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 kgPE/(molTi 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 (Mw/Mn from 1.6 to 2.2).

Graphical abstractSynthesis of new titanium dichloro complexes bearing modifiable pyrazolonato- and pyrazolonato-ketimine ligands is described. After MAO activation complexes were used in ethylene polymerization and it was found that both activity and the produced polymer were highly depended on the ligand framework.Figure optionsDownload full-size imageDownload as PowerPoint slide