Functional organometallic electron reservoirs: the 19-electron complexes (η5-C5H4CO2H)(η6-C6Me6)FeI and (η5-C5H4CO2–)(η6-C6Me6)FeI

Abstract

Na–Hg reduction of [(η⁵-C₅H₄CO₂H)(η⁶-C₆Me₆)Fe^II]⁺PF₆^–, (1), rapidly gives the blue, thermally labile, air-sensitive acid (η⁵-C₅H₄CO₂H)(η⁶-C₆Me₆)Fe^I, (3), and (more slowly) the purple thermally stable, extremely reactive, radical anion (η⁵-C₅H₄CO₂^–)(η⁶-C₆Me₆)Fe^I, (4), which is also obtained directly by Na–Hg reduction of the zwritterion (η⁵-C₅H₄CO₂^–)(η⁶-C₆Me₆)Fe⁺PF₆^–, (2); spontaneous oxido-reduction of (3) and reaction of (3) or (4) with O₂ gives (2).