A Second‐Coordination‐Sphere Strategy to Modulate Nickel‐ and Palladium‐Catalyzed Olefin Polymerization and Copolymerization. Issue 38 (7th August 2017)

• Record Type: Journal Article
• Authors: Li, Min; Wang, Xingbao; Luo, Yi; Chen, Changle
• Is Part Of: Angewandte Chemie international edition. Volume 56:Issue 38(2017)
• Page Start: 11604
• Page End: 11609
• Publication Date: 2017-08-07
• Subjects: copolymerization -- olefin polymerization -- palladium catalysts -- polar monomers -- second coordination sphere; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201706249
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: Transition‐metal‐catalyzed copolymerization reactions of olefins with polar‐functionalized comonomers are highly important and also highly challenging. A second‐coordination‐sphere strategy was developed to address some of the difficulties encountered in these copolymerization reactions. A series of α‐diimine ligands bearing nitrogen‐containing second coordination spheres were prepared and characterized. The properties of the corresponding nickel and palladium catalysts in ethylene polymerizations and copolymerizations were investigated. In the nickel system, significant reduction in polymer branching density was observed, while lower polymer branching densities, as well as a wider range of polar monomer substrates, were achieved in the palladium system. Control experiments and computational results reveal the critical role of the metal−nitrogen interaction in these polymerization and copolymerization reactions. Abstract : Long arm of the ligand : A second‐coordination‐sphere strategy was developed to address difficulties encountered in coordination copolymerization of olefins with polar monomers. Control experiments and computational results reveal the critical role of the interaction between the metal center and the second coordination sphere of the ligand.