SYNTHESIS AND POLYMERIZATION BEHAVIOR OF VARIOUS SUBSTITUTED INDENYL TITANIUM COMPLEXES AS CATALYSTS FOR SYNDIOTACTIC POLYSTYRENE

Five substituted indenyltrichlorotitanium compounds have been synthesi zed and characterized by spectroscopic methods and their catalytic beh avior for the polymerization of styrene was studied in the presence of methylaluminoxane (MAO) as a cocatalyst. Substituted indenyl ligands include 1,3-dimethyl, 1-methyl, 1-ethyl, 1-isopropyl and 1-(trimethyls ilyl)indenyl groups. All five compounds gave extremely pure syndiotact ic polystyrene, with conversion rates of at least 95%, and their catal ytic properties were compared with the data obtained from the (eta(5)- indenyl)trichlorotitanium-MAO system. The catalytic activity is enhanc ed by less bulky and better electron-releasing substituents of the ind enyl ligand.