The electrochemical synthesis of η5-cyclopentadienylcobalt-η4-tetraphenylbutadiene and its reaction with iodine in the presence of electron donor ligands

Article abstract of DOI:10.1016/S0022-328X(96)06693-4

η⁵-Cyclopentadienylcobalt-η⁴-tetraphenylbutadienes RC₅H₄CoC₄H₂Ph₄ (IIa-d: a R = H; b R = Et; c R = ⁱPr; d R = PhCH²) have been prepared by simultaneous electrolysis of a respective substituted cyclopentadiene RC₅H₅ and diphenylacetylene in acetonitrile containing up to 0.5% water, using a cobalt anode. The action of iodine on IIa-d results in the elimination of the tetraphenylbutadiene ligand and the formation of diiodides (RC₅H₄CoI₂)₂ (IIIa-d). The reaction of IIa with iodine in the presence of electron donor ligands leads to the formation of complexes CpCoI₂L, (L = Ph₃P, Py, Me₂S, dppe), [CpCoIL₂]⁺I^-₃ (L₂ = dipy, phen), (CpCoI₂)₂L (L = dppe).