| In this dissertation, 2-chloro-cyclopentapyridin-7-one was used as the starting material, first reacted with methyl iodide, then the Stille coupling to afford 2-acetyl-6,6-dimethyl-cyclopentapyridin-7-one. When the resulting diketone compound reacted with the corresponding anilines, the desired diimine ligands were synthesized. Following that, 2-(1-(arylimino)ethyl)-7-arylimino-6,6-dimethyl- cyclopentapyridylcobalt dichloride was synthesized by reacting ligands with Co Cl2. Finally, the catalytic activity of these cobalt complexes towards the polymerization and oligomerization of ethylene was investigated under different reaction temperature and Al/Co molar ratio. As the results shown, upon activation with MAO, all obtained cobalt complexes just displayed moderate activity, the resulted product was polyethylene with high molecular weight; under the presence of MMAO, these cobalt catalysts showed higher activity by one order of magnitude than MAO, and the product was oligomer obeying the Schulz-Flory rule with the distribution of C4-C22.Next, we successfully synthesized 2-acetyl-7,7-dimethyl-5,6-dihydroquinolin-8-one by methylation of 2-chloro-5,6,7-trihydroquinolin-8-one with methyl iodide and then Stille coupling. When the diketone compound reacted with anilines, it was found that mono-imines were observed using xylene as the reaction solvent, while the desired diimines could be obtained when о-dichlorobenzene was used as the reaction solvent. Interestingly, when the mono-imines reacted with different anilines in о-dichlorobenzene could form the unsymmetric diimines. Then three kinds of symmetric diimines were reacted with Co Cl2, the corresponding cobalt complexes were smoothly synthesized. Finally, the catalytic activities of these three cobalt complexes towards the polymerization of ethylene was detailed studied. Upon activation with MAO, all cobalt complexes showed high activity( up to 2.95×106g PE·mol-1(Co)·h-1). |
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