Recent advancements in α-diimine-nickel and -palladium metal ethylene polymerization catalysts: catalyst structure-activity and -polymer properties relationship

2021 ◽  
pp. 110783
Author(s):  
Muhammad Qasim ◽  
Muhammad Sohail Bashir ◽  
Shahid Iqbal ◽  
Qaiser Mahmood
Keyword(s):  
Ethylene Polymerization ◽  
Polymerization Catalysts ◽  
Catalyst Structure ◽  
Structure Activity ◽  
Polymer Properties ◽  
Palladium Metal

scholarly journals Iminopyridine Ni(II) Catalysts Affording Oily Hyperbranched Oligoethylenes and/or Crystalline Polyethylenes Depending on the Reaction Conditions: Possible Role of In Situ Catalyst Structure Modifications

2021 ◽  
Author(s):  
Ilaria D'Auria ◽  
Zeinab Saki ◽  
Claudio Pellecchia
Keyword(s):  
Ethylene Polymerization ◽  
Active Species ◽  
Polymerization Catalysts ◽  
Reaction Conditions ◽  
Catalyst Structure ◽  
Variable Content ◽  
Peculiar Behavior ◽  
Number Of Branches

Nickel-based ethylene polymerization catalysts have unique features, being able to produce macromolecules with a variable content of branches, resulting in polymers ranging from semicrystalline plastics to elastomers to hyperbranched amorphous waxes and oils. In addition to Brookhart's α-diimine catalysts, iminopyridine Ni(II) complexes are among the most investigated systems. We report that Ni(II) complexes bearing aryliminopyridine ligands with bulky substituents both at the imino moiety and in the 6-position of pyridine afford either hyperbranched low molecular weight polyethylene oils or prevailingly linear crystalline polyethylenes or both depending on the ligand structure and the reaction conditions. The formation of multiple active species in situ is suggested by analysis of the post-polymerization catalyst residues, showing the partial reduction of the imino function. Some related arylaminopyridine Ni(II) complexes were also synthesized and tested, showing a peculiar behavior, i.e. the number of branches of the produced polyethylenes increases while ethylene pressure increases.

Doubly fused N,N,N-Iron Ethylene Polymerization Catalysts appended with Fluoride Substituents; probing catalytic performance via a combined experimental and MLR study

2021 ◽  
Author(s):  
Qiuyue Zhang ◽  
Wenhong Yang ◽  
Zheng Wang ◽  
Gregory A. Solan ◽  
Tongling Liang ◽  
...  
Keyword(s):  
Ethylene Polymerization ◽  
Catalytic Performance ◽  
Chloride Complex ◽  
Polymerization Catalysts

Access to six examples of α,α’-bis(imino)-2,3:5,6-bis(pentamethylene)pyridine-iron(II) chloride complex, [2,3:5,6-{C4H8C(N(2-R1-4-R3-6-R2C6H2)}2C5HN] (R1 = Me, R2 = R3 = CH(p-FPh)2 Fe1; R1 = Et, R2 = R3 = CH(p-FPh)2 Fe2; R1 = iPr,...

Active O,Npy,N-Titanium(IV) Fluoride Precatalysts for Ethylene Polymerization: Exploring “Fluoride Effects” on Polymer Properties and Catalytic Performance

2016 ◽  
Vol 35 (9) ◽  
pp. 1183-1191 ◽  
Author(s):  
Luka A. Wright ◽  
Eric G. Hope ◽  
Gregory A. Solan ◽  
Warren B. Cross ◽  
Kuldip Singh
Keyword(s):  
Ethylene Polymerization ◽  
Catalytic Performance ◽  
Polymer Properties
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