Ethylene polymerizations with novel tantalum(V) aminopyridinato complex/MAO systems

The use of two kinds of tantalum(V) aminopyridinato complexes, bis(2-benzylaminopyridinato)trichlorotantalum(V) and trichlorobis[2,6-di(phenylamino)pyridinato-N,N′]-tantalum(V), activated by methylaluminoxane was studied in polymerization of ethylene. The activities of these homogeneous catalyst systems are comparable to those of metallocenes. The weight-average molecular weights (M̄_w) of the produced polyethylenes are between 60 000 and 200 000 and M̄_w/M̄_n ≈ 2.