Carbon−Fluorine Bond Cleavage by Zirconium Metal Hydride Complexes

The zirconium hydride dimer [Cp2ZrH2]2 reacts with C6F6 at ambient temperature to give Cp2Zr(C6F5)F as the major product along with Cp2ZrF2, C6F5H and H2. Neither the reaction rate nor the product ratio is affected by changes in H2 pressure or the concentration of C6F6. The reaction follows zero-order kinetics. The new compound Cp2Zr(C6F5)F has been structurally characterized. [Cp2ZrH2]2 reacts with C6F5H to give Cp2Zr(p-C6F4H)F, Cp2ZrF2, C6F4H2, and H2. The zirconium hydride Cp3ZrH has been structurally characterized and also reacts with C6F6. The products of the reaction are CpH, Cp2Zr(C6F5)F, C6F5H, Cp2ZrF2, Cp4Zr, and Cp3ZrF. The reaction rate is first order in [Cp3ZrH] and [C6F6], but the product ratio is unaffected by the concentration of C6F6. Possible mechanisms of these reactions are discussed.