Gel Permeation Chromatography as a Combinatorial Screening Method:  Identification of Highly Active Heteroligated Phenoxyimine Polymerization Catalysts

A number of mixed-ligand bis(phenoxyimine) titanium catalysts were screened using a pooled combinatorial approach. Gel permeation chromatography (GPC) was used to analyze polypropylene mixtures, leading to the identification of highly active catalysts. Complexes with only one ortho-fluorinated ligand are significantly more active than homoligated complexes for the syndiospecific polymerization of propylene.