Indole-bridged bisphosphine-monoxide palladium catalysts for ethylene polymerization and copolymerization with polar monomers

2020 ◽  
Vol 11 (15) ◽  
pp. 2740-2748 ◽  
Author(s):  
Kangkang Li ◽  
Junhao Ye ◽  
Zhen Wang ◽  
Hongliang Mu ◽  
Zhongbao Jian
Keyword(s):  
Palladium Catalysts ◽  
Ethylene Polymerization ◽  
Molecular Weights ◽  
Polar Monomers

Novel indole-based C–N-bridged bisphosphine-monoxide palladium catalysts enable ethylene polymerization with completely different activities and molecular weights and copolymerization with polar comonomers.

Sterically very bulky aliphatic/aromatic phosphine-sulfonate palladium catalysts for ethylene polymerization and copolymerization with polar monomers

2019 ◽  
Vol 10 (4) ◽  
pp. 546-554 ◽  
Author(s):  
Jian Xia ◽  
Yixin Zhang ◽  
Xiaoqiang Hu ◽  
Xin Ma ◽  
Lei Cui ◽  
...  
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Palladium Catalysts ◽  
Ethylene Polymerization ◽  
Polar Monomers

Copolymerization of ethylene and polar monomers with significantly high molecular weight and activity was achieved using bulky aliphatic/aromatic phosphine-sulfonate palladium catalysts.

Versatile PNPO ligands for palladium and nickel catalyzed ethylene polymerization and copolymerization with polar monomers

2021 ◽  
Vol 393 ◽  
pp. 281-289
Author(s):  
Chen Zou ◽  
Daohong Liao ◽  
Wenmin Pang ◽  
Min Chen ◽  
Chen Tan
Keyword(s):  
Ethylene Polymerization ◽  
Polar Monomers

scholarly journals Ethylene Polymerization and Copolymerization with Polar Monomers by Benzothiophene-bridged BPMO-Pd Catalysts

2019 ◽  
Vol 38 (6) ◽  
pp. 579-586 ◽  
Author(s):  
Hong-Liang Mu ◽  
Jun-Hao Ye ◽  
Guang-Lin Zhou ◽  
Kang-Kang Li ◽  
Zhong-Bao Jian
Keyword(s):  
Ethylene Polymerization ◽  
Pd Catalysts ◽  
Polar Monomers

scholarly journals Molecular weight control in organochromium olefin polymerization catalysis by hemilabile ligand–metal interactions

2016 ◽  
Vol 12 ◽  
pp. 1372-1379 ◽  
Author(s):  
Stefan Mark ◽  
Hubert Wadepohl ◽  
Markus Enders
Keyword(s):  
Ethylene Polymerization ◽  
Weight Control ◽  
Transfer Reactions ◽  
High Catalytic Activity ◽  
Co Catalyst ◽  
Metal Centers ◽  
Molecular Weights ◽  
Metal Interactions ◽  
Polymerization Catalysis ◽  
Very High

A series of Cr(III) complexes based on quinoline-cyclopentadienyl ligands with additional hemilabile side arms were prepared and used as single-site catalyst precursors for ethylene polymerization. The additional donor functions interact with the metal centers only after activation with the co-catalyst. Evidence for this comes from DFT-calculations and from the differing behavior of the complexes in ethylene polymerization. All complexes investigated show very high catalytic activity and the additional side arm minimizes chain-transfer reactions, leading to increase of molecular weights of the resulting polymers.

Binding of polar monomers in the complexes with organometallic ethylene polymerization catalysts — Natural orbitals for chemical valence and energy decomposition analysis

2009 ◽  
Vol 87 (7) ◽  
pp. 1039-1054 ◽  
Author(s):  
Monika Srebro ◽  
Mariusz Mitoraj ◽  
Artur Michalak
Keyword(s):  
Ethylene Polymerization ◽  
Binding Mode ◽  
Transition Metal Catalysts ◽  
Energy Decomposition Analysis ◽  
Orbital Interaction ◽  
Energy Decomposition ◽  
Natural Orbitals ◽  
Interaction Terms ◽  
Back Bonding ◽  
Polar Monomers

