Remote dibenzocycloheptyl substitution on a bis(arylimino)pyridyl-iron ethylene polymerization catalyst; enhanced thermal stability and unexpected effects on polymer properties

2021 ◽  
Author(s):  
Liwei Guo ◽  
Wenjuan Zhang ◽  
Furong Cao ◽  
Youshu Jiang ◽  
Randi Zhang ◽  
...  

Four examples of para-dibenzocycloheptyl-substituted 2,6-bis(arylimino)pyridyl-iron(II) chloride complexes, [2,6-{(2-R1,4-(C15H13),6-R2C6H2)N=CMe}2C5H3N]FeCl2 (R1 = R2 = Me Fe1, Et Fe2, iPr Fe3, R1 = Me, R2 = Et Fe4), have been synthesized and characterized...

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

2012 ◽  
Vol 31 (14) ◽  
pp. 5039-5048 ◽  
Author(s):  
Wenjuan Zhang ◽  
Wenbin Chai ◽  
Wen-Hua Sun ◽  
Xinquan Hu ◽  
Carl Redshaw ◽  
...  

RSC Advances ◽  
2019 ◽  
Vol 9 (13) ◽  
pp. 7420-7431 ◽  
Author(s):  
Fatemeh Poorsank ◽  
Hassan Arabi ◽  
Nona Ghasemi Hamedani

In this study, bis(benzoyloxy)dimethylsilane (SDE) was developed as a non-phthalate selectivity control agent (internal donor (ID) and external donor (ED)) in MgCl2-supported Ziegler–Natta (ZN) systems for polypropylene polymerization.


2017 ◽  
Vol 95 (4) ◽  
pp. 363-370 ◽  
Author(s):  
Jianlong Sun ◽  
David J. Berg ◽  
Brendan Twamley

The synthesis of tetrabenzo[a,c,g,i]fluorenyl (Tbf) yttrium dialkyl complexes, (Tbf)Y(CH2SiMe3)2(L) (L = tetrahydrofuran (THF), 1; L = bipy, 2), by direct protonolysis of the tris(alkyl) complex, Y(CH2SiMe3)3(THF)2, are reported. The X-ray crystal structures of 1 and 2 display the helical twisting typically observed for the Tbf ligand. Dynamic nuclear magnetic resonance (NMR) studies on 1 show a barrier to Tbf helical inversion (epimerization or “wagging”) of 38.1 ± 0.5 kJ mol−1. The reaction of 1 with acidic hydrocarbons such as 1,3-bis(trimethylsilyl)cyclopentadiene or trimethylsilylacetylene results in protonolysis to form the mixed Cp derivative [(Tbf){C5H3(SiMe3)2}Y(CH2SiMe3)(THF)] (3) or [(Tbf)Y(CCSiMe3)2(THF)]n (4), respectively. In the case of 4, a small amount of the trinuclear cluster (Tbf)Y3(μ3-CCSiMe3)2(μ2-CCSiMe3)3(CCSiMe3)3(THF)2 (5) was isolated and characterized by X-ray crystallography. Dialkyl 1 undergoes smooth insertion of trimethylsilyl isocyanate to afford [(Tbf)Y{κ2-(N,O)-Me3SiN(Me3SiCH2)CO}2(THF)] (6) but it does not react with alkenes. Treating 1 with [Ph3C]+[B(C6F5)4]− in bromobenzene generates a moderately active ethylene polymerization catalyst (36 kg mol−1 h−1 bar−1).


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