| 초록 |
A new α-diimine ligand, 9-(2, 6-dimethylphenylimino)-10-(2, 1’-methylene-6-methyl phenylimino)-9, 10-dihydrophenanthrene was prepared by dehydrating condensation of phenanthrenequinone with 2, 6-dimethylaniline catalyzed by TiCl4/Dabco system. Reaction temperature was a crucial factor on yields of this single-sided alkylation coupled ligand. A series of catalysts were obtained by selective imine hydrolysis of the non-coupled part and the following reactions with other anilines. The coordination reactions of these ligands with (DME)NiBr2 produced the (α-diimine)nickel catalysts that were found to catalyze ethylene polymerization with comparable activities to typical Brookhart’s α-diimine nickel catalysts in the presence of MAO. It was observed that the steric and eleronic structure of catalysts and reaction conditions had significant influences on polymerization activities, molecular weights and microstructures of the polyethylenes. |
