High-molecular-weight atactic polypropylene from metallocene catalysts .1. Me(2)Si(9-flu)(2)ZrX(2) (X=Cl, Me)

The synthesis and characterization of the C-2v symmetric (dimethylsilanediylbis(9-fluorenyl))zirconium dichloride (I) and (dimethylsilanediylbis(9-fluorenyl))zirconium dimethyl (II) are reported. The crystal and molecular structure of II has been solved. The catalyst system I/MAO and II/MAO (MAO = methylalumoxane) produce high-molecular-weight atactic polypropylene at relatively high polymerization temperatures (<(M)over bar (w)> = (1-4) x 10(5) at 50 degrees C and Al/Zr = 1200) in good yields, providing a practical entry to this novel, elastomeric propylene homopolymer.