Bimetallic catalysis for styrene homopolymerization and ethylene-styrene copolymerization. Exceptional comonomer selectivity and insertion regiochemistry

Neng Guo, Liting Li, Tobin J Marks

Research output: Contribution to journalArticle

141 Citations (Scopus)

Abstract

This communication reports the styrene homopolymerization behavior and ethylene-styrene copolymerization behavior of the covalently linked bimetallic constrained geometry catalyst (μ-CH2CH2-3,3′){(η5-indenyl)[1-Me2Si(tBuN)](TiMe2)}2 (Ti2), which is the first single-site catalyst that effects not only styrene homopolymerization with high activity, but also efficient ethylene-styrene copolymerization over a broad styrene composition range (0-76% at 20 °C, 1.0 atm ethylene pressure). In styrene homopolymerization, a 50× increase in polymerization activity is achieved with Ti2 vs the mononuclear analogue, Ti1, using an identical trityl borate cocatalyst and polymerization conditions. In ethylene + styrene copolymerization, Ti2 enchains ∼20% more styrene than Ti1 under identical reaction conditions. 13C NMR spectroscopy indicates that greater than two consecutive styrene units are enchained in the copolymer backbone produced by Ti2 + Ph3C+B(C6F5)4-. End group analysis of the styrene homopolymer produced by Ti2 + Ph3C+B(C6F5)4- suggests that 1,2-regiochemistry is installed in ∼50% of the initiation steps. This unusual microstructure is believed to be related to the bimetallic catalyst structure.

Original languageEnglish
Pages (from-to)6542-6543
Number of pages2
JournalJournal of the American Chemical Society
Volume126
Issue number21
DOIs
Publication statusPublished - Jun 2 2004

Fingerprint

Styrene
Homopolymerization
Catalysis
Copolymerization
Ethylene
Polymerization
Catalysts
ethylene
Borates
Nuclear magnetic resonance spectroscopy
Magnetic Resonance Spectroscopy
Copolymers
Pressure
Microstructure

ASJC Scopus subject areas

  • Chemistry(all)

Cite this

@article{f9fb0ffff11742a39187ae2b93a8fe3d,
title = "Bimetallic catalysis for styrene homopolymerization and ethylene-styrene copolymerization. Exceptional comonomer selectivity and insertion regiochemistry",
abstract = "This communication reports the styrene homopolymerization behavior and ethylene-styrene copolymerization behavior of the covalently linked bimetallic constrained geometry catalyst (μ-CH2CH2-3,3′){(η5-indenyl)[1-Me2Si(tBuN)](TiMe2)}2 (Ti2), which is the first single-site catalyst that effects not only styrene homopolymerization with high activity, but also efficient ethylene-styrene copolymerization over a broad styrene composition range (0-76{\%} at 20 °C, 1.0 atm ethylene pressure). In styrene homopolymerization, a 50× increase in polymerization activity is achieved with Ti2 vs the mononuclear analogue, Ti1, using an identical trityl borate cocatalyst and polymerization conditions. In ethylene + styrene copolymerization, Ti2 enchains ∼20{\%} more styrene than Ti1 under identical reaction conditions. 13C NMR spectroscopy indicates that greater than two consecutive styrene units are enchained in the copolymer backbone produced by Ti2 + Ph3C+B(C6F5)4-. End group analysis of the styrene homopolymer produced by Ti2 + Ph3C+B(C6F5)4- suggests that 1,2-regiochemistry is installed in ∼50{\%} of the initiation steps. This unusual microstructure is believed to be related to the bimetallic catalyst structure.",
author = "Neng Guo and Liting Li and Marks, {Tobin J}",
year = "2004",
month = "6",
day = "2",
doi = "10.1021/ja048761f",
language = "English",
volume = "126",
pages = "6542--6543",
journal = "Journal of the American Chemical Society",
issn = "0002-7863",
publisher = "American Chemical Society",
number = "21",

}

TY - JOUR

T1 - Bimetallic catalysis for styrene homopolymerization and ethylene-styrene copolymerization. Exceptional comonomer selectivity and insertion regiochemistry

AU - Guo, Neng

AU - Li, Liting

AU - Marks, Tobin J

PY - 2004/6/2

Y1 - 2004/6/2

N2 - This communication reports the styrene homopolymerization behavior and ethylene-styrene copolymerization behavior of the covalently linked bimetallic constrained geometry catalyst (μ-CH2CH2-3,3′){(η5-indenyl)[1-Me2Si(tBuN)](TiMe2)}2 (Ti2), which is the first single-site catalyst that effects not only styrene homopolymerization with high activity, but also efficient ethylene-styrene copolymerization over a broad styrene composition range (0-76% at 20 °C, 1.0 atm ethylene pressure). In styrene homopolymerization, a 50× increase in polymerization activity is achieved with Ti2 vs the mononuclear analogue, Ti1, using an identical trityl borate cocatalyst and polymerization conditions. In ethylene + styrene copolymerization, Ti2 enchains ∼20% more styrene than Ti1 under identical reaction conditions. 13C NMR spectroscopy indicates that greater than two consecutive styrene units are enchained in the copolymer backbone produced by Ti2 + Ph3C+B(C6F5)4-. End group analysis of the styrene homopolymer produced by Ti2 + Ph3C+B(C6F5)4- suggests that 1,2-regiochemistry is installed in ∼50% of the initiation steps. This unusual microstructure is believed to be related to the bimetallic catalyst structure.

AB - This communication reports the styrene homopolymerization behavior and ethylene-styrene copolymerization behavior of the covalently linked bimetallic constrained geometry catalyst (μ-CH2CH2-3,3′){(η5-indenyl)[1-Me2Si(tBuN)](TiMe2)}2 (Ti2), which is the first single-site catalyst that effects not only styrene homopolymerization with high activity, but also efficient ethylene-styrene copolymerization over a broad styrene composition range (0-76% at 20 °C, 1.0 atm ethylene pressure). In styrene homopolymerization, a 50× increase in polymerization activity is achieved with Ti2 vs the mononuclear analogue, Ti1, using an identical trityl borate cocatalyst and polymerization conditions. In ethylene + styrene copolymerization, Ti2 enchains ∼20% more styrene than Ti1 under identical reaction conditions. 13C NMR spectroscopy indicates that greater than two consecutive styrene units are enchained in the copolymer backbone produced by Ti2 + Ph3C+B(C6F5)4-. End group analysis of the styrene homopolymer produced by Ti2 + Ph3C+B(C6F5)4- suggests that 1,2-regiochemistry is installed in ∼50% of the initiation steps. This unusual microstructure is believed to be related to the bimetallic catalyst structure.

UR - http://www.scopus.com/inward/record.url?scp=2542612839&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=2542612839&partnerID=8YFLogxK

U2 - 10.1021/ja048761f

DO - 10.1021/ja048761f

M3 - Article

C2 - 15161268

AN - SCOPUS:2542612839

VL - 126

SP - 6542

EP - 6543

JO - Journal of the American Chemical Society

JF - Journal of the American Chemical Society

SN - 0002-7863

IS - 21

ER -