title: Synthesis, electrochemistry, and reactivity of cerium(III/IV) methylene-bis-phenolate complexes.
abstract: A series of cerium complexes containing a 2,2'-methylenebis(6-tert-butyl-4-methylphenolate) (MBP(2-)) ligand framework is described. Electrochemical studies of the compound [Li(THF)2Ce(MBP)2(THF)2] (1) reveal that the metal based oxidation wave occurs at -0.93 V vs Fc/Fc(+). This potential demonstrates significant stabilization of the cerium(IV) ion in the MBP(2-) framework with a shift of ∼2.25 V from the typically reported value for the cerium(III/IV) couple of E°' = +1.30 V vs Fc/Fc(+) for Ce(ClO4)3 in HClO4 solutions. Compound 1 undergoes oxidation to form stable cerium(IV) species in the presence of a variety of common oxidants. The coordination of the redox-active ligands 2,2'-bipyridine and benzophenone to 1 result in complexes in which no apparent metal-to-ligand charge transfer occurs and the cerium ion remains in the +3 oxidation state.
authors.affiliation: P. Roy and Diana T. Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States.
authors.forename: Brian D
authors.initials: BD
authors.lastname: Mahoney
authors.forename: Nicholas A
authors.initials: NA
authors.lastname: Piro
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: Carroll
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Schelter
mesh_terms: D002563:Cerium / Q000737:chemistry*; D018360:Crystallography, X-Ray; D055664:Electrochemical Techniques; D008958:Models, Molecular; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis* / Q000737:chemistry*; D019800:Phenol / Q000737:chemistry*
chemical_list: D009942:Organometallic Compounds; D002563:Cerium; D019800:Phenol