ELECTRONIC COMMUNICATION AND SWITCHING BETWEEN 2 IRON ATOMS ACROSS THE PHENANTHRENE-DIHYDROPHENANTHRENE BRIDGING LIGANDS

The complexes 5)-C(5)Me(5))}(2)(mu(2),eta(12)-phenanthrene)](n+) have been synthesized for n = 0-2; the green 37-electron mixed-valence (FeF eII)-Fe-I monocation is delocalized on the Mossbauer time-scale at 4 K and the bireduced neutral complex has a triplet (FeFeI)-Fe-I state fo r phenanthrene in contrast with the singlet (FeFeII)-Fe-II state for t he dihydrophenanthrene complex; interconversion between the phenanthre ne and dihydrophenanthrene series by contact with O-2 and H2O makes th is system a switchable molecular-electronic device.