The synthesis of a series of C1-symmetric metallocene complexes rac-[1-(5,6-dialkoxy-2-methyl1-η5-indenyl)-2-(9-η5-fluorenyl)ethane]zirconium dichlorides (alkyl: n-butyl, n-hexyl, n-octyl, ndecyl) is described. These complexes are versatile catalysts in the polymerization of propylene after in situ activation with triisobutylaluminum (TIBA) and Ph3C[B(C6F5)4] in toluene and heptane solution. Al...

A commercial SiO2 modified by the addition of a TiO2 layer on its surface and pore walls offers support for metallocene-based ethylene polymerization catalysts with 35% improved catalytic activity. The effect such modification catalyst particle fragmentation during reactions were assessed. This was performed exposing internal cross-section several Ti/SiO2-based metallocene particles, polymerize...

Bis(2-R-ind)ZrCl2 (R: H or phenyl) was supported on different types of silica by in situ impregnation method and used for ethylene polymerization. In this method, the step of catalyst loading on support was eliminated and common alkyl aluminum (triisobutylaluminum, TiBA) cocatalyst was used instead of expensive methyl aluminiumoxane (MAO) cocatalyst in the polymerization. The effect of surface ...

bis(2-r-ind)zrcl2 (r: h or phenyl) was supported on different types of silica by in situ impregnation method and used for ethylene polymerization. in this method, the step of catalyst loading on support was eliminated and common alkyl aluminum (triisobutylaluminum, tiba) cocatalyst was used instead of expensive methyl aluminiumoxane (mao) cocatalyst in the polymerization. the effect of surface ...

Both metallocene and Phillips chromium catalysts are used in the commercial manufacture of polyethylene. Unlike most other systems, Chevron Chemical (CPC) platform does not use methylaluminoxane or fluoroorganic boranes. Instead, support itself serves to activate (ionize) metallocenes, which then polymerize ethylene at high activity. Most these solid acid supports can also be anchor Cr make a c...

In this study we have tested the ability of a standard DFT computational protocol to reproduce the experimentally obtained stereoselectivity of 26 different C2-symmetric zirconocene catalysts active in propylene polymerization. The catalysts were chosen for their relevance in metallocene catalyzed polymerization of propylene. To this end, primary insertion of both si- and re-propylene enantiofa...