含吸电子基团配体的α-二亚胺-Ni(Ⅱ)上乙烯聚合反应性能

Catalytic Properties of α-Diimine-Ni(II) Catalyst Containing Electron Withdrawing Substituent for Ethylene Polymerization

合成了一种新型的含溴α-二亚胺配体及其Ni配合物,并采用核磁共振氢谱、核磁共振碳谱、元素分析、傅里叶变换红外光谱和X射线光电子能谱进行了表征.同时以二乙基氯化铝为助催化剂用于乙烯聚合反应,考察了温度、Al/Ni摩尔比和配体结构对聚合反应性能的影响.结果表明,在25oC,Al/Ni摩尔比为600时,该催化剂活性最高,可达3.73×107g/(mol·h·MPa),与不含吸电子基团Br的同类催化剂活性相当,且催化剂热稳定性和产物聚乙烯支化度明显提高.

A new Br-substituted a-diimine ligand and its corresponding Ni（Ⅱ） complex, {bis[N,N＇-（4-bromo-2, 6-dimethylphenyl）imino] acenanhthene}dibromonicke （2） were successfully synthesized and characterized by 1H and 13C nuclear magnetic resonance, elementalanalysis, Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. The catalytic system, complex 2/dlethylalumlnmm chloride （DEAC） showed higher activity for ethylene polymerization. The highest activity （3.73 x 107g/（mol.h.MPa）） was obtained with the A1/Ni molar ratio of 600 at 25 ℃. The catalyst containing electron-withdrawing group Br showed better thermodynamic stability and almost the same catalytic activity compared with the Br-free catalyst. Branching degree was increased in the presence of electron-withdrawing group Br.