Propylene Polymerization with Bis(phenoxy-imine) Group-4 Catalysts Using iBu3Al/Ph3CB(C6F5)4 as a Cocatalyst

2002 ◽  
Vol 23 (18) ◽  
pp. 1118-1123 ◽  
Author(s):  
Junji Saito ◽  
Mitsuhiko Onda ◽  
Shigekazu Matsui ◽  
Makoto Mitani ◽  
Rieko Furuyama ◽  
...  
Keyword(s):  
Propylene Polymerization ◽  
Imine Group ◽  
Group 4

Stereoselective and regioselective propylene polymerization with group 4 bisphenolate ether complexes

2012 ◽  
Vol 50 (13) ◽  
pp. 2604-2611 ◽  
Author(s):  
Sören Randoll ◽  
Elizabeth T. Kiesewetter ◽  
Robert M. Waymouth
Keyword(s):  
Propylene Polymerization ◽  
Group 4

Selectivity in Propylene Polymerization with Group 4 Cp−Amido Catalysts

1997 ◽  
Vol 16 (13) ◽  
pp. 2879-2885 ◽  
Author(s):  
Andrew L. McKnight ◽  
Md. Athar Masood ◽  
Robert M. Waymouth ◽  
Daniel A. Straus
Keyword(s):  
Propylene Polymerization ◽  
Group 4

scholarly journals Propylene Polymerization and Deactivation Processes with Isoselective {Cp/Flu} Zirconocene Catalysts

Catalysts ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 959
Author(s):  
Xavier Desert ◽  
Thierry Roisnel ◽  
Vincent Dorcet ◽  
Katty Den Dauw ◽  
Aurélien Vantomme ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Dft Calculations ◽  
Isotactic Polypropylene ◽  
13C Nmr ◽  
13C Nmr Spectroscopy ◽  
Propylene Polymerization ◽  
Activation Process ◽  
Dormant State ◽  
Group 4 ◽  
New Compounds

Industrially relevant single-site precatalysts used to produce isotactic polypropylene (iPP) include C2-symmetric {SBI} and C1-symmetric {Cp/Flu} complexes of group 4 metals. While the latter can produce iPPs with a higher degree of isotacticity, they also suffer from poor productivity compared to their {SBI} counterparts. Several causes for this trend have been suggested—2,1-Regioinsertions are frequently pointed out, as they are suspected to drive the catalyst into a dormant state. While this event does not seem to significantly impact the productivity of {SBI} systems, the influence of these regioerror is poorly documented for isoselective {Cp/Flu} precatalysts. To address this issue, new Ph2X(Cp)(Flu) (Ph2X = Ph2C, FluC, Ph2Si) proligands (2a–k) and some of the corresponding dichlorozirconocenes (3a–h,k) were synthesized. These new compounds were characterized and tested in homogeneous propylene polymerization at 60 °C and the amounts of regioerrors in the resulting polymers were examined by 13C NMR spectroscopy. A possible correlation between poor productivity and a high number of regioerrors was investigated and is discussed. Furthermore, a C-H activation process in the bulky nBu3C substituent upon activation of 4c (the dimethylated analog of 3c) by B(C6F5)3 has been evidenced by NMR; DFT calculations support this C-H activation as a deactivation mechanism.

Isospecific propylene polymerization with unbridged Group 4 metallocenes

1993 ◽  
Vol 115 (16) ◽  
pp. 7529-7530 ◽  
Author(s):  
Abbas Razavi ◽  
Jerry L. Atwood
Keyword(s):  
Propylene Polymerization ◽  
Group 4

Chiral-at-ansa-Bridged Group 4 Metallocene Complexes {(R1R2C)-(3,6-tBu2Flu)(3-R3-5-Me-C5H2)}MCl2: Synthesis, Structure, Stereochemistry, and Use in Highly Isoselective Propylene Polymerization

2011 ◽  
Vol 30 (2) ◽  
pp. 263-272 ◽  
Author(s):  
Evgeny Kirillov ◽  
Nicolas Marquet ◽  
Manuela Bader ◽  
Abbas Razavi ◽  
Vincenzo Belia ◽  
...  
Keyword(s):  
Propylene Polymerization ◽  
Group 4 ◽  
Metallocene Complexes
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