Copolymerization of Ethylene with Methyl Methacrylate with Neutral Nickel(II) Complexes Bearing β-Ketoiminato Chelate Ligands

Li, Xiaofang; Li, Yang-Guo; Li, Yuesheng; Yan-xiang, Chen; Hu, Ninghai

doi:10.1021/om049080w

Cited by 93 publications

(56 citation statements)

References 39 publications

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“…However, although the most expensive palladium α‐diimine catalysts were able to produce ethylene‐acrylate or propene‐acrylate copolymers under certain experimental conditions, their nickel α‐diimine counterparts were easily poisoned by polar comonomers 5, 6. In contrast, nickel catalysts based on neutral ligands exhibiting a mixed donor atom set (N,O or P,O) are a priori good candidates for copolymerization due to their less electrophilic center 7–11. Thus, by increasing the positive charge density at the metal center, we would expect to see an increase in activity as preserving the capacity of the aforementioned catalysts to incorporate polar comonomers.…”

Section: Introductionmentioning

confidence: 99%

Density functional study for the polymerization of ethylene monomer using a new nickel catalyst

Ramos

Cruz

Martínez‐Salazar

et al. 2010

J. Polym. Sci. A Polym. Chem.

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The present computational study was designed to study the polymerization of ethylene catalyzed by a new Nibased PymNox organometallic compound. Recently, we have synthesized and tested the behavior of this type of catalyst in olefin polymerization. It has been experimentally observed that the unsubstituted catalyst Ni2 (aldimino PymNox catalyst) is less active than the methyl substituted Ni1 (acetaldimino PymNox catalyst) analogue. The reactivity of both catalysts was examined using density functional theory (DFT) models. Our results indicate that the methyl substituted Ni1 introduces some additional steric hindrance that probably renders a more suitable catalyst conformation for the monomer incorporation.

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Section: Introductionmentioning

confidence: 99%

Density functional study for the polymerization of ethylene monomer using a new nickel catalyst

Ramos

Cruz

Martínez‐Salazar

et al. 2010

J. Polym. Sci. A Polym. Chem.

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“…Although early transition metal catalyst currently dominates the industrial process of olefin polymerization, there has been a trend toward the development of the catalysts containing late transition metal elements because of the potential to yield polymers with different microstructures and more tolerant of functionalized monomers 1–32. An important advance in late transition metal catalyst for olefin polymerization was described by Brookhart and coworkers, who showed that Ni(II) and Pd(II) complexes incorporating bulky α‐diimine ligands are capable of polymerizing ethylene to high molecular weight branched polyethylenes 5–9…”

Section: Introductionmentioning

confidence: 99%

Ethylene polymerization by (α‐diimine)nickel(II) complexes bearing different substituents on para‐position of imines activated with MMAO

Liu

et al. 2008

J of Applied Polymer Sci

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A series of (a-diimine)nickel(II) complexes [ArN 5 C(Nap)C 5 NAr]NiBr 2 (Nap 5 1,8-naphthdiyl, Ar 5 2,6-Me 2 C 6 H 3 , 3a; Ar 5 2,4,6-Me 3 C 6 H 2 3b; Ar 5 2,6-Me 2 -4-tBuC 6 H 2 , 3c; Ar 5 2,6-Me 2 -4-BrC 6 H 2 , 3d; Ar 5 2,6-Me 2 -4-ClC 6 H 2 , 3e; Ar 5 2,6-iPr 2 C 6 H 3 , 3f; Ar 5 2,4,6-iPr 3 C 6 H 2 , 3g; Ar 5 2,6-iPr-4-BrC 6 H 2 , 3h) have been synthesized, characterized, and investigated as precatalysts for ethylene polymerization in the presence of modified methylaluminoxane (MMAO). The substituents of a-diimine ligands and their positions located significantly influence catalyst activity and polymer property. It is found that the catalytic activities of the nickel complex/MMAO systems and the microstructure of the polymer obtained are dominated by not only hindering effect of ortho-position substituents but also electronical effect of para-position substituents.

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“…Similar anilinoenolate Ni complexes also promote copolymerization of ethylene with methyl methacrylate [110][111][112][113]. The complexes having ligand with acyclic structure require B(C 6 F 5 ) 3 for the activation, whereas the complex of the ligand having Chart 4.6 Ni catalysts with salicylaldimine ligands cyclic substituent (6e) acts as a single-component catalyst.…”

Section: Catalyst Having An Imine-aryloxo (Phenoxyimine) Type Ligandsmentioning

confidence: 99%

Olefin Polymerization with Non-metallocene Catalysts (Late Transition Metals)

Takeuchi

2014

Organometallic Reactions and Polymerization

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Diimine Pd and Ni complexes catalyze the polymerization of ethylene, propylene, and a-olefins. The reaction involves isomerization of the growing terminal (chain walking) and, as its result, produces highly branched polyethylene and poy(a-olefin)s having a smaller number of the alkyl substituents than expected from the monomer structure. Ni complexes with salicylaldimine or iminocarboxamide ligands and Pd complexes with phosphinesulfonate ligands are used as single component catalysts for ethylene polymerization. Especially, the latter catalysts show tolerance towards polar functional groups and promote copolymerization of ethylene with wide varieties of polar monomers. The Pd and Ni complexes are able to catalyze ethylene polymerization in aqueous media to yield polyethylene particles. Fe and Co complexes with bis(imino)pyridine ligands show high catalytic activity for ethylene polymerization to yield linear polyethylene. Complexes of the metals such as Rh, Ir, Ru, and Ag were revealed to become catalytically active by proper design of the ligand. Not only monometallic complexes but also bimetallic or multimetallic complexes are used for ethylene polymerization. Late transition metal complexes catalyze selective cyclopolymerization of non-conjugated dienes and trienes to afford the polymers with cycloalkane groups with controlled stereochemistry.

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Copolymerization of Ethylene with Methyl Methacrylate with Neutral Nickel(II) Complexes Bearing β-Ketoiminato Chelate Ligands

Cited by 93 publications

References 39 publications

Density functional study for the polymerization of ethylene monomer using a new nickel catalyst

Density functional study for the polymerization of ethylene monomer using a new nickel catalyst

Ethylene polymerization by (α‐diimine)nickel(II) complexes bearing different substituents on para‐position of imines activated with MMAO

Olefin Polymerization with Non-metallocene Catalysts (Late Transition Metals)

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