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Branching Regulation in Olefin Polymerization via Lewis Acid Triggered Isomerization of Monomers
Author(s) -
Basbug Alhan Hatice E.,
Jones Glen R.,
Harth Eva
Publication year - 2020
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201914742
Subject(s) - isomerization , alkene , branching (polymer chemistry) , chemistry , polymerization , lewis acids and bases , monomer , polymer chemistry , photochemistry , polymer , organic chemistry , catalysis
We present a new strategy to regulate branching in chain‐walking olefin polymerization by triggering a rapid isomerization of 1‐alkene monomers into internal olefins by adding a Lewis acid. Polymerization of internal alkenes proceeds via chain‐walking to give polymers with much higher branching than 1‐alkene analogues. The utility of this approach is exemplified by synthesis of well‐defined block copolymers with distinct branching characteristics per block by addition of Lewis acid midway through a reaction. We propose a novel mechanism whereby Lewis acid undergoes a counterion swap with the complex which favors isomerization as well as forming adducts with ancillary ligands, freeing coordination sites for internal alkene coordination polymerization.