Reversible coordinative chain transfer polymerization of styrene by rare earth borohydrides,chlorides/dialkylmagnesium systems |
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| Authors: | Philippe Zinck Andreia Valente Fanny Bonnet Ana Violante André Mortreux Marc Visseaux Simona Ilinca Rob Duchateau Pascal Roussel |
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| Institution: | 1. Email:philippe.zinck@ensc‐ lille.fr;4. Université Lille Nord de France—ENSCL, Unité de Catalyse et Chimie du Solide, UMR CNRS 8181, Equipe Synthèses Organométalliques et Catalyse, Cité Scientifique, 59652 Villeneuve d'Ascq, France;5. Department of Chemical Engineering and Chemistry, Laboratory of Polymer Chemistry, Eindhoven University of Technology, Den Dolech 2, 5600 MB Eindhoven, The Netherlands |
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| Abstract: | The ability of various rare earth borohydride and chloride complexes/n‐butylethylmagnesium systems to operate styrene chain transfer polymerization in mild conditions has been assessed. Thirteen precatalysts have been considered: the rare earth trisborohydrides Ln(BH4)3(THF)x (x = 3, Ln = Nd (1), La (2), Sm (3), x = 2, Ln = Y (4), Sc (5)), the rare earth chlorides LnCl3(THF)x (x = 3, Ln = Nd (6), La (7), Sm (8), Y (9), x = 2, Ln = Sc (10)), the mixed La(BH4)2Cl(THF)2.6 (11) and the half‐lanthanidocenes Cp*Ln(BH4)2(THF)2 (Ln = Nd (12), La (13)). Six systems were found to be active precatalysts for the polymerization of styrene. 1 , 2 , and 11 led to an efficient transmetalation of the growing polystyrene chain with the simultaneous occurrence of βH elimination, whereas 7 , 12 , and 13 led to catalyzed chain growth behavior. It is noteworthy that the catalyzed chain growth obtained with 12 and 13 occurs with significant stereoselectivity. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 802–814, 2010 |
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| Keywords: | Aufbau reaktion β hydrogen elimination half‐sandwich complexes polystyrene transmetalation |
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