Titanium Complexes of Chelating Bis(phenolato) Ligands with Long Titanium−Sulfur Bonds. A Novel Type of Ancillary Ligand for Olefin Polymerization Catalysts

The sulfide-linked bis(phenol) tbmpH 2 (tbmp = 2,2‘-thiobis(6- tert -butyl-4-methylphenolato)) gives a series of titanium complexes of the formula [Ti(tbmp)X 2 ] 2 or [Ti(tbmp)(L)X 2 ] (L = two-electron ligand, X = one-electron ligand). The molecular structures of [Ti(tbmp)(O i Pr) 2 ] 2 and of [Ti(tbmp){C 6 H 4 (CH 2 NMe 2 )-2}Cl] were determined by single-crystal X-ray structural analyses. An unusually long titanium−sulfur bond of ∼270 pm is observed in both complexes which contain a six-coordinate titanium center. Variable-temperature NMR spectroscopy shows a fluxional coordination of the chelating aryl group in [Ti(tbmp){C 6 H 4 (CH 2 NMe 2 )-2}Cl].