ONSET OF BAND-LIKE PROPERTIES IN THE LIGAND-BRIDGED, TRIMERIC CLUSTER ([(PY)2RU3O(OAC)6(PYR)]2[RU3O(OAC)6(CO)])

The ligand-bridged trimeric cluster {[(py)2Ru3O(CH3CO2)6(pyr)]2[Ru3O(CH3CO2)6(CO)]}(PF6)2 (py = pyridine, pyr = pyrazine) has been prepared by a reaction between the monomeric clusters Ru3O(CH3CO2)6(pyr)]+ and Ru3O(CH3CO2)6(CH3OH)2(CO)]. Electrochemical studies show that the trimer has an extraordinary degree of reversible electron-transfer chemistry. Its optical and redox properties are of interest when compared to those of the monomer units which make it up. When its total electron content is low, which is the case, for example, in the 2+ ion mentioned above, its properties are those expected for isolated cluster units where intercluster electronic interactions are weak. However, the results of electrochemical studies suggest that as electron content increases, electronic coupling between the cluster sites is enhanced and the appearance of a series of closely spaced, one-electron waves may signal the appearance of band-like behavior in this discrete chemical system. Copyright © 1979, American Chemical Society. All rights reserved.