Premium
Bifunctional cobalt Salen complex: a highly selective catalyst for the coupling of CO 2 and epoxides under mild conditions
Author(s) -
Li Hongchun,
Niu Yongsheng
Publication year - 2011
Publication title -
applied organometallic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.53
H-Index - 71
eISSN - 1099-0739
pISSN - 0268-2605
DOI - 10.1002/aoc.1781
Subject(s) - chemistry , cyclohexene oxide , bifunctional , lewis acids and bases , polymer chemistry , propylene oxide , cobalt , catalysis , cyclohexene , epoxide , ligand (biochemistry) , propylene carbonate , ether , polycarbonate , selectivity , thermal stability , ketone , carbonate , copolymer , organic chemistry , polymer , biochemistry , receptor , ethylene oxide , electrode , electrochemistry
A bifunctional cobalt Salen complex containing a Lewis acid metal center and two covalent bonded Lewis bases on the ligand was designed and used for the coupling of CO 2 and epoxides under mild conditions. The complex exhibited excellent activity (turnover frequency = 673/h) and selectivity (no less than 97%) for polymer formation in the copolymerization of propylene oxide (PO) and CO 2 at an appropriate combination of all variables. High molecular weight of 110 200 and yield 99% were achieved at a higher [PO]/[complex] ratio of 6000:1. The complex also worked satisfactorily for the terpolymerization of CO 2 , PO and cyclohexene oxide (CHO), without formation of cyclic carbonate or ether linkages to give the polycarbonate. High cyclohexene carbonate unit content in the CO 2 /PO/CHO terpolymers resulted in enhanced thermal stability. Copyright © 2011 John Wiley & Sons, Ltd.