Ligand Exchange and Alkyl Abstraction Involving (Perfluoroaryl)boranes and -alanes with Aluminum and Gallium Alkyls

Reaction between M(C6F5)3 (M = B, Al) and AlR3 in hydrocarbons leads to facile aryl/alkyl group exchange and formation of aluminum dimers, while reaction of (perfluoroaryl)boranes B(C6F5)3 and B(C12F9)3 with AlR3 (R = Me, Et, octyl) or GaMe3 in ether solvents produces alumocenium or gallocenium borates. Neutral aluminum dimers and cationic alumocenium species have been found to be very effective as catalyst activators in ethylene/1-octene copolymerization.