DFT studies of the methyl exchange reaction between Cp2M–CH3or Cp*2M–CH3(Cp = C5H5, Cp* = C5Me5, M = Y, Sc, Ln) and CH4. Does M ionic radius control the reaction?

DFT studies of the methyl exchange reaction between Cp2M–CH3or Cp*2M–CH3(Cp = C5H5, Cp* = C5Me5, M = Y, Sc, Ln) and CH4. Does M ionic radius control the reaction?