Unbridged metallocene dichloride complexes with mono-substituted indenyl ligands and their application for the polymerization of propene

The synthesis of unbridged metallocene dichloride complexes of the type Ind′2ZrCl2 (Ind′=2-alkyl- or arylalkyl-substituted indenyl) is described. The complexes are characterized by 1H- and 13C-NMR spectroscopy and mass spectrometry. After activation with methylalumoxane these complexes can be used for propene polymerization; they produce block copolymers consisting of alternating isotactic and atactic blocks. The polymerization results and the polymer properties are presented. The influence of the catalyst structure on the polymerization behaviour is discussed.