Synthesis Of Imine Ligands And Complexes With Conjugate Structure

With the development of the times and social progress, people demand more and moreon the polyethylene material. Although domestic polyethylene industry is developing steadily,there is still a long way to go to reach the technical level of the developed countries in theworld, therefore we should devote to researches related to polyethylene. Polyethylene catalystis one of key drivers for the synthesis of polyethylene into ethylene polymerization. In therecent years, late transition metal catalysts for its unique advantages aroused researchers’attention, especially alpha two imino transition metal catalyst with a conjugate structureshows single activity center, high catalytic activity and at the same time can control theproducts on the molecular level. This paper mainly attempts to synthesize double iminecomplexes with conjugated structure based on alpha two imino transition metal catalysts witha conjugated structure and meanwhile tries to explore its catalytic activity.This paper mainly depends on the past researches of sub-type ligand catalyst withconjugated structure and based on the Schiff’s characteristics of alkali reaction, being boldlycreative, we choose phthalaldehyde as main material to synthesize diimine late transitionmetal complexes. First of all, we should have the ability to choose the right amine compoundswhich can react with phthalaldehyde. In this paper, we choose N-phenylethylenediamine,2-aminopyridine and o-aminophenol as the right amine compounds and let them react withphthalaldehyde respectively. Throughout this experiment, we try to explore the feasibility ofproducing ligand when o-Phenylenediamine, m-phenylenediamine, phenylhydrazine,6-Amino-2,4-dimethylpyridine,2,6-dimethylaniline and N-(2-Aminoethyl)morpholinerespectively react with phthalaldehyde. Kinds of Double imine ligand with conjugatedstructure are synthesized via condensation and then we use ligand L1, L2and L3reactingwith NiBr2(DME) and CoCl2,which can synthesize diimine complexes a~e. Then accordingto the analysis method of1H NMR、1C NMR、IR, we try to analyze the structures of theformed ligand and the complexes. Finally, we select four better complexes a~d for ethylenepolymerization studies. We explore to find out the condition and method of forming highactivity catalysts based on changing temperature, the amounts of cocatalyst and some otherfactors. All reactions were carried out at40°C and1500equiv. of EASC, Nickel complexes aexhibit high activity, and success of catalytic polymerization of ethylene to high molecularweight polyethylene.