The binding mode of polar monomers in complexes with late-transition-metal catalysts for ethylene polymerization was studied by density functional theory (DFT) calculations. The Ziegler–Rauk energy decomposition scheme was used to characterize the geometry distortion and steric and orbital-interaction terms in the bonding energy, while Natural Orbitals for Chemical Valence (NOCV) were applied to describe the donation and back-bonding components of the bond between the monomer and the catalyst. The NOCV analysis allowed for comparison of the donor–acceptor properties of different monomers in the σ- and π-complexes. The complexes with the model, cationic Ni– or Pd–diimine catalysts, N^N–Ni(H)+ and N^N–Pd(H)+, and the neutral Ni–anilinotropone system, N^O–Ni(H), were investigated. The monomers studied included: simple olefins (Et and Pr); examples of oxygen- and nitrogen-containing polar monomers (methyl acrylate (MA), vinyl acetate (VAc), their fluorinated derivatives (FMA, FVAc), vinyl ether (VE), acrylonitrile (AN), and β-butenoic nitrile (BN); vinyl and allyl amines (VAm, PrAm); and a tertiary dimethyl vinyl amine (MVAm). The results demonstrate that the metal-based fragment has a significant influence on the relative stability of the σ- and π-complexes; the π-binding mode increases in the following order: N^N–Ni(H)+ < N^N–Pd(H)+ < N^O–Ni(H). The results of the Ziegler–Rauk bond-energy decomposition indicate that for some monomers (MA, FMA, VAc, AN, VAm, MVAm) the preference of the coordination mode has a steric (electrostatic and Pauli) origin. For other monomers (VE, FVAc, BN, PrAm) the changes in the orbital-interaction terms are important as well. The results of the NOCV analysis indicate that for both, σ- and π-coordination modes there exist components describing σ-donation and π-back-bonding. The sequences of σ-donor and π-acceptor properties of monomers in the π-complexes as well as σ-complexes are similar for the considered catalysts.

scholarly journals 6-Arylimino-2-(2-(1-phenylethyl)naphthalen-1-yl)-iminopyridylmetal (Fe and Co) Complexes as Highly Active Precatalysts for Ethylene Polymerization: Influence of Metal and/or Substituents on the Active, Thermostable Performance of Their Complexes and Resultant Polyethylenes

Molecules ◽  
2020 ◽  
Vol 25 (18) ◽  
pp. 4244 ◽  
Author(s):  
Wenhua Lin ◽  
Liping Zhang ◽  
Jiahao Gao ◽  
Qiuyue Zhang ◽  
Yanping Ma ◽  
...  
Keyword(s):  
Elevated Temperature ◽  
Single Crystal ◽  
Ethylene Polymerization ◽  
Active Species ◽  
Single Site ◽  
X Ray ◽  
X Ray Crystallography ◽  
Molecular Weights ◽  
Highly Active ◽  
Cobalt Center

A series of 6-arylimino-2-(2-(1-phenylethyl)naphthalen-1-yl)iminopyridines and their iron(II) and cobalt(II) complexes (Fe1–Fe5, Co1–Co5) were synthesized and routinely characterized as were Co3 and Co5 complexes, studied by single crystal X-ray crystallography, which individually displayed a distorted square pyramidal or trigonal bipyramid around a cobalt center. Upon treatment with either methyluminoxane (MAO) or modified methyluminoxane (MMAO), all complexes displayed high activities regarding ethylene polymerization even at an elevated temperature, enhancing the thermostability of the active species. In general, iron precatalysts showed higher activities than their cobalt analogs; for example, 10.9 × 106 g(PE) mol−1 (Co) h−1 by Co4 and 17.0 × 106 g(PE) mol−1 (Fe) h−1 by Fe4. Bulkier substituents are favored for increasing the molecular weights of the resultant polyethylenes, such as 25.6 kg mol−1 obtained by Co3 and 297 kg mol−1 obtained by Fe3. A narrow polydispersity of polyethylenes was observed by iron precatalysts activated by MMAO, indicating a single-site active species formed.

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