title: Double Reduction of 4,4'-Bipyridine and Reductive Coupling of Pyridine by Two Thorium(III) Single-Electron Transfers.
abstract: The redox chemistry of uranium is burgeoning and uranium(III) complexes have been shown to promote many interesting synthetic transformations. However, their utility is limited by their reduction potentials, which are smaller than many non-traditional lanthanide(II) complexes. Thorium(III) has a greater redox potential so it should present unprecedented opportunities for actinide reactivity but as with uranium(II) and thorium(II) chemistry, these have not yet been fully realized. Herein we present reactivity studies of two equivalents of [Th(Cp'')3] (1, Cp''={C5H3(SiMe3)2-1,3}) with 4,4'-bipyridine or two equivalents of pyridine to give [{Th(Cp'')3}2{μ-(NC5H4)2}] (2) and [{Th(Cp'')3}2{μ-(NC5H5)2}] (3), respectively. As relatively large reduction potentials are required to effect these transformations we have shown that thorium(III) can promote reactions that uranium(III) cannot, opening up promising new reductive chemistry for the actinides.
authors.affiliation: School of Chemistry, The University of Manchester, Manchester, M13 9PL, UK.
authors.forename: Alasdair
authors.initials: A
authors.lastname: Formanuik
authors.affiliation: School of Chemistry, The University of Manchester, Manchester, M13 9PL, UK.
authors.forename: Fabrizio
authors.identifier: http://orcid.org/0000-0002-1743-8338
authors.initials: F
authors.lastname: Ortu
authors.affiliation: School of Chemistry, The University of Manchester, Manchester, M13 9PL, UK.
authors.forename: Jingjing
authors.initials: J
authors.lastname: Liu
authors.affiliation: School of Chemistry, The University of Manchester, Manchester, M13 9PL, UK.
authors.forename: Lydia E
authors.initials: LE
authors.lastname: Nodaraki
authors.affiliation: School of Chemistry, The University of Manchester, Manchester, M13 9PL, UK.
authors.forename: Floriana
authors.identifier: http://orcid.org/0000-0002-5541-1750
authors.initials: F
authors.lastname: Tuna
authors.affiliation: Department of Chemistry, Lancaster University, Lancaster, LA1 4YB, UK.
authors.forename: Andrew
authors.identifier: http://orcid.org/0000-0002-2876-1202
authors.initials: A
authors.lastname: Kerridge
authors.affiliation: School of Chemistry, The University of Manchester, Manchester, M13 9PL, UK.
authors.forename: David P
authors.identifier: http://orcid.org/0000-0003-1575-7754
authors.initials: DP
authors.lastname: Mills
keywords: N ligands; electron transfer; reduction; subvalent compounds; thorium