Isolation and Crystal Structure of [(*-OEt)(py)CoCo(CO)4]2, a Dimeric Alkoxycobalt Cobalt Tetracarbonyl, and of Its Product of Reaction with CO2, [(OC)4CoCo(py)(*-O2COEt)(*-OEt)(py)CoCo(CO)4]

The synthesis and complete characterization of an alkoxycobalt cobalt tetracarbonyl is reported. In pyridine, the cobalt-cobalt bond of the complex undergoes heterolytic splitting. In hydrocarbons or THF, under high CO pressures the complex is converted into dicobalt octacarbonyl and (ethoxycarbonyl)-cobalt tetracarbonyl. In cyclohexane, CO2 reacts reversibly with the complex, a product showing a Co-O-Co-O-C-O six-membered ring being isolated and structurally characterized.