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

Tetramethyldisilane-bridged bis(l-indenyl and tetrahydroindenyl) metallocen e dichlorides (Me2SiSiMe2) Ind(2)MCl(2) [M = Ti (1), Zr (2)] and (Me2SiSiMe 2) [IndH(4)](2)MCl2[M = Ti (3), Zr(4)] were -synthesized, Complexes 1-4 wer e characterized by H-1 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 dependenc y of the activity and molecular weight on temperature.