Alkyl abstraction from {Me(3)SiN(CH(2)CH(2)NSiMe(3))(2)}ZrR(2) (N(3)ZrR(2); R = CH(2)Ph, Me) using B(C6F5)(3) affords cationic alkyl complexes stabilized by a diamide ligand. The ionic eta(2)-benzyl adduct decomposes slowly to give a cationic cyclometalation product, which coordinates the [PhCH(2)B(C6F5)(3)](-) anioin; the methyl cation coordinates the anion [MeB(C6F5)(3)](-) via a Zr...Me-B interaction. The complexes exhibit moderate ethene polymerization activity.