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dc.contributor.advisorKovacs, Julie A.
dc.contributor.authorBlakely, Maike
dc.date.accessioned2020-02-04T19:25:07Z
dc.date.submitted2019
dc.identifier.otherBlakely_washington_0250E_20993.pdf
dc.identifier.urihttp://hdl.handle.net/1773/45140
dc.descriptionThesis (Ph.D.)--University of Washington, 2019
dc.description.abstractDioxygen activation by non-heme thiolate-ligated Fe-enzymes, such as isopenicillin N synthase (IPNS) and cysteine dioxygenase (CDO) are believed to proceed through several intermediates, including an Fe-superoxo, -hydroperoxo, and high-valent oxo. Thiolate (RS-) ligands are predicted lower the activation barrier to O2 binding, facilitate peroxo O-O bond cleavage via the formation of highly covalent FeIII−SR bonds, and H-atom abstraction reactions. There are few reported examples of well-characterized RS-Fe-superoxo, or -hydroperoxo intermediates. This dissertation describes a new structurally characterized alkyl thiolate-ligated FeII complex, [FeII(S2Me2N3(Pr,Pr)], which reacts with dioxygen (O2) to form an unprecedented example of a reactive RS-FeIII-superoxo intermediate The kinetics of formation of the thiolate ligated FeIII-superoxo intermediate [FeIII(S2Me2N3(Pr,Pr)(O2)] formed via the addition of O2 to [FeII(S2Me2N3(Pr,Pr)], and the addition of potassium superoxide (KO2) to [FeIII(S2Me2N3(Pr,Pr)]+, are presented. This RS-FeIII-superoxo intermediate goes on to cleave strong C-H bonds converting to a second observable intermediate, proposed to be an FeIII-hydroperoxo, en route to a rare example of a crystallographically characterized η2-coordinated sulfenate (RSO-) complex. A look into the mechanism of the formation of the rare stable sulfenate was carried out using oxo atom donors added to the oxidized [FeIII(S2Me2N3(Pr,Pr)]+. The formation of oxo atom donor adducts is observed in these reactions at low temperatures, which then convert to the singly oxygenated sulfenate. This implicates a metal-mediated pathway for sulfur oxygenation, as opposed to direct attack at the sulfur, and possibly an unobservable FeV-oxo as the active oxidant. Finally, synthetic routes to new alkyl-thiolate ligated Fe complexes are discussed due to their potential to expand our understanding of how thiolates influence reactivity.
dc.format.mimetypeapplication/pdf
dc.language.isoen_US
dc.rightsnone
dc.subjectBioinorganic
dc.subjectInorganic chemistry
dc.subject.otherChemistry
dc.titleInsights into Dioxygen Activation by Biomimetic Alkyl Thiolate-Ligated Iron Complexes
dc.typeThesis
dc.embargo.termsDelay release for 1 year -- then make Open Access
dc.embargo.lift2021-02-03T19:25:07Z


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