eta 6-Arene complexes of Ni(II), efficient catalysts for 1,3-butadiene and styrene polymerization.

A simple procedure for the preparation of cationic arene complexes of Ni(II) of composition [Ni(eta 6-ArX)(eta 3-C3H5)]+[BAr'4]- (X = OH, H) is reported. These compounds are shown to behave as highly active catalysts for the polymerization of 1,3-butadiene and styrene.