Polymerization of propylene by nonbridged zirconocene complexes

Article abstract of DOI:10.1246/cl.1998.571

Nonbridged zirconocene dichlorides, (1,2-Me₂-4-RC₅H₂)₂ ZrCl₂ (R = Me (3), Ph (4), p-FC₆H₄ (5), 2-furyl (6), 2-thienyl (7), and Fc (8)), and meso- and rac-(1-Me-3-PhC₅H₃)₂ZrCl₂ (9 and 10), in the presence of MAO show a high catalytic activity (8.1-17.4 × 10₆ gPP/molZr · h) in the polymerization of propylene and produce almost an atactic elastomeric polymer of high molecular weight (M_w = 10.5 - 23.2 × 10⁴). In contrast, rac-(1-Me-3-t-BuC₅H₃)₂ZrCl₂ (12) shows very low activity and produces a rather high isotactic polymer of low molecular weight.