Intermolecular coupling of the allenyl ligand on tungsten to form hexa-1,5-diene aided by triosmium clusters

Abstract

The propynyl ligand of the trimethyl phosphite substituted tungsten complex [(η⁵-C₅H₅)W(CO)₂{P(OMe)₃}(CH₂CCH)] is converted to an allenyl ligand at room temperature and the reaction of [(η⁵–C₅H₅)W(CO)₃(CHCCH₂)] with [H₂Os₃(CO)₁₀] yields the coupling product [H₂Os₆(CO)₂₀(C₆H₈)](4); the structure of (4), established by X-ray crystallography, confirms the presence of a hexa-1,5-diene ligand with two alkene groups bound to two triosmium clusters in a µ,η²-fashion.