(.eta.5-Indenyl)trichlorotitanium. An improved syndiotactic polymerization catalyst for styrene

(η 5 -Indenyl)trichlorotitanium was synthesized in 96% yield, its X-ray structure was obtained and it was shown to exhibit unusually high activity and syndioselectivity in styrene polymerizations which are relatively insensitive to the polymerization temperature, catalyst concentration and [Al]/[Ti]