Synthesis, electrochemistry, and reactivity of cerium(III/IV) methylene-bis-phenolate complexes

Inorg Chem. 2013 May 20;52(10):5970-7. doi: 10.1021/ic400202r. Epub 2013 Apr 26.

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.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Cerium / chemistry*
  • Crystallography, X-Ray
  • Electrochemical Techniques*
  • Models, Molecular
  • Molecular Structure
  • Organometallic Compounds / chemical synthesis*
  • Organometallic Compounds / chemistry*
  • Phenol / chemistry*

Substances

  • Organometallic Compounds
  • Cerium
  • Phenol