The coupling reaction of carbon dioxide(CO_(2)) and epoxides is one of the most efficient pathways to achieve the carbon balance.However,to accomplish it under the mild conditions,especially under the atmospheric pres...The coupling reaction of carbon dioxide(CO_(2)) and epoxides is one of the most efficient pathways to achieve the carbon balance.However,to accomplish it under the mild conditions,especially under the atmospheric pressure,is still a perplexing problem.Three novel ionic liquids(ILs),[DMAPBrPC][TMGH],[DMAPBrPC][DBUH],and[DMAPBrPC][BTMA],are designed and synthesized.All of them display the excellent catalytic activity for the title reaction achieving the yield over 96.6% under the atmospheric CO_(2) pressure at 60℃.Interestingly,[DMAPBrPC][BTMA]with the inert hydrogen atom in cation exhibits the superior catalytic activity as compared to other two ILs with the protic hydrogen atom in cation along with the same anion.The active hydrogen atom in[DMAPBrPC][TMGH]and[DMAPBrPC][DBUH]would impede the–COO^(-)group to absorb CO 2,which is an unfavorable item for the reaction.Moreover,the strong hydrogen bond in[DMAPBrPC][TMGH]and[DMAPBrPC][DBUH]would lessen the nucleophilic ability of Br^(-) anion resulting in the inferior catalytic performance,which is further confirmed by the density functional theory(DFT)calculations.The cation without the active hydrogen atom could also be employed to design the ILs with the excellent catalytic feature when it is combined with the suitable anion.展开更多
基金This work was supported by the National Natural Science Foundation of China(21975064,22178087)Program of Henan Center for Outstanding Overseas Scientists(GZS2020011)+1 种基金Henan University's First-Class Discipline Science and Technology Research Project(2018YLTD07,2018YLZDYJ11,2019YLZDYJ09)the Excellent Foreign Experts Project of Henan University.
文摘The coupling reaction of carbon dioxide(CO_(2)) and epoxides is one of the most efficient pathways to achieve the carbon balance.However,to accomplish it under the mild conditions,especially under the atmospheric pressure,is still a perplexing problem.Three novel ionic liquids(ILs),[DMAPBrPC][TMGH],[DMAPBrPC][DBUH],and[DMAPBrPC][BTMA],are designed and synthesized.All of them display the excellent catalytic activity for the title reaction achieving the yield over 96.6% under the atmospheric CO_(2) pressure at 60℃.Interestingly,[DMAPBrPC][BTMA]with the inert hydrogen atom in cation exhibits the superior catalytic activity as compared to other two ILs with the protic hydrogen atom in cation along with the same anion.The active hydrogen atom in[DMAPBrPC][TMGH]and[DMAPBrPC][DBUH]would impede the–COO^(-)group to absorb CO 2,which is an unfavorable item for the reaction.Moreover,the strong hydrogen bond in[DMAPBrPC][TMGH]and[DMAPBrPC][DBUH]would lessen the nucleophilic ability of Br^(-) anion resulting in the inferior catalytic performance,which is further confirmed by the density functional theory(DFT)calculations.The cation without the active hydrogen atom could also be employed to design the ILs with the excellent catalytic feature when it is combined with the suitable anion.
