Synthesis of 3,3,3-Trifluoropropyl Substituted Cyclopentadienes and Their Zirconocene Derivatives: Catalytic Applications in the Polymerization of Ethylene

The synthesis and structure of novel 3,3,3-trifluoropropyl substituted cyclopentadienes (2/3) and of their zirconocene dichloride derivatives [Zr(η5-C5H4C2H4CF3)2Cl2] (6) and [Zr{η5-C5H3-1,2-(C2H4CF3)2}2Cl2] (7) is reported. These precatalysts have been investigated toward their properties in the methylaluminoxane (MAO) assisted polymerization of ethylene. The results can be compared to the polymerization properties of the non-fluorinated analogue [Zr(η5-C5H4C2H4CH3)2Cl2] (11). Complexes 6 and 7 produce high-density polyethylene (HDPE) and are among the most active precatalysts for donor functionalized nonbridged metallocenes. An unprecedented temperature independence of the molar mass distribution is observed for the polymerization with 6.