Design of bifunctional organometallic ‘electron reservoirs’: 35- to 38-electron sandwiches including the first stable, localized mixed valence complexes containing FeI

Abstract

The new bimetallic complex (cpFe)(cp–cp)(FeC₆Me₆)⁺PF₆^–, (cp = C₅H₅)(2), synthesized from biferrocene and C₆Me₆, shows four oxidation states (Fe^IIIFe^II)²⁺, (Fe^IIFe^II)⁺, Fe^IIFe^I, and (Fe^IIFe⁰)^– reversibly connected by cyclic voltammetry; the first three are stable and can be isolated and Mössbauer spectroscopy was used to investigate the electronic structure of the localized mixed valence Fe^IIFe^I.