Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir Prelog Weg 1-5, 8093, Zürich, Switzerland.
Department of Chemistry, University of California, Berkeley, CA, 94720-1460, USA.
Angew Chem Int Ed Engl. 2018 Mar 19;57(13):3431-3434. doi: 10.1002/anie.201800542. Epub 2018 Feb 21.
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 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.
尽管具有工业相关性，但设计无需助催化剂即可生成亲电金属烷基物种的高效负载型乙烯聚合催化剂仍然是一项挑战。本文描述了具有通式[(≡SiO)LnCp*]的结构明确的硅石负载茂钇和茂钐配合物的合成和特性。这些结构明确的表面物种在没有添加助催化剂的情况下对乙烯聚合具有很高的活性。引发过程据推测是通过单电子转移来实现的。
