Mechanistic Insights on the Controlled Switch from Oligomerization to Polymerization of 1-Hexene Catalyzed by an NHC-Zirconium Complex

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• 作者：Emmanuelle Despagnet-Ayoub ; Michael K. Takase ; Lawrence M. Henling ; Jay A. Labinger ; John E. Bercaw
• 刊名：Organometallics
• 出版年：2015
• 出版时间：October 12, 2015
• 年：2015
• 卷：34
• 期：19
• 页码：4707-4716
• 全文大小：514K
• ISSN：1520-6041

文摘

The benzimidazolylidene zirconium complex 1 switches from an oligomerization (without additive) to a polymerization catalyst by addition of an L-type ligand such as trimethylphosphine, while larger phosphines or amines completely inhibit catalysis. On the basis of the regioselectivity of the oligomers/polymers obtained, the time profiles of reactions as a function of added ligand, and the molecular structures of several cationic zirconium complexes, we propose a mechanistic framework for interpreting this complex catalytic behavior.