Manipulation of polymer branching density in phosphine-sulfonate palladium and nickel catalyzed ethylene polymerization

Yang, Bangpei; Xiong, Shuoyan; Chen, Changle

doi:10.1039/c7py01281k

Cited by 60 publications

(36 citation statements)

References 50 publications

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“…On the other hand, the nature and length of the linker between the two centers are crucial. [27][28][29][30][31][32][33][34][35] Based on this, dinuclearity effect can control this behavior through the different structures. Bridges of various structures (polymethylene, phenylene, silane, siloxane, rigid/flexible) in multinuclear metallocene and constrained geometry complex-based catalysts have been used and reported, although in the field of late transition metal catalysts, there are more scarce reports.…”

Section: Introductionmentioning

confidence: 97%

Cooperative effect through different bridges in nickel catalysts for polymerization of ethylene

Khoshsefat

Dechal

Ahmadjo

et al. 2019

Applied Organom Chemis

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A series of mononuclear (M 1 and M 2 ) and dinuclear (C 1 -C 6 ) Ni α-diimine catalysts activated by modified methylaluminoxane were used in polymerization of ethylene. Catalyst C 2 bearing the optimum bulkiness showed the highest activity (1.6 × 10 6 g PE (mol Ni) −1 h −1 ) and the lowest short-chain branching (32.5/1000 C) in comparison to the dinuclear and mononuclear analogues.Although the mononuclear catalysts M 1 and M 2 polymerized ethylene to a branched amorphous polymer, the dinuclear catalysts led to different branched semicrystalline polyethylenes. Homogeneity and heterogeneity in the microstructure of the polyethylene samples was observed. Different trends for each catalyst were assigned to syn and anti stereoisomers. In addition, thermal behavior of the samples in the successive self-nucleation and annealing technique exhibited different orders and intensities from methylene sequences and lamellae thickness in respect of each stereoisomer behavior. Higher selectivity of hexyl branches obtained by catalyst C 2 showed a cooperative effect between the centers. The results also revealed that for catalysts C 5 and C 6 , selectivity of methyl branches led to very high endotherms and crystalline sequences with melting temperatures higher than that of 100% crystalline polyethylene indicating ethylene/propylene copolymer analogues. For catalysts C 3 and C 4 , more vinyl end groups were a result of the long distance between the Ni centers. Kinetic profiles of polymerization along with a computational study of the precatalysts and catalysts demonstrated that there is a direct relation between rate constant, energy interval of catalyst and precatalyst, and interaction energy of Et···methyl cationic active center (Et···MCC or π-Comp.). Based on this, narrow energy interval (activation energy) of precatalyst and catalyst leads to fast and higher activation rate (catalyst M 2 ), and strong interaction of ethylene and catalyst leads to high monomer uptake and productivity (catalyst C 2 ). Moreover, theoretical parameters including electron affinity, Mulliken charge on Ni, chemical potential and hardness, and global electrophilicity showed optimum values for C 2 .

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Section: Introductionmentioning

confidence: 97%

Cooperative effect through different bridges in nickel catalysts for polymerization of ethylene

Khoshsefat

Dechal

Ahmadjo

et al. 2019

Applied Organom Chemis

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“…[60] Despite the universal capabilities of the Drent-type phosphine-sulfonate palladium catalysts in copolymerization, the nickel counterparts showed undesirable reactivities when used with polar monomers. [63,64] However,v inylalkoxysilane was the only suitable polar monomer from group A. [62] Efficient copolymerization of ethylene with various comonomers in group B were achieved through catalyst improvements.…”

Section: Developments Using the Brookhart And Drent Catalystsmentioning

confidence: 99%

Emerging Palladium and Nickel Catalysts for Copolymerization of Olefins with Polar Monomers

2019

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Transition‐metal‐catalyzed copolymerization of olefins with polar monomers represents a challenge because of the large variety of substrate‐induced side reactions. However, this approach also holds the potential for the direct synthesis of polar functionalized polyolefins with unique properties. After decades of research, only a few catalyst systems have been found to be suitable for this reaction. Some major advances in catalyst development have been made in the past five years. This Minireview summarizes some of the recent progress in the extensively studied Brookhart and Drent catalyst systems, as well as emerging alternative palladium and nickel catalysts.

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“…[29] These experiments were carried out in aB uechi high pressure reactor equipped with heating-cooling jacket,o verheadm echanical stirrer and gas inlet-outlet facilities. [29] These experiments were carried out in aB uechi high pressure reactor equipped with heating-cooling jacket,o verheadm echanical stirrer and gas inlet-outlet facilities.…”

Section: C1-c4 Catalyzed Polymerization Of Ethylenementioning

confidence: 99%

Pd‐Iminocarboxylate Complexes and Their Behavior in Ethylene Polymerization

Deshmukh

Gaikwad

Gonnade

et al. 2020

Chemistry An Asian Journal

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Designingc o-catalyst-free late transition metal complexes for ethylene polymerization is ac hallenging task at the interface of organometallic and polymerc hemistry. Herein, as et of new,co-catalyst-free,s ingle-component catalytic systemsf or ethylene polymerizationh ave been unraveled. Treatmento fa nthranilica cid with various aldehydes produced four iminocarboxylate ligands (L1-L4)i nv ery good to excellent yield (75-92 %). The existence of 2-((2-methoxybenzylidene)amino) benzoica cid (L1)h as been unambiguously demonstrated using NMR spectroscopy,M Sa nd single-crystal X-ray diffraction. An eutralP d-iminocarboxylate complex [{N O}PdMe(L1)] (N O = k 2 -N,O-ArCHNC 6 H 4 CO 2 with Ar = 2-MeOC 6 H 4 ) C1 was prepared by treating stoichiometric amount of L1.Na with palladium precursor.T he identity of C1 was confirmed by 1-2D NMR spectroscopy and singlecrystal X-ray diffraction studies. Along the same lines,p alladium complexes C2-C4 were prepared from ligands L2-L4 respectively.I n-situ high-pressure NMR investigations revealed that these Pd complexes are amenable to ethylene insertiona nd undergo facile b-H elimination to produce propylene. These palladium complexes were then evaluated in ethylene polymerizationr eaction and various reactionp arameters were screened. When C1-C4 were exposed to ethylene pressures of 10-50bar,f ormationo fl ow-molecularweightpolyethylene wasobserved.

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Manipulation of polymer branching density in phosphine-sulfonate palladium and nickel catalyzed ethylene polymerization

Abstract: A series of palladium and nickel catalysts bearing heteroaryl-aryl moieties were prepared and applied to ethylene polymerization and copolymerization reactions.

Cited by 60 publications

References 50 publications

Cooperative effect through different bridges in nickel catalysts for polymerization of ethylene

Cooperative effect through different bridges in nickel catalysts for polymerization of ethylene

Emerging Palladium and Nickel Catalysts for Copolymerization of Olefins with Polar Monomers

Pd‐Iminocarboxylate Complexes and Their Behavior in Ethylene Polymerization

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