1137784-97-4Relevant academic research and scientific papers
α-keto-β-diimine nickel-catalyzed olefin polymerization: Effect of ortho-aryl substituents and preparation of stereoblock copolymers
Sokolohorskyj, Anatolij,?elezník, Ond?ej,Císa?ová, Ivana,Lenz, Johannes,Lederer, Albena,Merna, Jan
, p. 2440 - 2449 (2017)
A series of α-keto-β-diimine nickel complexes (Ar-N = C(CH3)-C(O)-C(CH3)=N-Ar)NiBr2; Ar = 2,6-R-C6H3-, R = Me, Et, iPr, and Ar = 2,4,6-Me3-C6H3-) was prepared. All corresponding ligands are unstable even under an inert atmosphere and in a freezer. Stable copper complex intermediates of ligand synthesis and ethyl substituted nickel complex were isolated and characterized by X-ray. All nickel complexes were used for the polymerization of ethene, propylene, and hex-1-ene to investigate their livingness and the extent of chain-walking. Low-temperature propene polymerization with less bulky ortho-substituents was less isospecific than the one with isopropyl derivative. Propene stereoblock copolymers were prepared by iPr derivative combining the polymerization at low temperature to prepare isotactic polypropylene (PP) block and at a higher temperature, supporting chain-walking, to obtain amorphous regioirregular PP block. Alternatively, a copolymerization of propene with ethene was used for the preparation of amorphous block.
Transition metal initiators supported by ketone diimine ligands for the homopolymerization of olefins and the copolymerization of olefins with polar comonomers
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Page/Page column 7-8, (2012/08/28)
Metal-ligand combination initiators are provided which yield organometallic complexes capable of the polymerization of olefins to high molecular weight polymers. Additionally, these initiators also enable the copolymerization of olefins with functionalized comonomers. These organometallic complexes comprise of a late transition metal with a neutral chelating ligand that contains a Lewis basic functionality in conjugation with an electronically delocalized conduit extending from the metal to the functionality. This structural feature results in a highly active complex, which generates high molecular weight polymers with unique microstructures. Under particular conditions, the organometallic complexes provide for the living polymerization of monomers and comonomers.
Nickel α-Keto-β-diimine initiators for olefin polymerization
Azoulay, Jason D.,Rojas, Rene S.,Serrano, Abigail V.,Ohtaki, Hisashi,Galland, Griselda B.,Wu, Guang,Bazan, Guillermo C.
, p. 1089 - 1092 (2009/06/19)
(Figure Presented) A new ligand-metal combination (see picture, Ni green, Br brown, N blue, O red, C gray) was designed to be cationic and to benefit from removal of electron density by the action of a Lewis acid on the ligand framework. In the presence o
