General. All manipulations were performed in an inert argon atmosphere with rigorous exclusion of oxygen and water using Schlenk line and glovebox techniques. The solvents n-hexane, toluene and benzene were dried by refluxing over potassium and stored over potassium mirrors. Pentane was dried by refluxing over NaK and stored over a potassium mirror. Fluorobenzene and orthodifluorobenzene were dried by refluxing over CaH2 and was stored over 4 Å molecular sieves.