Immobilization of CrCl3(THF)(3) on a cyclopentadienyl surface of silica

Heterogeneous cyclopentadienylchromium catalysts were synthesized by adsorb ing chromiumtrichloride CrCl3(THF)(3) on a cyclopentadienyl modified silica surface. The obtained catalysts and the homogeneous model compound, [CpCrM e(mu-Cl)](2) (Cp = eta(5)-C5H5), were tested in the polymerization of ethyl ene with the presence of the methylaluminoxane (MAO) cocatalyst. The hetero geneous catalyst showed a good activity toward ethylene but the main produc ts were oligomers, mainly n-butene. The homogeneous catalyst was a better p olymerization catalyst but it also produced oligomers. Heterogeneous cataly sts were characterized with FTIR and C-13 and Si-29 CP MAS NMR. (C) 2000 El sevier Science B.V. All rights reserved.