| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1324150 | Journal of Organometallic Chemistry | 2005 | 11 Pages |
ZusammenfassungDie Synthese von symmetrischen, alkylidenverbrückten Zirconocenzweikernkomplexen wird beschrieben. Der Einfluss von Strukturparametern und unterschiedlicher Cokatalysatoren (MAO, Triphenylcarbeniumtetrakis(pentafluorophenyl)borat oder Tris(pentafluorophenyl)boran) auf die homogene Propylenpolymerisation wird untersucht. Die dinuklearen Katalysatoren zeigen bei Aktivierung mit MAO die höchsten Aktivitäten, mit Triphenylcarbeniumtetrakis(pentafluorophenyl)borat den höchsten Grad an Isotaktizität. Gegenüber einem einkernigen Referenzkatalysator erzielte der mit MAO aktivierte dinukleare Komplex eine höhere Propylenpolymerisationsaktivität und das erhaltene Polymer weist eine höhere Molmasse als das des Einkernkomplexes auf.
The synthesis is described of symmetric alkylidene bridged dinuclear zirconocene complexes. The influence of structural parameters and different cocatalysts such as methylaluminoxane (MAO), triphenyl tetrakis(pentafluorophenyl)borate- or tris(pentafluorophenyl)borane has been investigated for homogeneous propylene polymerization. The dinuclear catalysts show highest polymerization activities by activation with MAO. Activation with triphenyl tetrakis(pentafluorophenyl)borate results in polypropylenes with the highest degree of isotacticity. Compared to the mononuclear reference catalyst the dinuclear MAO activated complex achieved higher propylene polymerization activity and the polypropylene obtained from the dinuclear complex has a higher molecular weight than that one that was produced with the mononuclear complex.
Graphical abstractThe synthesis and characterization of various symmetric dinuclear metallocene complexes is described. After activation with different cocatalysts, such as methylalumoxane (MAO), [CPh3]+ [B(C6F5)4 ]− or B(C6F5)3, the resulting catalysts are used for the homogeneous polymerization of propylene. The performance of the various catalysts and the extent of stereoselectivity of the polymerization is dependent on the nature of the corresponding cocatalyst.Figure optionsDownload full-size imageDownload as PowerPoint slide
