ChemInform Abstract: Electrochemistry of Carbonyl(fulvalene)dimetal Complexes (M₂: Cr₂, Mo₂, W₂, Ru₂, Mo-Ru) in Aprotic Media.

ChemInform Abstract

All of the metal-metal-bonded compounds (I) behave analogously in electrochemical studies. They are oxidized and reduced in 2e processes. Cyclic voltammetric experiments show that the oxidation process is irreversible. The reduction occurs with cleavage of the metal-metal bond in an ECE or ECEC mechanism. The resulting dianions (II) are oxidized at relatively positive potentials to re-form the metal-metal bond. Scan rate and wave shape studies of the dimers (Ia) and (Ib) are carried out to investigate the heterogeneous-electrontransfer rates. Computer simulations of cyclic voltammetry data based on the ECE mechanism show that radical-anion intermediates of the homonuclear compounds disproportianate at a fast rate. The metal-metal bond of the compounds (I) is cleaved upon reaction with I2 and Br2 to give dihalide products. The electrochemistry of ′25 these products is also examined. The dichromium diiodide and diruthenium dibromide reduce in a 2e process to the metal-metal-bonded dimers, releasing 2 equiv. of halide. The dimolybdenum and diruthenium diiodides reduce to unknown products.