Synthesis and catalytic activity in ethylene polymerization of yclopentadienylterbium dibromides with pyrazole or triphenylphosphine ligand

摘要

Organoterbium compounds TbBr_2CpHPz and TbBr_2CpPPh_3 were obtained by reaction of pyrazole or triphenylphosphine ligands with cyclopentadienylterbium dibromide. These compounds were characterized by elemental analysis, complexometric titration with EDTA, thermal analysis, vibrational spectra in the infrared region and ~1H NMR. In a preliminary catalytic study, these compounds were active in ethylene polymeriation when MAO was used as cocatalyst, producing low crystalline polyethylene.