New half-sandwich metallocene catalysts for polyethylene and polystyrene

A new type of half-sandwich metallocene catalysts for the polymerization of ethylene and styrene, Cp*MCl(DEA-R) (DEA = (OCH2CH2)(2)N, R = Me, M = Ti ( 1); R = Me M = Zr (2); R = n-Bu, M = Ti (3)), was prepared by the reaction of corresponding N-alkyl-N,N-diethanolamine with Cp*MCl3 in the presence of triethylamine. Compounds 1-3 are slightly air-sensitive and thermally unst able. All catalyst systems show moderate activities in ethylene polymerizat ion and especially the 2/MMAO system gives PE with broad molecular weight d istribution at all polymerization temperatures. In addition, 1/MMAO and 3/M MAO show fairly good activities in sPS polymerization in the order 3/MMAO > 1/MMAO. (C) 2001 Elsevier Science B.V. All rights reserved.