Ionic Polymer Microspheres Bearing a Co(III) -Salen Moiety as a Bifunctional Heterogeneous Catalyst for the Efficient Cycloaddition of CO2 and Epoxides.
We report a unique strategy to obtain the bifunctional heterogeneous catalyst TBB-Bpy@Salen-Co (TBB=1,2,4,5-tetrakis(bromomethyl)benzene, Bpy=4,4'-bipyridine, Salen-Co=N,N'-bis({4-dimethylamino}salicylidene)ethylenediamino cobalt(III) acetate) by combining a cross-linked ionic polymer with a Co(III) -salen Schiff base. The catalyst showed extra high activity for CO2 fixation under mild, solvent-free reaction conditions with no requirement for a co-catalyst. The synthesized catalyst possessed distinctive spherical structural features, abundant halogen Br(-) anions with good leaving group ability, and accessible Lewis acidic Co metal centers. These unique features, together with the synergistic role of the Co and Br(-) functional sites, allowed TBB-Bpy@Salen-Co to exhibit enhanced catalytic conversion of CO2 into cyclic carbonates relative to the corresponding monofunctional analogues. This catalyst can be easily recovered and recycled five times without significant leaching of Co or loss of activity. Moreover, based on our experimental results and previous work, a synergistic cycloaddition reaction mechanism was proposed.
The Key Laboratory of Food Colloids and Biotechnology, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi, 214122, P. R. China. lengyan1114@126.com.
Yan
Y
Leng
The Key Laboratory of Food Colloids and Biotechnology, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi, 214122, P. R. China.
Dan
D
Lu
The Key Laboratory of Food Colloids and Biotechnology, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi, 214122, P. R. China.
Chenjun
C
Zhang
The Key Laboratory of Food Colloids and Biotechnology, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi, 214122, P. R. China.
Pingping
P
Jiang
The Key Laboratory of Food Colloids and Biotechnology, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi, 214122, P. R. China.
Weijie
W
Zhang
State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemistry and Chemical Engineering, Nanjing Tech University, Nanjing, 210009, P. R. China.
Jun
J
Wang
D001555:Benzene Derivatives / Q000737:chemistry; D002245:Carbon Dioxide / Q000737:chemistry*; D002384:Catalysis; D003035:Cobalt / Q000737:chemistry*; D061565:Cycloaddition Reaction; D004852:Epoxy Compounds / Q000737:chemistry*; D005029:Ethylenediamines / Q000737:chemistry*; D007477:Ions / Q000737:chemistry; D008863:Microspheres; D009570:Nitriles / Q000737:chemistry; D011108:Polymers / Q000737:chemistry*; D011725:Pyridines / Q000737:chemistry; D012545:Schiff Bases / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared
C408677:1,2,4,5-tetrakis(cyanomethyl)benzene; D001555:Benzene Derivatives; D004852:Epoxy Compounds; D005029:Ethylenediamines; D007477:Ions; D009570:Nitriles; D011108:Polymers; D011725:Pyridines; D012545:Schiff Bases; D002245:Carbon Dioxide; D003035:Cobalt; C011452:disalicylaldehyde ethylenediamine; C034306:4,4'-bipyridyl
CoIII-salen complexes; bifunctional catalysts; carbon dioxide fixation; cycloaddition; ionic polymers