UC Santa Barbara

Addition of PR3 (R=Ph or OPh) to [Cu(η(2)-Me6C6)2][PF6] results in the formation of [(η(6)-Me6C6)Cu(PR3)][PF6], the first copper-arene complexes to feature an unsupported η(6) arene interaction. A DFT analysis reveals that the preference for the η(6) binding mode is enforced by the steric clash between the methyl groups of the arene ligand and the phenyl rings of the phosphine co-ligand.