Silica-Supported Pentamethylcyclopentadienyl Ytterbium(II) and Samarium(II) Sites: Ultrahigh Molecular Weight Polyethylene without Co-Catalyst

Florian Allouche; Ka Wing Chan; Alexey Fedorov; Richard A Andersen; Christophe Copéret

doi:10.1002/anie.201800542

Silica-Supported Pentamethylcyclopentadienyl Ytterbium(II) and Samarium(II) Sites: Ultrahigh Molecular Weight Polyethylene without Co-Catalyst

Angew Chem Int Ed Engl. 2018 Mar 19;57(13):3431-3434. doi: 10.1002/anie.201800542. Epub 2018 Feb 21.

Authors

Florian Allouche¹, Ka Wing Chan¹, Alexey Fedorov¹, Richard A Andersen², Christophe Copéret¹

Affiliations

¹ Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir Prelog Weg 1-5, 8093, Zürich, Switzerland.
² Department of Chemistry, University of California, Berkeley, CA, 94720-1460, USA.

PMID: 29377403
DOI: 10.1002/anie.201800542

Abstract

Designing highly active supported ethylene polymerization catalysts that do not require a co-catalyst to generate electrophilic metal alkyl species is still a challenge despite its industrial relevance. Described herein is the synthesis and characterization of well-defined silica-supported cyclopentadienyl Ln^II sites (Ln=Yb and Sm) of general formula [(≡SiO)LnCp*]. These well-defined surface species are highly activite towards ethylene polymerization in the absence of added co-catalyst. Initiation is proposed to occur by single electron transfer.

Keywords: catalysis; electron transfer; ethylene polymerization; lanthanocenes; surface chemistry.

Publication types

Research Support, Non-U.S. Gov't