SYNTHESIS AND ELECTROCHEMICAL AND EPR STUDIES OF SPIKED BUTTERFLY METAL-CLUSTERS CONTAINING AN FE(3)HGM CORE (M=MO, W, FE, MN, CO)

The reaction of the PPh(4)(+) salt of [Fe-3(CO)(11)](2-) with ClHg(m) complexes (m = metal fragment) in tetrahydrofuran gives high yields of the new pentametallic clusters (PPh(4))[Fe-3(Co)(10)(mu-Co)(mu-Hg(m)) ] (m = Mo(CO)(3)Cp (1), W(CO)(3)Cp (2), Fe(CO)(2)Cp (3), Mn-(CO)(5) (4 ), Co(CO)(4) (5)) showing a spiked butterfly geometry, according to th eir IR, FAB, and Mossbauer spectra. These species are stable toward me tal ligand redistribution processes. The electrochemical oxidation of these mixed transition metal-mercury clusters led to the paramagnetic species [Fe-3(CO)(11)(mu-Hgm)](.), which have been identified by EPR s pectroscopy. From those parameters it is deduced that the unpaired ele ctron is mainly localized in the Fe3Hg butterfly metallic core.