Reactivity of an Arene Cobalt Triple Decker Complex Towards Various Ligands. Facile Arene Displacement in [Bis{(i7 5-pentamethylcyclopentadienyl)cobalt}- fi-{rj4: i/4-toluene}]

Triple Decker Complex of Co, Arene Displacement, r/4: >/4-Toluene Ligand The triple decker complex [{(?/5-Cp*)Co}2-,M-{>74: 774-toluene}] lb exhibits an unusual reac­ tivity towards a variety of organic ligands, lb reacts with CO, ethene, butadiene, H2, A120 3, hexafluorobenzene, 1.5 Cod, 2-butyne, phenanthrene, naphthalene and the dinuclear Ni clus­ ter [{(775-Cp)NiP(C2H5)3}2] to form mainly mononuclear organocobalt complexes. Reaction of lb with NO and the diazoalkanes di-r-butyl-diazomethane and 2-diazo-l,l',3,3'-tetramethylcyclohexane results in the formation of the dinuclear complexes [{(?/5-Cp*)CoNO}2], [{(?75-Cp*)(di-/-butyl-diazomethane)Co}2] and [{(//5-Cp*)(2-diazo-l,l',3,3'-tetramethylcyclohexane)Co}2], respectively. In the reaction of lb with elemental sulfur the formation of a tetranuclear Co-sulfide cluster is observed. In the majority of the reactions studied, lb looses its toluene ligand already at room temperature indicating an unusual high and hitherto unprecedented reactivity of an arene triple decker complex.