While transition metal complexes are known to participate in multi-electron redox chemistry to facilitate important organometallic transformations, actinides, due to their low redox potentials, have a propensity to perform single electron chemistry. Because of its highly reducing nature, the ability to control the electronics of low-valent uranium is highly sought after as this may lead to unprecedented reactivity. Our lab has specifically been interested in mediating multi-electron transformations at uranium by employing redox-active ligands. Redox-active ligands can be used to facilitate multi-electron processes such as oxidative addition and reductive elimination at single metal centers. Using primarily 2,6-((Mes)N=CMe)2C5H3N) ( MesPDIMe) as a redox-active ligand, highly reduced uranium species bearing bulky cyclopentadienyl-based ancillary ligands, CpxU (MesPDIMe)(L) (x = P (1-(7,7-dimethylbenzyl)), * (1,2,3,4,5-pentamethyl); L = THF, HMPA), have been synthesized. These species have the ability to perform one, two, and four electron reduction of a variety of substrates. For examples, uranium mediated pinacol coupling of carbonylated substrates as well as oxidative addition toward two (X2, PhE-EPh, PhE-X) and four electron (Ar-N=N-Ar’, oxygen-atom transfer reagents) organic oxidants have been studied. with both radical and concerted addition pathways operable. Synthesis of a trans-dioxo species, Cp*UO2(MesPDIMe), has allowed for the study of the activation of the robust U=O double bonds—providing key insights into the necessary components for U=O bond scission. The lessons learned from the reductive silylation of this complex redox-active ligand species has allowed for application of these principles to simple UO 22+ systems.
","abstract_html":"<p>While transition metal complexes are known to participate in multi-electron redox chemistry to facilitate important organometallic transformations, actinides, due to their low redox potentials, have a propensity to perform single electron chemistry. Because of its highly reducing nature, the ability to control the electronics of low-valent uranium is highly sought after as this may lead to unprecedented reactivity. Our lab has specifically been interested in mediating multi-electron transformations at uranium by employing redox-active ligands. Redox-active ligands can be used to facilitate multi-electron processes such as oxidative addition and reductive elimination at single metal centers. Using primarily 2,6-((Mes)N=CMe)2C5H3N) ( MesPDIMe) as a redox-active ligand, highly reduced uranium species bearing bulky cyclopentadienyl-based ancillary ligands, CpxU (MesPDIMe)(L) (x = P (1-(7,7-dimethylbenzyl)), * (1,2,3,4,5-pentamethyl); L = THF, HMPA), have been synthesized. These species have the ability to perform one, two, and four electron reduction of a variety of substrates. For examples, uranium mediated pinacol coupling of carbonylated substrates as well as oxidative addition toward two (X2, PhE-EPh, PhE-X) and four electron (Ar-N=N-Ar’, oxygen-atom transfer reagents) organic oxidants have been studied. with both radical and concerted addition pathways operable. Synthesis of a <em>trans</em>-dioxo species, Cp*UO2(MesPDIMe), has allowed for the study of the activation of the robust U=O double bonds—providing key insights into the necessary components for U=O bond scission. The lessons learned from the reductive silylation of this complex redox-active ligand species has allowed for application of these principles to simple UO 22+ systems.</p>","abstract_has_math":false,"creators":["Kiernicki, John J."],"institution":null,"degree_name":"Doctor of Philosophy (PhD)","degree_level":"Dissertation","degree_discipline":"Chemistry","degree_department":null,"school":null,"contributors":["Suzanne C. Bart","Mingji Dai","David R. McMillin","Tong Ren"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2016,"date_issued":"2016-12-01T08:00:00Z","date_published":"2016-12-01T08:00:00Z","updated_at":"2026-07-24T03:54:09Z","subjects":["Pure sciences","Redox-active ligands","Uranium","Chemistry","Inorganic Chemistry"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://docs.lib.purdue.edu/open_access_dissertations/955","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Suzanne C. Bart","Mingji Dai","David R. 