Molecular Wire Consisting of a C₈ Chain of Elemental Carbon Bridging Two Metal Centers: Synthesis and Characterization of [{Fe(η⁵-C₅Me₅)(dppe)}₂(μ-C₈)]

Abstract

The diiron complex [{Fe(η5-C5Me5)(dppe)}2(μ-C8)] (5; dppe = 1,2-bis(diphenylphosphino)ethane) is synthesized by the oxidative coupling of Fe(η5-C5Me5)(dppe)(C⋮CC⋮CH) (4), and it is established from the properties of the thermally stable mixed-valence complex [FeII−C8-FeIII][PF6] (6) that the C8 chain acts as a molecular wire between the two metal centers, giving rise to the strongest electronic coupling through nine bonds known to date.