Ethylene Polymerization Catalyzed by Pyrene-Tagged Iron Complexes: The Positive Effect of p-Conjugation and Immobilization on Multiwalled Carbon Nanotubes

摘要

2-[1-(2,6-Diisopropylphenylimino)ethyl]-6-[1-(pyren-1-ylimino)ethyl]pyridine (L1) and 2,6-bis[1-(pyren-1-ylimino)ethyl]pyridine (L2) were synthesized and used to prepare the corresponding Fe complexes Fe1 and Fe2 from FeCl2. All new compounds were characterized, and single-crystal XRD analysis of Fe1 was performed. The -conjugated pyrenyl substituent enhanced the catalytic activity of the Fe complexes, which display high activity in ethylene polymerization up to 10(7)g(PE)mol(Fe)(-1)h(-1) (PE=polyethylene). These Fe complexes were easily immobilized on multiwalled carbon nanotubes (MWCNTs) through noncovalent - interactions. The supported precatalysts showed better ethylene polymerization activity than their homogeneous counterparts to produce well-dispersed MWCNT/PE composite materials.