Binding modes of a dimethyliminopentanone ligand on nickel pre-catalysts toward olefin polymerization

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• 作者：Brycelyn M. Boardman ; Guang Wu ; Rene Rojas ; Guillermo C. Bazan
• 关键词：Nickel ; Homogeneous catalysis ; Polyethylene ; Binding modes
• 刊名：Journal of Organometallic Chemistry
• 出版年：2009
• 出版时间：15 April 2009
• 年：2009
• 卷：694
• 期：9-10
• 页码：1380-1384
• 全文大小：475 K

文摘

Nickel complexes prepared using a 4-(2,6-diisopropylphenylimino)-3,3-dimethylpentan-2-one ligand framework are shown. The potassium salt of the ligand is obtained by deprotonation with KH in diethyl ether. Potassium 4-(2,6-diisopropylphenylimino)-3,3-dimethyl-pent-2-en-2-olate can then be reacted with Ni(PMe₃)₂(η¹-CH₂Ph)Cl to yield 4-(2,6-diisopropylphenylimino)-3,3-dimethyl-pent-2-en-2-olato-κ¹O](η¹-CH₂Ph)(PMe₃)₂Ni (1). The potassium salt of the ligand can also be reacted with Ni(PMe₃)(η³-CH₂Ph)Cl to yield bis(4-(2,6-diisopropylphenylimino)-3,3-dimethyl-pent-2-en-2-olato-κ²N,O](η¹-CH₂Ph)₂Ni₂ (2) or 4-(2,6-diisopropylphenylimino)-3,3-dimethyl-pent-2-en-2-olato-κ²N,O](η¹-CH₂Ph)(PMe₃)Ni (3), depending on the reaction conditions. The addition of five equivalents of B(C₆F₅)₃ to 1, 2, or 3 yields catalytically active species for the homopolymerization of ethylene. The polymer products are described by a single molecular weight distribution, consistent with the presence of a single active site.