energies are a function of the solvent medium.</p> <p>The distribution of photoproducts obtained from irradiation of N-benzoyl-5-bromo-7-nitroindoline in various solvent systems was investigated. It was shown that the photosolvolysis reaction is a function of the solvent properties. Thus 5-bromo-7-nitroindoline and benzoic acid were the only photoproducts formed in acetonitrile. In acetonitrile-water, 5-bromo-7-nitrosoindole as well as 5-bromo-7-nitroindoline and benzoic acid were identified. A correlation between solvent polarity, Eᴛ(30), and 5-bromo-7-nitrosoindole formation was observed.</p> <p>The mechanism of the fragmentation mode was examined. The presence of a free radical intermediate is suggested from the photoproduct distribution in tetrahydrofuran (THF). Observation of an electron spin resonance (e.s.r.) spectrum during irradiation of N-benzoyl-5-bromo-7-nitroindoline in an e.s.r. spectrometer cavity, 180 incorporation into benzoic acid, and a linear free energy relationship with sigma dot (δ·) corroborated the intermediacy of a free radical in the fragmentation process.</p> <p>Quantum yields of N-benzoyl-S-bromo-7-nitroindoline disappearance in different solvents and quenchers were measured in order to establish the reactive excited state and the effect of the medium on the efficiency of the transformation process. A solvent dependency on both the excited state lifetime and photosolvolysis reaction efficiency was noted. The results were indicative of a change in mechanism with a variation in solvent polarity and/or hydrogen bonding ability.</p> <p>A mechanism compatible with experimental results and applicable to previously reported N-acyl-2-nitroaniline photofragmentations is proposed.</p> | en_US |
dc.subject | Chemistry | en_US |
dc.subject | Chemistry | en_US |
dc.title | Photosolvolysis of N-Benzoyl-5-bromo-7-nitroindoline (A Mechanistic Study) | en_US |
dc.type | thesis | en_US |
dc.contributor.department | Chemistry | en_US |
dc.description.degree | Doctor of Philosophy (PhD) | en_US |
Appears in Collections: | Open Access Dissertations and Theses |
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fulltext.pdf | 8.52 MB | Adobe PDF | View/Open |
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