Author/Authors :
Ana M. Martins، نويسنده , , M. Mercês Marques، نويسنده , , José R. Ascenso، نويسنده , , Alberto R. Dias، نويسنده , , M. Teresa Duarte، نويسنده , , Anabela C. Fernandes، نويسنده , , Susete Fernandes، نويسنده , , M. Jo?o Ferreira، نويسنده , , Ines Matos، نويسنده , , M. Conceiç?o Oliveira، نويسنده , , Sandra S. Rodrigues، نويسنده , , Marie-Claire Wilson، نويسنده ,
Abstract :
The syntheses of ketimide titanium complexes of the type Ti(Ndouble bond; length as m-dashCtBu2)3X (X = Cl, Cp, Ind), Ti(Ndouble bond; length as m-dashCtBu2)4 and the zirconium complex CpZr(Ndouble bond; length as m-dashCtBu2)2Cl are described. When activated by MAO, all compounds are ethylene polymerisation catalysts. In the conditions studied, the most active catalyst is CpZr(Ndouble bond; length as m-dashCtBu2)2Cl, with an activity of 2.7 × 105 kg/(molZr [E] h). Titanium complexes are less active by about two orders of magnitude. The polyethylene produced is linear, as determined by NMR spectroscopy. Molecular structures of Ti(Ndouble bond; length as m-dashCtBu2)3X (X = Cl, Cp, Ind) and Ti(Ndouble bond; length as m-dashCtBu2)4 were determined by X-ray single crystal diffraction.
Keywords :
Titanium , Zirconium , Ketimide complexes , Ethylene polymerisation
