Olefin polymerization on Cr(III)/SiO<inf>2</inf>: Mechanistic insights from the differences in reactivity between ethene and propene

Murielle F. Delley, C. S. Praveen, András P. Borosy, Francisco Núñez-Zarur, Aleix Comas-Vives, Christophe Copéret

Resultado de la investigación: Contribución a una revistaArtículoInvestigaciónrevisión exhaustiva

11 Citas (Scopus)

Resumen

© 2017 Elsevier Inc. Silica-supported well-defined Cr(III) sites, which polymerize ethene, are barely reactive towards propene while they copolymerize propene and ethene, a reactivity pattern similar to what is observed for the Phillips catalyst. In contrast to ethene, propene is only polymerized in low amounts and by a small fraction of sites, while during propene/ethene copolymerization small amounts of olefinic oligomers are formed. This difference of reactivity pattern among various olefins is further examined by DFT calculations using periodic amorphous models, focusing on the initiation of polymerization by olefin insertion into the Cr–O bond vs. the heterolytic C–H activation of the alkene. For both mechanisms, we found that the initial activation displays similar energetics for propene and ethene, while the subsequent propene insertion associated with chain growth becomes rather demanding, which rationalizes the observed difference of reactivity between ethene and propene.
Idioma originalInglés estadounidense
Páginas (desde-hasta)223-230
Número de páginas8
PublicaciónJournal of Catalysis
DOI
EstadoPublicada - 1 ene 2017

Huella dactilar

Alkenes
alkenes
Olefins
Propylene
polymerization
reactivity
Polymerization
insertion
activation
copolymerization
oligomers
methylidyne
silicon dioxide
catalysts
Chemical activation
ethylene
propylene
Oligomers
Discrete Fourier transforms
Silicon Dioxide

Citar esto

Delley, Murielle F. ; Praveen, C. S. ; Borosy, András P. ; Núñez-Zarur, Francisco ; Comas-Vives, Aleix ; Copéret, Christophe. / Olefin polymerization on Cr(III)/SiO<inf>2</inf>: Mechanistic insights from the differences in reactivity between ethene and propene. En: Journal of Catalysis. 2017 ; pp. 223-230.
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title = "Olefin polymerization on Cr(III)/SiO2: Mechanistic insights from the differences in reactivity between ethene and propene",
abstract = "{\circledC} 2017 Elsevier Inc. Silica-supported well-defined Cr(III) sites, which polymerize ethene, are barely reactive towards propene while they copolymerize propene and ethene, a reactivity pattern similar to what is observed for the Phillips catalyst. In contrast to ethene, propene is only polymerized in low amounts and by a small fraction of sites, while during propene/ethene copolymerization small amounts of olefinic oligomers are formed. This difference of reactivity pattern among various olefins is further examined by DFT calculations using periodic amorphous models, focusing on the initiation of polymerization by olefin insertion into the Cr–O bond vs. the heterolytic C–H activation of the alkene. For both mechanisms, we found that the initial activation displays similar energetics for propene and ethene, while the subsequent propene insertion associated with chain growth becomes rather demanding, which rationalizes the observed difference of reactivity between ethene and propene.",
author = "Delley, {Murielle F.} and Praveen, {C. S.} and Borosy, {Andr{\'a}s P.} and Francisco N{\'u}{\~n}ez-Zarur and Aleix Comas-Vives and Christophe Cop{\'e}ret",
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Olefin polymerization on Cr(III)/SiO<inf>2</inf>: Mechanistic insights from the differences in reactivity between ethene and propene. / Delley, Murielle F.; Praveen, C. S.; Borosy, András P.; Núñez-Zarur, Francisco; Comas-Vives, Aleix; Copéret, Christophe.

En: Journal of Catalysis, 01.01.2017, p. 223-230.

Resultado de la investigación: Contribución a una revistaArtículoInvestigaciónrevisión exhaustiva

TY - JOUR

T1 - Olefin polymerization on Cr(III)/SiO2: Mechanistic insights from the differences in reactivity between ethene and propene

AU - Delley, Murielle F.

AU - Praveen, C. S.

AU - Borosy, András P.

AU - Núñez-Zarur, Francisco

AU - Comas-Vives, Aleix

AU - Copéret, Christophe

PY - 2017/1/1

Y1 - 2017/1/1

N2 - © 2017 Elsevier Inc. Silica-supported well-defined Cr(III) sites, which polymerize ethene, are barely reactive towards propene while they copolymerize propene and ethene, a reactivity pattern similar to what is observed for the Phillips catalyst. In contrast to ethene, propene is only polymerized in low amounts and by a small fraction of sites, while during propene/ethene copolymerization small amounts of olefinic oligomers are formed. This difference of reactivity pattern among various olefins is further examined by DFT calculations using periodic amorphous models, focusing on the initiation of polymerization by olefin insertion into the Cr–O bond vs. the heterolytic C–H activation of the alkene. For both mechanisms, we found that the initial activation displays similar energetics for propene and ethene, while the subsequent propene insertion associated with chain growth becomes rather demanding, which rationalizes the observed difference of reactivity between ethene and propene.

AB - © 2017 Elsevier Inc. Silica-supported well-defined Cr(III) sites, which polymerize ethene, are barely reactive towards propene while they copolymerize propene and ethene, a reactivity pattern similar to what is observed for the Phillips catalyst. In contrast to ethene, propene is only polymerized in low amounts and by a small fraction of sites, while during propene/ethene copolymerization small amounts of olefinic oligomers are formed. This difference of reactivity pattern among various olefins is further examined by DFT calculations using periodic amorphous models, focusing on the initiation of polymerization by olefin insertion into the Cr–O bond vs. the heterolytic C–H activation of the alkene. For both mechanisms, we found that the initial activation displays similar energetics for propene and ethene, while the subsequent propene insertion associated with chain growth becomes rather demanding, which rationalizes the observed difference of reactivity between ethene and propene.

U2 - 10.1016/j.jcat.2017.08.016

DO - 10.1016/j.jcat.2017.08.016

M3 - Article

SP - 223

EP - 230

JO - Journal of Catalysis

JF - Journal of Catalysis

SN - 0021-9517

ER -