Chiral Naphthyl-伪-diimine Nickel(II) Catalysts Bearing sec-Phenethyl Groups: Chain-Walking Polymerization of Ethylene at High Temperature and Stereoselective Polymerization of Methyl Methacryla

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• 作者：Jianchao Yuan ; Fuzhou Wang ; Weibing Xu ; Tongjian Mei ; Jing Li ; Bingnian Yuan ; Fengying Song ; Zong Jia
• 刊名：Organometallics
• 出版年：2013
• 出版时间：July 22, 2013
• 年：2013
• 卷：32
• 期：14
• 页码：3960-3968
• 全文大小：488K
• 年卷期：v.32,no.14(July 22, 2013)
• ISSN：1520-6041

文摘

A series of new naphthyl-伪-diimine nickel(II) complexes, {bis[N,N鈥?(1-naphthyl)imino]-1,2-dimethylethane}dibromonickel (2a), {bis[N,N鈥?(2-methyl-1-naphthyl)imino]-1,2-dimethylethane}dibromonickel (2b), {bis[N,N鈥?(2-sec-phenethyl-1-naphthyl)imino]-1,2-dimethylethane}dibromonickel (rac-(RR/SS)-2c), {bis[N,N鈥?(2-methyl-1-naphthyl)imino]acenaphthene}dibromonickel (2d), and {bis[N,N鈥?(2-naphthyl)imino]-1,2-dimethylethane}dibromonickel (2e), were synthesized and characterized. The crystal structures of ligands 1b, rac-(RR/SS)-1c, 1d, 1e and their representative complexes rac-(RR/SS)-2c and 2d were determined by X-ray crystallography. These complexes, activated by diethylaluminum chloride (DEAC), were tested in the polymerization of ethylene and methyl methacrylate under mild conditions. Complex rac-(RR/SS)-2c, bearing chiral bulky sec-phenethyl groups in the o-naphthyl position, activated by diethylaluminum chloride (DEAC) shows highly catalytic activity for the polymerization of ethylene (2.81 脳 10⁶ g PE/((mol of Ni) h bar)) and produced branched polyethylene (75 methyl, 9 ethyl, 5 propyl, and 19 butyl or longer branches/1000 C at 40 掳C). Interestingly, rac-(RR/SS)-2c could produce syndiotactic PMMA at low temperature (鈭?0 掳C: rr 88.75%, mr 7.26%, mm 3.99%).