Copolymerization of CO2 and cyclohexene oxide using a lysine-based (salen)Cr(III)Cl catalyst.
A new, natural lysine-based (salen)Cr(III)Cl ((lys-salen)Cr(III)Cl) complex was prepared and its catalytic activity for the copolymerization of CO(2) and cyclohexene oxide (CHO) was described in the presence of PPNCl (PPN(+) = bis(triphenylphosphoranylidene)ammonium) as cocatalyst. The influence of the reaction time, operating temperature and the molar ratio of the catalyst components on the copolymerization was investigated in detail. The results showed that the (lys-salen)Cr(III)Cl, synthesized from non-ortho-diamine, could effectively catalyze the alternating copolymerization (carbonate linkages = 94.6-99.0%). The selectivity was >95%, and was less sensitive to the temperature and the molar ratio of catalyst components, compared to that of the copolymerization catalyzed by traditional salen-metal complexes. The ESI-MS analyses of oligomer and (lys-salen)Cr(III)Cl indicated that a possible chain-transfer reaction had taken place, which might be induced by the water coordinating to the central metal ion.
Guo
Liping
L
Department of Chemistry, Zhejiang University, Hangzhou, 310027, People's Republic of China.
Wang
Congmin
C
Zhao
Wenjia
W
Li
Haoran
H
Sun
Weilin
W
Shen
Zhiquan
Z
D002245:Carbon Dioxide / Q000737:chemistry*; D002384:Catalysis; D053138:Cyclohexenes / Q000737:chemistry*; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization
D053138:Cyclohexenes; D009942:Organometallic Compounds; D011108:Polymers; D002245:Carbon Dioxide; C007193:cyclohexene oxide