Ansa-metallocene complexes (III) - synthesis and application in ethylene polymerization of sila-bridged bis(indenyl and tetrahydroindenyl) titanium and zirconium complexes

Tetramethyldisilane-bridged bis(1-indenyl and tetrahydroindenyl) metallocene dichlorides(Me2SiSiMe2)Ind2MCl2[M = Ti (1), Zr (2)] and (Me2SiSiMe2)[IndH4]2MCl2[M = Ti (3), Zr(4)] were synthesized. Complexes 1-4 were characterized by 1H NMR, mass spectra and elemental analyses. Complexes 3 and 4 were used for the polymerization of ethylene after activation with methyl aluminoxane(MAO) at different temperatures and normal pressure. The titanocene 3 shows a lower activity but produces polyethylene with a higher molecular weight than zirconocene 4. The catalyst systems show a dependency of the activity and molecular weight on temperature.