Group 4 metallocene catalysts with hapto-flexible cyclopentadienyl-aryl ligand

Catalytic precursors Ti(IV) and Zr(IV) complexes bearing cyclopentadienyl a nd substituted cyclopentadienyl and substituted cyclopentadienyl anionic li gands, bonded to phenyl or substituted phenyl through an isopropylidene bri dge have been utilized in the polymerization fo propene and styrene and in ethylene-styrene copolymerization and substituted cyclopentadienyl anionic ligands, bonded to phenyl or substituted phenyl through an isopropylidene b ridge have been utilized in the polymerization of propene and styrene and i n ethylene-styrene copolymerization. In the presence of trichloro [(1,2,3,4 ,5-eta)-1-(1-methyl-1-phenylethyl)-2,4-cyclopentadien-1-yl] titanium (LTiCl 3) we have obtained either partially isotactic (chain-end type) or atactic poly-(propylene), and either atactic or syndiotactic polystyrene depending on the reaction temperature. [1-Methyl-1-naphthylethyl-2-inden-1-yl]titaniu m(IV) behaves like (LTiCl3) in styrene polymerization, while it affords met al-controlled partially isotactic poly(propylene), as well as the correspon ding zirconium compounds. The experimental data are tentatively explained b y the temperature dependence of coordination of the bridged aryl group of t he ligand.