Titanium complexes with modifiable pyrazolonato and pyrazolonato-ketimine ligands: Synthesis, characterization and ethylene polymerization behavior

Six titanium complexes bearing pyrazolonato and pyrazolonato-ketimine ligands have been synthesized and characterized. It was found that the ligand structure of the synthesized complexes has a significant effect on the catalytic performance of the complexes. The synthesized complexes were activated with MAO and their activities varied from negligible to high (up to 612 kg_PE/(mol_Ti h bar). The pyrazolonato-ketimine complex with a phenyl substituent in the imine part was the most active in the series and it was the only one producing polyethylenes with relatively narrow molecular weight distribution (M_w/M_n from 1.6 to 2.2).