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)2N, 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 unstable. All catalyst systems show moderate activities in ethylene polymerization and especially the 2/MMAO system gives PE with broad molecular weight distribution at all polymerization temperatures. In addition, 1/MMAO and 3/MMAO show fairly good activities in sPS polymerization in the order 3/MMAO>1/MMAO.