ELECTROCHEMICAL BEHAVIOR AND CHEMICAL OXIDATION STUDY OF THIO-BRIDGED AND PHOSPHIDO-BRIDGED BINUCLEAR IRON COMPLEXES

The electrochemical behaviour of thio and phosphido complexes of iron(I): Fe2XY(CO)6nLn (X = Y = SR, PR2 and X = SR, Y = PR2, L = PR3) has been studied on platinum and mercury electrodes, in organic solvent. These complexes are reduced in a two-electron irreversible process. A large difference is observed between their oxidation potentials on mercury and platinum electrodes; this is ascribed to the formation of a mercury complex in which mercury is inserted into the metalmetal bond. In oxidation on platinum electrodes, two mono-electronic waves are observed. The influece of the ligand basicity on the cathodic E 1 2 values is discussed. A parallel shift is observed between the E 1 2 and the IR ν(CO) of the totally symmetrical mode. Chemical oxidation of the complexes shows that the dications cannot be isolated, and leads to isolation of the following species: [FeP(CH3)2(CO)3]2AgNO3, [FeSCH3(CO)2P(CH3)3]2(NO3)2, {[FeSCH3(CO)2P(CH3)3]2F} PF6, where NO3- and F- act as ligands. © 1979.