Dual‐Active‐Site Nature of Magnesium Dichloride‐Supported Cyclopentadienyl Titanium Chloride Catalysts Switched by an Activator in Propylene Polymerization

MgCl₂‐supported metallocene catalysts often show peculiar catalytic aspects, which are partially similar to both non‐supported complexes and traditional Ziegler–Natta catalysts. In this study, the active‐site natures of various MgCl₂‐supported cyclopentadienyl Ti chloride catalysts are systematically investigated and compared with traditional catalysts in propylene polymerization. The supported titanocene catalysts offer both metallocene‐type and Ziegler–Natta‐type active‐site natures according to the details of the preparation and the activation procedures. The observed dual‐active‐site natures are plausibly correlated with the valence and charge states of the Ti center.