Heterogeneous Constrained-Geometry Zirconium Catalysts

Autor: Hannele Juvaste and, Tuula T. Pakkanen, Eero Iiskola
Rok vydání: 2000
Předmět:
Zdroj: Organometallics. 19:1729-1733
ISSN: 1520-6041
0276-7333
Popis: Heterogeneous constrained-geometry catalysts were prepared by immobilizing Zr(NMe2)4 on a heterogenized ansa-cyclopentadienylamino ligand of type (RN)R‘R‘ ‘Si(C5R‘ ‘‘4): surface 1, R = −O-Me2Si(CH2)3; R‘, R‘ ‘, R‘ ‘‘ = Me; surface 2, R = −O-Me2Si(CH2)3; R‘, R‘ ‘‘ = Me, R‘ ‘= H. The preparation of the constrained-geometry catalyst ligand on a silica surface has been carried out in two steps: first, functionalizing the silica surface with aminopropyldimethylethoxysilane (APDMES) by using saturated gas−solid reactions, and then immobilizing two different (tetramethylcyclopentadienyl)chlorosilanes, Me2Si(C5Me4H)Cl and MeHSi(C5Me4H)Cl, on the APDMES-functionalized silica by utilizing n-BuLi (n-butyllithium). Zr(NMe2)4 was immobilized on the heterogeneous surfaces using the amine elimination reaction. The two heterogeneous monocyclopentadienylamido zirconium catalysts were characterized with 1H, 13C, and 29Si solid-state NMR and FTIR spectroscopy and tested for ethylene polymerization.
Databáze: OpenAIRE