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Because of its highly reducing nature, the ability to control the electronics of low-valent uranium is highly sought after as this may lead to unprecedented reactivity. Our lab has specifically been interested in mediating multi-electron transformations at uranium by employing redox-active ligands. Redox-active ligands can be used to facilitate multi-electron processes such as oxidative addition and reductive elimination at single metal centers. Using primarily 2,6-((Mes)N=CMe)2C5H3N) ( MesPDIMe) as a redox-active ligand, highly reduced uranium species bearing bulky cyclopentadienyl-based ancillary ligands, CpxU (MesPDIMe)(L) (x = P (1-(7,7-dimethylbenzyl)), * (1,2,3,4,5-pentamethyl); L = THF, HMPA), have been synthesized. These species have the ability to perform one, two, and four electron reduction of a variety of substrates. For examples, uranium mediated pinacol coupling of carbonylated substrates as well as oxidative addition toward two (X2, PhE-EPh, PhE-X) and four electron (Ar-N=N-Ar’, oxygen-atom transfer reagents) organic oxidants have been studied. with both radical and concerted addition pathways operable. Synthesis of a trans-dioxo species, Cp*UO2(MesPDIMe), has allowed for the study of the activation of the robust U=O double bonds—providing key insights into the necessary components for U=O bond scission. The lessons learned from the reductive silylation of this complex redox-active ligand species has allowed for application of these principles to simple UO 22+ systems.
"]},{"key":"dc:title","label":"Title","values":["Redox-active ligand uranium complexes for approaches to multi-electron chemistry"]}]}],"canonical_facts":{"dc:contributor":["Suzanne C. Bart","Mingji Dai","David R. McMillin","Tong Ren"],"dc:creator":["Kiernicki, John J."],"dc:description.abstract":["While transition metal complexes are known to participate in multi-electron redox chemistry to facilitate important organometallic transformations, actinides, due to their low redox potentials, have a propensity to perform single electron chemistry. Because of its highly reducing nature, the ability to control the electronics of low-valent uranium is highly sought after as this may lead to unprecedented reactivity. Our lab has specifically been interested in mediating multi-electron transformations at uranium by employing redox-active ligands. Redox-active ligands can be used to facilitate multi-electron processes such as oxidative addition and reductive elimination at single metal centers. Using primarily 2,6-((Mes)N=CMe)2C5H3N) ( MesPDIMe) as a redox-active ligand, highly reduced uranium species bearing bulky cyclopentadienyl-based ancillary ligands, CpxU (MesPDIMe)(L) (x = P (1-(7,7-dimethylbenzyl)), * (1,2,3,4,5-pentamethyl); L = THF, HMPA), have been synthesized. These species have the ability to perform one, two, and four electron reduction of a variety of substrates. For examples, uranium mediated pinacol coupling of carbonylated substrates as well as oxidative addition toward two (X2, PhE-EPh, PhE-X) and four electron (Ar-N=N-Ar’, oxygen-atom transfer reagents) organic oxidants have been studied. with both radical and concerted addition pathways operable. Synthesis of a trans-dioxo species, Cp*UO2(MesPDIMe), has allowed for the study of the activation of the robust U=O double bonds—providing key insights into the necessary components for U=O bond scission. The lessons learned from the reductive silylation of this complex redox-active ligand species has allowed for application of these principles to simple UO 22+ systems.
"],"dc:identifier":["https://docs.lib.purdue.edu/open_access_dissertations/955"],"dc:subject":["Pure sciences","Redox-active ligands","Uranium","Chemistry","Inorganic Chemistry"],"dc:title":["Redox-active ligand uranium complexes for approaches to multi-electron chemistry"],"thesis:degree_discipline":["Chemistry"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Doctor of Philosophy (PhD)"]},"updated_at":"2026-07-24T03:54:09Z"}