Semi-hydrogenated, asymmetric metallocene catalysts for the propylene polymerization

Martin Schloegl; Carsten Troll; Ulf Thewalt; Bernhard Rieger

doi:10.1515/znb-2003-0608

Semi-hydrogenated, asymmetric metallocene catalysts for the propylene polymerization

Martin Schloegl
, Carsten Troll
, Ulf Thewalt
, Bernhard Rieger

University of Ulm

Research output: Contribution to journal › Article › peer-review

3 Scopus citations

Abstract

The hydrogenation of rac-[1-(9-η⁵-fluorenyl)-2-(5,6-cylopenta-2-methyl-1-η ⁵-indenyl)ethane]metallocene dichlorides (1a: Zr, 1b: Hf) with PtO₂xH₂O/H₂ is reported. The diastereoselective formation of exclusively rac-[1-(2,3,4,5,6,7,8,9-octahydro-η⁵-fluorenyl)-2-(2-methyl- 1,4,4a(R;S),5,6,7,7a(S;R),8-octahydro-s-η⁵-indacenyl)ethane] metallocene dichlorides (2a: Zr, 2b: Hf) was shown by ¹H-NMR and by X-ray analysis of 2a. Both compounds were activated in situ with triisobutylaluminum/PhC₃⁺[B(C₆F ₅)₄]^- and tested as catalysts in propylene polymerization reactions. Comparison to the non-hydrogenated complexes revealed a decrease in molecular weight of the polymer and in catalyst activity. Experiments at elevated temperatures resulted in a lower stereospecificity and reduced isotacticity values indicating a polymerization mechanism analogous to C₂-symmetric catalysts.

Original language	English
Pages (from-to)	533-538
Number of pages	6
Journal	Zeitschrift fur Naturforschung - Section B Journal of Chemical Sciences
Volume	58
Issue number	6
DOIs	https://doi.org/10.1515/znb-2003-0608
State	Published - 1 Jun 2003
Externally published	Yes

Keywords

Diastereoselective Hydrogenation
Metallocene Polymerization Catalyst
Polypropylene

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title = "Semi-hydrogenated, asymmetric metallocene catalysts for the propylene polymerization",

abstract = "The hydrogenation of rac-[1-(9-η5-fluorenyl)-2-(5,6-cylopenta-2-methyl-1-η 5-indenyl)ethane]metallocene dichlorides (1a: Zr, 1b: Hf) with PtO2xH2O/H2 is reported. The diastereoselective formation of exclusively rac-[1-(2,3,4,5,6,7,8,9-octahydro-η5-fluorenyl)-2-(2-methyl- 1,4,4a(R;S),5,6,7,7a(S;R),8-octahydro-s-η5-indacenyl)ethane] metallocene dichlorides (2a: Zr, 2b: Hf) was shown by 1H-NMR and by X-ray analysis of 2a. Both compounds were activated in situ with triisobutylaluminum/PhC3+[B(C6F 5)4]- and tested as catalysts in propylene polymerization reactions. Comparison to the non-hydrogenated complexes revealed a decrease in molecular weight of the polymer and in catalyst activity. Experiments at elevated temperatures resulted in a lower stereospecificity and reduced isotacticity values indicating a polymerization mechanism analogous to C2-symmetric catalysts.",

keywords = "Diastereoselective Hydrogenation, Metallocene Polymerization Catalyst, Polypropylene",

author = "Martin Schloegl and Carsten Troll and Ulf Thewalt and Bernhard Rieger",

note = "Funding Information: The authors thank DFG Deutsche Forschungs-gemeinschaft, SFB 569, for financial support of this research.",

year = "2003",

month = jun,

day = "1",

doi = "10.1515/znb-2003-0608",

language = "English",

volume = "58",

pages = "533--538",

journal = "Zeitschrift fur Naturforschung - Section B Journal of Chemical Sciences",

issn = "0932-0776",

publisher = "Walter de Gruyter GmbH",

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}

TY - JOUR

T1 - Semi-hydrogenated, asymmetric metallocene catalysts for the propylene polymerization

AU - Schloegl, Martin

AU - Troll, Carsten

AU - Thewalt, Ulf

AU - Rieger, Bernhard

N1 - Funding Information: The authors thank DFG Deutsche Forschungs-gemeinschaft, SFB 569, for financial support of this research.

PY - 2003/6/1

Y1 - 2003/6/1

N2 - The hydrogenation of rac-[1-(9-η5-fluorenyl)-2-(5,6-cylopenta-2-methyl-1-η 5-indenyl)ethane]metallocene dichlorides (1a: Zr, 1b: Hf) with PtO2xH2O/H2 is reported. The diastereoselective formation of exclusively rac-[1-(2,3,4,5,6,7,8,9-octahydro-η5-fluorenyl)-2-(2-methyl- 1,4,4a(R;S),5,6,7,7a(S;R),8-octahydro-s-η5-indacenyl)ethane] metallocene dichlorides (2a: Zr, 2b: Hf) was shown by 1H-NMR and by X-ray analysis of 2a. Both compounds were activated in situ with triisobutylaluminum/PhC3+[B(C6F 5)4]- and tested as catalysts in propylene polymerization reactions. Comparison to the non-hydrogenated complexes revealed a decrease in molecular weight of the polymer and in catalyst activity. Experiments at elevated temperatures resulted in a lower stereospecificity and reduced isotacticity values indicating a polymerization mechanism analogous to C2-symmetric catalysts.

AB - The hydrogenation of rac-[1-(9-η5-fluorenyl)-2-(5,6-cylopenta-2-methyl-1-η 5-indenyl)ethane]metallocene dichlorides (1a: Zr, 1b: Hf) with PtO2xH2O/H2 is reported. The diastereoselective formation of exclusively rac-[1-(2,3,4,5,6,7,8,9-octahydro-η5-fluorenyl)-2-(2-methyl- 1,4,4a(R;S),5,6,7,7a(S;R),8-octahydro-s-η5-indacenyl)ethane] metallocene dichlorides (2a: Zr, 2b: Hf) was shown by 1H-NMR and by X-ray analysis of 2a. Both compounds were activated in situ with triisobutylaluminum/PhC3+[B(C6F 5)4]- and tested as catalysts in propylene polymerization reactions. Comparison to the non-hydrogenated complexes revealed a decrease in molecular weight of the polymer and in catalyst activity. Experiments at elevated temperatures resulted in a lower stereospecificity and reduced isotacticity values indicating a polymerization mechanism analogous to C2-symmetric catalysts.

KW - Diastereoselective Hydrogenation

KW - Metallocene Polymerization Catalyst

KW - Polypropylene

UR - https://www.scopus.com/pages/publications/0041743114

U2 - 10.1515/znb-2003-0608

DO - 10.1515/znb-2003-0608

M3 - Article

AN - SCOPUS:0041743114

SN - 0932-0776

VL - 58

SP - 533

EP - 538

JO - Zeitschrift fur Naturforschung - Section B Journal of Chemical Sciences

JF - Zeitschrift fur Naturforschung - Section B Journal of Chemical Sciences

IS - 6

ER -

Semi-hydrogenated, asymmetric metallocene catalysts for the propylene polymerization

Abstract

Keywords

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