Stereospecific Styrene Polymerization and Ethylene-Styrene Copolymerization with Titanocenes Containing a Pendant Amine Donor

A series of monocyclopentadienyl titanium complexes containing a pendant amine donor on a Cp group (A = CpTiCl3,. B = (CpTiCl3)-Ti-N, C = (CpTiCl2TEMPO)-Ti-N, for Cp = C5H5, Cp-N = C5H4CH2CH2N(CH3)(2), and TEMPO = 2,2,6,6-tetramethylpiperidine-N-oxyl) are investigated for styrene homopolymerization and ethyl e ne-styrene (ES) copolymerization. When activated by methylaluminoxane at 70 degrees C, complexes with the amine group (B and C) are active for styrene homopolymerization and afford syndiotactic polystyrene (sPS). The copolymerizations of ethylene and styrene with B and C yield high-molecular weight ES copolymer, whereas complex A yields mixtures of sPS and polyethylene, revealing the critical role that the pendant amine has on the polymerization behavior of the complexes. Fractionation, NMR, and DSC analyses of the ES copolymers generated from B and C suggest that they contain sPS. (C) 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48:1579-1585,2010