Half-Sandwich Titanium Complexes Stabilized by a Novel Silsesquioxane Ligand:  Soluble Model Systems for Silica-Grafted Olefin Polymerization Catalysts

The cuboctameric silsesquioxane silanol ( c -C 5 H 9 ) 7 Si 8 O 12 (OH) has been applied as a model support for silica-grafted olefin polymerization catalysts. Complexes of the type Cp‘‘[( c -C 5 H 9 ) 7 Si 8 O 13 ]TiX 2 (Cp‘‘ = 1,3-C 5 H 3 (SiMe 3 ) 2; X = Cl, CH 2 Ph) form active α-olefin polymerization catalysts.