Titanium Complexes Stabilized by a Sulfur‐Bridged Chelating Bis(aryloxo) Ligand as Active Catalysts for Olefin Polymerization

The mixed‐ligand complexes [Ti 2 (μ‐OR) 2 (OR) 2 (κ 3 ‐tbop) 2 ] ( 1a ) for R = Me and ( 1b ) R = Et were prepared by the reaction of Ti(OR) 4 and H 2 tbop {H 2 tbop = 2,2′‐thiobis[4‐(1,1,3,3‐tetramethylbutyl)phenol]} in methanol. Treatment of 1a and 1b with AlMe 3 led to the substitution of terminal alkoxy groups to create the organometallic compounds [Ti 2 (μ‐OR) 2 (κ 3 ‐tbop) 2 (Me) 2 ] ( 2a ) for R = Me and ( 2b ) for R = Et. Controlled hydrolysis of 2b causes the evolution of methane and the formation of the titanoxane compounds [{Ti 2 (μ‐OEt) 2 (κ 3 ‐tbop) 2 } 2 (μ‐O) 2 ]·2CH 2 Cl 2 ( 3 ). Structures of 1a , 1b , 2a , 2b , and 3 were confirmed by NMR spectroscopy; 1b and 3 were further investigated with X‐ray crystallography. Compounds 1a , 1b , 2a , and 2b were supported on MgCl 2 and when activated with aluminum alkyls, found to effectively polymerize ethylene. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)