Electronic communication and switching between two iron atoms across the phenanthrene–dihydrophenanthrene bridging ligands

Abstract

The complexes [{Fe(η⁵-C₅Me₅)}₂(µ₂,η¹²-phenanthrene)]ⁿ⁺ have been synthesized for n= 0–2; the green 37-electron mixed-valence Fe^IFe^II monocation is delocalized on the Mössbauer time-scale at 4 K and the bireduced neutral complex has a triplet Fe^IFe^I state for phenanthrene in contrast with the singlet Fe^IIFe^II state for the dihydrophenanthrene complex; interconversion between the phenanthrene and dihydrophenanthrene series by contact with O₂and H₂O makes this system a switchable molecular-electronic device.