Lewis acid-induced homo- and heterogeneous nickel catalysts for ethylene polymerization and copolymerization with polar monomers

Polymer Chemistry, Journal Year: 2024, Volume and Issue: 15(7), P. 631 - 638

Published: Jan. 1, 2024

By introducing soluble and supported Lewis acids, homogeneous heterogeneous nickel-catalyzed ethylene (co)polymerization was designed studied.

Language: Английский

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Switchable Synthesis of Ethylene/Acrylate Copolymers by a Dinickel Catalyst: Evidence for Chain Growth on Both Nickel Centers and Concepts of Cation Exchange Polymerization

ACS Catalysis, Journal Year: 2024, Volume and Issue: 14(7), P. 5260 - 5268

Published: March 25, 2024

A dinickel complex, X-Ni2, was developed and demonstrated to have a high performance in ethylene/acrylate copolymerization. Further mechanistic studies revealed that X-Ni2 performs acrylate insertion at both Ni centers distinct rates. Addition of NaBArF24 leads 1:1 binding serves as switch for tuning catalytic activity, copolymer MW incorporation. NMR cation binding, when present substoichiometric amounts, suggest dynamic process involving exchange. This phenomenon provides an alternative strategy controlling chain growth polar polyolefin synthesis probed herein.

Language: Английский

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Control of chain transfer and chain walking by tailored metal–π interactions in polymerization catalysis

Journal of Catalysis, Journal Year: 2024, Volume and Issue: 435, P. 115550 - 115550

Published: May 15, 2024

Language: Английский

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Suppression of Chain Walking and Chain Transfer in Ethylene (Co)Polymerization with Iminodibenzyl Substituents Containing Second Coordination Spheres

Macromolecules, Journal Year: 2024, Volume and Issue: 57(11), P. 5262 - 5270

Published: May 29, 2024

Chain walking and chain transfer are the two most important events that determine structure molecular weight of resulting polyolefin in imine-based late transition metal-catalyzed ethylene (co)polymerization. In this study, we have demonstrated nitrogen-containing iminodibenzyl substituents effective suppression during α-diimine Ni(II)- Pd(II)-catalyzed For purpose, several Ni(II) Pd(II) complexes with N-diphenyl or been designed, prepared, described. case nickel-catalyzed polymerization, catalyst exhibited higher activities yielded polyethylenes orders magnitude weights than catalyst. Similar observations were also found polymerization copolymerization methyl acrylate catalyzed by corresponding palladium catalysts. Compared to dibenzosuberyl catalysts, catalysts an excellent ability suppress process produced (co)polymers significantly lower branching densities It was proposed observed phenomenon is caused second coordination sphere effects substituents.

Language: Английский

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Controlled Oligomerization in Water to Hyperbranched Ethylene Oligomers

Chemical Communications, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 1, 2025

We report the oligomerization of ethylene using iminopyridyl Pd( ii ) catalysts in water, leading to synthesis hyperbranched polyethylene oils with long-chain branching and low viscosity.

Language: Английский

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Flexible α‐Diimine Ni(II) and Pd(II) Catalysts Featuring Backbone and Axial Cycloalkyl Substituents in Ethylene (Co)polymerization

Journal of Polymer Science, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 5, 2025

ABSTRACT Recently, axial flexible substituents have found widespread application in ethylene (co)polymerization catalyzed by late transition metals, yielding impressive results. In this research, we designed and synthesized a novel class of α‐diimine Ni(II) Pd(II) catalysts, distinguished their backbones that both incorporate cycloalkyl moieties. During nickel‐catalyzed polymerization, these nickel catalysts demonstrated high activity (well above 10 6 g/(mol Ni·h)) thermal stability, producing polyethylenes with very molecular weights (up to 1022 kg/mol) branching densities 103/1000C). Interestingly, the catalyst reported study exhibits higher compared classic rigid backbones. The resultant polyethylene materials exhibited outstanding mechanical properties elastic recovery (with strain (SR) up 79%), qualifying them as high‐performance thermoplastic elastomers. contrast, during palladium‐catalyzed palladium showed moderate (level 5 Pd·h)) generated 99/1000C) 203 kg/mol). case copolymerization methyl acrylate (MA), was notably reduced homopolymerization, resulting E‐MA copolymers lower densities. However, under experimental conditions, successfully obtained significant incorporation (1.53–4.54 mol%) MA. It is worth noting cyclohexyl group displayed superior chain transfer inhibition systems cyclopentyl group. Nevertheless, notable difference observed influence on density regulation: system, facilitated formation branching, while it had opposite effect when

Language: Английский

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Axial Anagostic Interaction in α-Diimine Nickel Catalysts: An Ultraefficient Occupation Strategy in Suppressing Associative Chain Transfers to Achieve UHMWPEs

Macromolecules, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 10, 2025

Language: Английский

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Efficient Synthesis of Polyethylene Wax Using 8-(Arylimino)-5,6,7-Trihydroquinoline Sio 2 -Supported Heterogeneous Nickel Catalysts

Published: Jan. 1, 2025

Language: Английский

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Efficient synthesis of polyethylene wax using 8-(arylimino)-5,6,7-trihydroquinoline SiO2-supported heterogeneous nickel catalysts

Polymer, Journal Year: 2025, Volume and Issue: unknown, P. 128367 - 128367

Published: April 1, 2025

Language: Английский

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Fluoro-enriched α-diimine nickel precatalysts for enhanced thermostability in synthesis of polyethylene elastomer

European Polymer Journal, Journal Year: 2025, Volume and Issue: unknown, P. 114004 - 114004

Published: May 1, 2025

Language: Английский

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