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Chain Transfer to Toluene in Styrene Coordination Polymerization
Author(s) -
Lin Fei,
Liu Zhaohe,
Wang Meiyan,
Liu Bo,
Li Shihui,
Cui Dongmei
Publication year - 2020
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.201914603
Subject(s) - chain transfer , styrene , polymerization , toluene , chemistry , polymer chemistry , catalysis , atom transfer radical polymerization , living polymerization , fluorine , alkyl , photochemistry , radical polymerization , organic chemistry , polymer , copolymer
The chain‐transfer reaction is rather important in coordination polymerization regarding catalytic efficiency, adjustment of molecular weight, and control of chain structure. To date, chain transfer to H 2 and Al, Mg, and Zn alkyl compounds and β‐H elimination are the commonly encountered modes. Now a novel chain transfer to toluene is reported. By introducing fluorine atoms into the β‐diketimine ligands, an inert catalytic system for styrene (St) coordination polymerization was transferred into the highly active one. The activity increased with an increase in the number of fluorines in the ligands. Surprisingly, the molecular weights of resultant polystyrenes are very low ( M n =2000–6600 Da) despite of St loadings, corresponding up to 121 chains per active species. The mechanisms were investigated by DFT simulation, MALDI‐TOF MS, isotope tracing experiment and 2D NMR spectrum analyses, which revealed that the fluorine activated the polymerization and directed chain transfer to toluene.