3D-QSAR as a Tool for Understanding and Improving Single-Site Polymerization Catalysts. A Review

2014 ◽  
Vol 33 (12) ◽  
pp. 2944-2959 ◽  
Author(s):  
Victor L. Cruz ◽  
Sonia Martinez ◽  
Javier Ramos ◽  
Javier Martinez-Salazar
Keyword(s):  
3D Qsar ◽  
Single Site ◽  
Polymerization Catalysts

ChemInform Abstract: 3D-QSAR as a Tool for Understanding and Improving Single-Site Polymerization Catalysts. A Review

ChemInform ◽  
2014 ◽  
Vol 45 (33) ◽  
pp. no-no
Author(s):  
Victor L. Cruz ◽  
Sonia Martinez ◽  
Javier Ramos ◽  
Javier Martinez-Salazar
Keyword(s):  
3D Qsar ◽  
Single Site ◽  
Polymerization Catalysts

Well-Defined Silica-Supported Zirconium-Benzyl Cationic Species: Improved Heterogenization of Single-Site Polymerization Catalysts

2014 ◽  
Vol 2014 (5) ◽  
pp. 888-895 ◽  
Author(s):  
Nicolas Popoff ◽  
Benoît Macqueron ◽  
Wissam Sayhoun ◽  
Jeff Espinas ◽  
Jérémie Pelletier ◽  
...  
Keyword(s):  
Single Site ◽  
Polymerization Catalysts ◽  
Cationic Species

Block copolymer micelles as nanoreactors for single-site polymerization catalysts

2008 ◽  
Vol 47 (1) ◽  
pp. 197-209 ◽  
Author(s):  
Cécile Bouilhac ◽  
Eric Cloutet ◽  
Daniel Taton ◽  
Alain Deffieux ◽  
Redouane Borsali ◽  
...  
Keyword(s):  
Block Copolymer ◽  
Single Site ◽  
Polymerization Catalysts ◽  
Block Copolymer Micelles ◽  
Copolymer Micelles

Ethylene and 1-hexene polymerization using zirconium iminophosphonamide complexes

2006 ◽  
Vol 84 (2) ◽  
pp. 214-224 ◽  
Author(s):  
Robert Tomaszewski ◽  
Rainer Vollmerhaus ◽  
Abdulaziz Al-Humydi ◽  
Qinyan Wang ◽  
Nicholas J Taylor ◽  
...  
Keyword(s):  
Ethylene Polymerization ◽  
Room Temperature ◽  
Chain Transfer ◽  
Single Site ◽  
Complex Behavior ◽  
Polymerization Catalysts ◽  
Dichloromethane Solution ◽  
Polymerization Catalysis ◽  
Multinuclear Nmr Spectroscopy ◽  
Poly Ethylene

Ethylene polymerization was studied using a variety of iminophosphonamide (PN2) complexes of zirconium. Bis(PN2) dichloride complexes [Ph2P(NR′)2]2ZrX2 (X = Cl; 1a: R′ = p-tolyl; 1b: R′ = Bn; 1c: R′ = C6F5) or dimethyl complexes (X = Me; 2a: R′ = p-tolyl; 2b: R′ = Bn) and cyclopentadienyl(PN2)zirconium dichloride complexes [η5-C5R′′5][R2P(NR′)2]ZrCl2 (3a: R′ = p-tolyl, R = Ph, R′′ = H; 3b: R′ = SiMe3, R = Et, R′′ = H; 3c: R′ = C6F5, R = Ph, R′′ = H; 3e: R′ = 3,5-(CF3)2Ph, R = Ph, R′′ = H; 3f: R′ = 3,5-(CF3)2Ph, R = Ph, R′′ = Me) or dimethyl analogs [η5-C5H5][R2P(NR′)2]ZrMe2 (4a: R′ = p-tolyl, R = Ph; 4b: R′ = SiMe3, R = Et) were evaluated under a range of conditions using methylaluminoxane (PMAO) activator. Complexes 1 and 2 behave as precursors to single-site polymerization catalysts under the conditions studied, while complexes 3 or dialkyls 4 show more complex behavior and formation of poly(ethylene) with a bimodal molecular weight distribution. In contrast, activation of dialkyl complexes 4 with [Ph3C][B(C6F5)4] and polymerization in the presence of small amounts of PMAO or TIBAL as scavenger, led to single-site behavior. PMAO reacts with the neutral dialkyls via ligand abstraction to produce a number of P-containing species that may explain the multi-site behavior observed when using this activator. Dialkyls 4 react cleanly with [Ph3C][B(C6F5)4] in haloarene or even dichloromethane solution to furnish the corresponding cationic alkyls 5, which were characterized by multinuclear NMR spectroscopy. Fluxional dinuclear species are formed in the presence of excess dialkyl and these are susceptible to C—H activation to form µ-Me,µ-CH2 complexes one of which could be isolated in pure form. The cationic alkyls initiate the polymerization of 1-hexene at room temperature in chlorobenzene solution, but extensive chain transfer occurs and the systems are not living.Key words: single site, early metal olefin polymerization catalysis.

Redox Control within Single-Site Polymerization Catalysts

2006 ◽  
Vol 128 (23) ◽  
pp. 7410-7411 ◽  
Author(s):  
Charlotte K. A. Gregson ◽  
Vernon C. Gibson ◽  
Nicholas J. Long ◽  
Edward L. Marshall ◽  
Phillip J. Oxford ◽  
...  
Keyword(s):  
Single Site ◽  
Redox Control ◽  
Polymerization Catalysts

“Bound but Not Gagged”Immobilizing Single-Site α-Olefin Polymerization Catalysts

2005 ◽  
Vol 105 (11) ◽  
pp. 4073-4147 ◽  
Author(s):  
John R. Severn ◽  
John C. Chadwick ◽  
Robbert Duchateau ◽  
Nic Friederichs
Keyword(s):  
Olefin Polymerization ◽  
Single Site ◽  
Polymerization Catalysts
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