Reactivity of an Arene Cobalt Triple Decker Complex Towards Various Ligands. Facile Arene Displacement in [Bis{( η5-pentamethylcyclopentadienyl)cobalt}-μ-{η4: η4-toluene}

Abstract

The triple decker complex [{(η5-Cp*)Co}2-μ-{η4: η4-toluene}] 1b exhibits an unusual reactivity towards a variety of organic ligands, 1b reacts with CO, ethene, butadiene, H2, Al2O3, hexafluorobenzene, 1.5 Cod, 2-butyne, phenanthrene, naphthalene and the dinuclear Ni cluster [{(η5-Cp)NiP(C2H5)3}2] to form mainly mononuclear organocobalt complexes. Reaction of 1b with NO and the diazoalkanes di-t-butyl-diazomethane and 2-diazo-1,1′,3,3′-tetramethylcyclohexane results in the formation of the dinuclear complexes [{(η5-Cp*)CoNO}2], [{(η5-Cp*)(di-t-butyl-diazomethane)Co}2] and [{(η5-Cp*)(2-diazo-1,1′,3,3′-tetramethylcyclohexane) Co}2], respectively. In the reaction of 1b with elemental sulfur the formation of a tetranuclear Co-sulfide cluster is observed. In the majority of the reactions studied, l b looses its toluene ligand already at room temperature indicating an unusual high and hitherto unprecedented reactivity of an arene triple decker complex.