Photochemical generation of electron poor reactive intermediates: Photochemistry of S-alkoxy dibenzothiphenium tetrafluoroborates, N-alkoxy pyridinium perchlorates, and Sulfonium ylides

dc.contributor.advisor William S. Jenks
dc.contributor.author Kolattoor, Jagadeesh
dc.contributor.department Chemistry
dc.date 2021-01-16T18:22:14.000
dc.date.accessioned 2021-02-25T21:38:40Z
dc.date.available 2021-02-25T21:38:40Z
dc.date.copyright Tue Dec 01 00:00:00 UTC 2020
dc.date.embargo 2020-12-04
dc.date.issued 2020-01-01
dc.description.abstract <p>Photolysis of thiophene ylides such as dibenzothiophene ylide (DBTY) and 2,5-dichlorothiophene ylide (DCTY) provides a route to certain carbenes with adjustable photophysical parameters, in that the absorption spectrum of the precursor and the initial spin population of the carbene can be varied. However, the accumulated thiophene from extensive photolysis can act as a triplet sensitizer leading to the generation of relatively high proportion of triplet carbene. It is demonstrated that dibenzothiophene has this property and 2,5-dichlorothiophene does not.</p> <p>S-alkoxy dibenzothiophenium and N-alkoxy pyridinium salts are prepared and photolyzed to explore the potential homolytic and heterolytic paths of the photochemical S-O cleavage of the thiophenium salts. The heterolytic path would generate a highly unstable electron-deficient alkyl oxenium ion and the corresponding neutral leaving group. Homolysis would generate an alkoxy radical and the corresponding radical cation of the leaving group. The evidence obtained suggests the homolytic formation of alkoxy radical and radical cation of the leaving group though some fraction of the oxenium and the neutral leaving group cannot be ruled out completely.</p>
dc.format.mimetype application/pdf
dc.identifier archive/lib.dr.iastate.edu/etd/18341/
dc.identifier.articleid 9348
dc.identifier.contextkey 21104775
dc.identifier.doi https://doi.org/10.31274/etd-20210114-76
dc.identifier.s3bucket isulib-bepress-aws-west
dc.identifier.submissionpath etd/18341
dc.identifier.uri https://dr.lib.iastate.edu/handle/20.500.12876/94493
dc.language.iso en
dc.source.bitstream archive/lib.dr.iastate.edu/etd/18341/Kolattoor_iastate_0097E_19240.pdf|||Fri Jan 14 21:40:36 UTC 2022
dc.subject.keywords Dibenzothiophene triplet sensitizer
dc.subject.keywords Dicarbomethoxy 2,5-dichlorothiophene ylide (DCTY)
dc.subject.keywords Dicarbomethoxy dibenzothiophene ylide (DBTY)
dc.subject.keywords N-alkoxy pyridinium perchlorate
dc.subject.keywords Photolysis
dc.subject.keywords S-alkoxy dibenzothiophenium tetrafluoroborate
dc.title Photochemical generation of electron poor reactive intermediates: Photochemistry of S-alkoxy dibenzothiphenium tetrafluoroborates, N-alkoxy pyridinium perchlorates, and Sulfonium ylides
dc.type article
dc.type.genre thesis
dspace.entity.type Publication
relation.isOrgUnitOfPublication 42864f6e-7a3d-4be3-8b5a-0ae3c3830a11
thesis.degree.discipline Organic Chemistry
thesis.degree.level thesis
thesis.degree.name Doctor of Philosophy
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