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1H-, 13C-NMR and Ethylene Polymerization Studies of Zirconocene/MAO Catalysts: Effect of the Ligand Structure on the Formation of Active Intermediates and Polymerization Kinetics Full article

Journal Journal of Organometallic Chemistry
ISSN: 0022-328X
Output data Year: 2003, Volume: 683, Number: 1, Pages: 92-102 Pages count : 11 DOI: 10.1016/S0022-328X(03)00443-1
Tags 1H- and 13C-NMR, Metallocene catalysts, Polyethylene, Structure-property relations, Transition metal chemistry
Authors Bryliakov Konstantin P. 1,2 , Semikolenova Nina V. 1 , Yudaev Dmitrii V. 1 , Zakharov Vladimir A. 1 , Brintzinger Hans H. 3 , Ystenes Martin 4 , Rytter Erling 4,5 , Talsi Evgenii P. 1,2
Affiliations
1 Boreskov Institute of Catalysis, Prospect Akad. Lavrentieva, 5, Novosibirsk 630090, Russia
2 Natural Sciences Department, Novosibirsk State University, Novosibirsk 630090, Russia
3 Fachbereich Chemie, University of Konstanz, D-78457 Konstanz, Germany
4 Department of Chemical Engineering, Norwegian University of Science and Technology (NTNU), N-7491 Trondheim, Norway
5 Statoil Research Centre, N-7005 Trondheim, Norway

Funding (2)

1 Norwegian University of Science and Technology
2 International Association for the Promotion of Co-operation with Scientists from the New Independent States of the Former Soviet Union 00-00841

Abstract: Using 1H- and 13C-NMR spectroscopies, cationic intermediates formed by activation of L2ZrCl2 with methylaluminoxane (MAO) in toluene were monitored at Al/Zr ratios from 50 to 1000 (L2 are various cyclopentadienyl (Cp), indenyl (Ind) and fluorenyl (Flu) ligands). The following catalysts were studied: (Cp-R)2ZrCl2 (R=Me, 1,2-Me2, 1,2,3-Me3, 1,2,4-Me3, Me4, Me5, n-Bu, t-Bu), rac-ethanediyl(Ind)2ZrCl2, rac-Me2Si(Ind)2ZrCl2, rac-Me2Si(1-Ind-2-Me)2ZrCl2, rac-ethanediyl(1-Ind-4,5,6,7-H4)2ZrCl2, (Ind-2-Me)2ZrCl2, Me2C(Cp)(Flu)ZrCl2, Me2C(Cp-3-Me)(Flu)ZrCl2 and Me2Si(Flu)2ZrCl2. Correlations between spectroscopic and ethene polymerization data for catalysts (Cp-R)2ZrCl2/MAO (R=H, Me, 1,2-Me2, 1,2,3-Me3, 1,2,4-Me3, Me4, Me5, n-Bu, t-Bu) and rac-Me2Si(Ind)2ZrCl2 were established. The catalysts (Cp-R)2ZrCl2/AlMe3/CPh3+B(C6F5)4− (R=Me, 1,2-Me2, 1,2,3-Me3, 1,2,4-Me3, Me4, n-Bu, t-Bu) were also studied for comparison of spectroscopic and polymerization data with MAO-based systems. Complexes of type (Cp-R)2ZrMe+←Me−-Al≡MAO (IV) with different [Me-MAO]− counteranions have been identified in the (Cp-R)2ZrCl2/MAO (R=n-Bu, t-Bu) systems at low Al/Zr ratios (50–200). At Al/Zr ratios of 500–1000, the complex [L2Zr(μ-Me)2AlMe2]+[Me-MAO]− (III) dominates in all MAO-based reaction systems studied. Ethene polymerization activity strongly depends on the Al/Zr ratio (Al/Zr=200–1000) for the systems (Cp-R)2ZrCl2/MAO (R=H, Me, n-Bu, t-Bu), while it is virtually constant in the same range of Al/Zr ratios for the catalytic systems (Cp-R)2ZrCl2/MAO (R=1,2-Me2, 1,2,3-Me3, 1,2,4-Me3, Me4) and rac-Me2Si(Ind)2ZrCl2/MAO. The data obtained are interpreted on assumption that complex III is the main precursor of the active centers of polymerization in MAO-based systems.
Cite: Bryliakov K.P. , Semikolenova N.V. , Yudaev D.V. , Zakharov V.A. , Brintzinger H.H. , Ystenes M. , Rytter E. , Talsi E.P.
1H-, 13C-NMR and Ethylene Polymerization Studies of Zirconocene/MAO Catalysts: Effect of the Ligand Structure on the Formation of Active Intermediates and Polymerization Kinetics
Journal of Organometallic Chemistry. 2003. V.683. N1. P.92-102. DOI: 10.1016/S0022-328X(03)00443-1 WOS Scopus РИНЦ ANCAN OpenAlex
Files: Full text from publisher
Dates:
Submitted: Mar 31, 2003
Accepted: May 12, 2003
Published online: Sep 26, 2003
Published print: Oct 7, 2003
Identifiers:
Web of science: WOS:000185957300013
Scopus: 2-s2.0-0141605192
Elibrary: 13438844
Chemical Abstracts: 2003:772751
Chemical Abstracts (print): 140:42511
OpenAlex: W2143840603
Citing:
DB Citing
Web of science 56
Scopus 61
Elibrary 61
OpenAlex 53
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