A set of indenyl titanium complexes, ($η^5-1,3-dimethylindenyl$) trichlorotitanium(1), ($η^5-1-methylindenyl$)trichlorotitanium(2), ($η^5-1 -ethylindenyl$)trichlorotitanium(3), ($η^5-1-isopropylindenyl$) trichlorotitanium(4),($η^5-(1-trimethylsilyl)indenyl$)trichlorotitanium(5) was prepared and characterized by $^1H$ and $^{13}C$ FT-NMR, mass spectrometry and elementary analysis. Their catalytic behavior for the polymerization of styrene has been studied in the presence of methylaluminoxane as a cocatalyst. All five compounds show high catalytic activity ($6.9\times10^4$ - $5.4\times10^6$) and syndiotacticity (91.3 - 96.4%). Particularly, the compound 1 turns out to be most effective in terms of catalytic activity ($0.18\times10^6$ - $5.4\times10^6$) and syndiotacticity (94.3 - 96.4%) and weight average molecular weight (about $2.5\times10^5$) of the resulting polymer.
