Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1321879 | Journal of Organometallic Chemistry | 2013 | 7 Pages |
A series of 2-(1-{2,6-bis[bis(4-fluorophenyl)methyl]-4-methylphenyl-imino}ethyl)-6-[1-(arylimino)ethyl]pyridylcobalt(II) chloride complexes (Co1–Co5) was synthesized and characterized by FT-IR spectroscopy and elemental analysis. The molecular structures of the representative cobalt complexes Co1 (R1 = Me, R2 = H), Co4 (R1 = Me, R2 = Me) and Co5 (R1 = Et, R2 = Me) were determined by single crystal X-ray diffraction, and revealed a pseudo-square-pyramidal geometry at cobalt. Upon activation with either MMAO or MAO, all cobalt complex pre-catalysts exhibited high activities [up to the range of 107 g of PE (mol of Co)−1 h−1] toward ethylene polymerization. The influence of reaction parameters and the nature of the ligands were investigated in detail on the catalytic activities of the corresponding complexes and properties of the resultant polyethylene. The cobalt system revealed single-site behavior and produced polyethylene with narrow molecular distribution. Compared to the use of MAO, the use of MMAO produced polyethylene of higher molecular weight.
Graphical abstractThe 2-(1-{2,6-bis[bis(4-fluorophenyl)methyl]-4-methylphenylimino}ethyl)-6-[1-(arylimino)ethyl]pyridylcobalt(II) chloride complexes (Co1–Co5) were synthesized and fully characterized. Upon activation with either MMAO or MAO, all cobalt complex pre-catalysts exhibited high activities [up to the range of 107 g of PE (mol of Co)−1 h−1] toward ethylene polymerization.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Newly synthesized 2-(1-{2,6-bis[bis(4-fluorophenyl)methyl]-4-methylphenylimino}ethyl)-6-[1-(arylimino)ethyl]pyridines. ► Synthesis and characterization of new cobalt complexes. ► Highly active cobalt pre-catalysts in ethylene polymerization. ► Polyethylene with narrow polydispersity.