Immobilization of CrCl 3(THF) 3 on a cyclopentadienyl surface of silica

Abstract

Heterogeneous cyclopentadienylchromium catalysts were synthesized by adsorbing chromiumtrichloride CrCl 3(THF) 3 on a cyclopentadienyl modified silica surface. The obtained catalysts and the homogeneous model compound, [CpCrMe(μ-Cl)] 2 (Cp=η 5-C 5H 5), were tested in the polymerization of ethylene with the presence of the methylaluminoxane (MAO) cocatalyst. The heterogeneous catalyst showed a good activity toward ethylene but the main products were oligomers, mainly n-butene. The homogeneous catalyst was a better polymerization catalyst but it also produced oligomers. Heterogeneous catalysts were characterized with FTIR and 13C and 29Si CP MAS NMR.