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Secondary metathesis with Grubbs catalysts in the 1,4-polybutadiene system

Paper ID Volume ID Publish Year Pages File Format Full-Text
52100 46865 2008 6 PDF Available
Title
Secondary metathesis with Grubbs catalysts in the 1,4-polybutadiene system
Abstract

The Grubbs catalysts show low cis:trans selectivity in the primary metathesis of 1,5-cyclooctadiene (COD). However, secondary metathesis of 1,4-polybutadiene, which is a much slower reaction, transforms the mixture into thermodynamical equilibrium with considerable formation of trans,trans,trans-1,5,9-cyclododecatriene (CDT). Only the NHC (N-heterocyclic carbene) substituted catalysts were found to be efficient in the polymerization of trans,trans,trans-1,5,9-cyclododecatriene to obtain 1,4-polybutadiene. For the polymerization of cyclooctene (CO), NHC based catalysts show an initial higher trans content, while the phosphine catalysts show more cis content. This initial cis:trans ratio is a fingerprint of the active species and can be used to determine mechanistic pathways.

Keywords
Metathesis; Ruthenium; Cyclooctadiene; Cyclododecatriene; 1,4-polybutadiene; Depolymerization
First Page Preview
Secondary metathesis with Grubbs catalysts in the 1,4-polybutadiene system
Publisher
Database: Elsevier - ScienceDirect
Journal: Catalysis Communications - Volume 9, Issue 6, 31 March 2008, Pages 1054–1059
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Catalysis