The random copolymer poly （1, 3-pentadiene-co-styrene） formed through cationic copolymerization using the ~ethylamine hydrochloride and hydrous aluminium chloride （Et3NHCl-AlCl3） room temperature ionic liquid as i...The random copolymer poly （1, 3-pentadiene-co-styrene） formed through cationic copolymerization using the ~ethylamine hydrochloride and hydrous aluminium chloride （Et3NHCl-AlCl3） room temperature ionic liquid as initiating agent in toluene was analyzed using IR spectra in conjunction with gel permeation chromatography （GPC）. The room temperature ionic liquid was found to have high initiatic activity for copolymerization.展开更多
Silica-grafted N-propyl-imidazolium hydrogen sulfate ([Sipim]HSO4) is employed as a recyclable heterogeneous ionic liquid catalyst for the synthesis of 3,4-dihydropyrano[c]-chromenes by the reaction of aromatic aldehy...Silica-grafted N-propyl-imidazolium hydrogen sulfate ([Sipim]HSO4) is employed as a recyclable heterogeneous ionic liquid catalyst for the synthesis of 3,4-dihydropyrano[c]-chromenes by the reaction of aromatic aldehydes, malononitrile and 4-hydroxycoumarin at 100°C under solvent-free conditions. Also, heterogeneous ionic liquid catalyst was used for the synthesis of pyrano[2,3-c]-pyrazoles by the reaction of aromatic aldehydes, malononitrile and 3-methyl-l-phenyl-5-pyrazolone at 110°C under solvent-free conditions. The heterogeneous ionic liquid showed much the same efficiency when used in consecutive reaction runs.展开更多
The development of heterogeneous acid catalysts with higher activity than homogeneous acid catalysts is critical and still challenging.In this study,acidic poly(ionic liquid)s with swelling ability(SAPILs)were designe...The development of heterogeneous acid catalysts with higher activity than homogeneous acid catalysts is critical and still challenging.In this study,acidic poly(ionic liquid)s with swelling ability(SAPILs)were designed and synthesized via the free radical copolymerization of ionic liquid monomers,sodium p-styrenesulfonate,and crosslinkers,followed by acidification.The 31P nuclear magnetic resonance chemical shifts of adsorbed trimethylphosphine oxide indicated that the synthesized SAPILs presented moderate and single acid strength.The thermogravimetric analysis results in the temperature range of 300–345°C revealed that the synthesized SAPILs were more stable than the commercial resin Amberlite IR-120(H)(245°C).Cryogenic scanning electron microscopy testing demonstrated that SAPILs presented unique three-dimensional(3D)honeycomb structure in water,which was ascribed to the swelling-induced self-assembly of the molecules.Moreover,we used SAPILs with micron-sized honeycomb structure in water as catalysts for the hydrolysis of cyclohexyl acetate to cyclohexanol,and determined that their catalytic activity was much higher than that of homogeneous acid catalysts.The equilibrium concentrations of all reaction components inside and outside the synthesized SAPILs were quantitatively analyzed using a series of simulated reaction mixtures.Depending on the reaction mixture,the concentration of cyclohexyl acetate inside SAPIL-1 was 7.5–23.3 times higher than that outside of it,which suggested the high enrichment ability of SAPILs for cyclohexyl acetate.The excellent catalytic performance of SAPILs was attributed to their 3D honeycomb structure in water and high enrichment ability for cyclohexyl acetate,which opened up new avenues for designing highly efficient heterogeneous acid catalysts that could eventually replace conventional homogeneous acid catalysts.展开更多
Lewis acidic ionic liquids were used to catalyze the reaction of epoxypropane with POCl3. Considering the lower cost and catalytic activities, we concluded that [Et3NH]Cl/AlCl3 was the most attractive ionic liquid fro...Lewis acidic ionic liquids were used to catalyze the reaction of epoxypropane with POCl3. Considering the lower cost and catalytic activities, we concluded that [Et3NH]Cl/AlCl3 was the most attractive ionic liquid from an economical point of view. But it would be easily inactivated because of sensitive to water and air. Moreover, it could not be reused easily because of difficulty recovery in the reaction. However, supporting [Et3NH]Cl/AlCl3 catalyst could resolve above problems. Supporting [Et3NH]Cl/ AlCl3 catalyst could be separated by filter easily and reused 5 times in 98% yield. Furthermore, the catalyst was applicable to other epoxy ether cleaving reactions.展开更多
文摘The random copolymer poly （1, 3-pentadiene-co-styrene） formed through cationic copolymerization using the ~ethylamine hydrochloride and hydrous aluminium chloride （Et3NHCl-AlCl3） room temperature ionic liquid as initiating agent in toluene was analyzed using IR spectra in conjunction with gel permeation chromatography （GPC）. The room temperature ionic liquid was found to have high initiatic activity for copolymerization.
文摘Silica-grafted N-propyl-imidazolium hydrogen sulfate ([Sipim]HSO4) is employed as a recyclable heterogeneous ionic liquid catalyst for the synthesis of 3,4-dihydropyrano[c]-chromenes by the reaction of aromatic aldehydes, malononitrile and 4-hydroxycoumarin at 100°C under solvent-free conditions. Also, heterogeneous ionic liquid catalyst was used for the synthesis of pyrano[2,3-c]-pyrazoles by the reaction of aromatic aldehydes, malononitrile and 3-methyl-l-phenyl-5-pyrazolone at 110°C under solvent-free conditions. The heterogeneous ionic liquid showed much the same efficiency when used in consecutive reaction runs.
文摘The development of heterogeneous acid catalysts with higher activity than homogeneous acid catalysts is critical and still challenging.In this study,acidic poly(ionic liquid)s with swelling ability(SAPILs)were designed and synthesized via the free radical copolymerization of ionic liquid monomers,sodium p-styrenesulfonate,and crosslinkers,followed by acidification.The 31P nuclear magnetic resonance chemical shifts of adsorbed trimethylphosphine oxide indicated that the synthesized SAPILs presented moderate and single acid strength.The thermogravimetric analysis results in the temperature range of 300–345°C revealed that the synthesized SAPILs were more stable than the commercial resin Amberlite IR-120(H)(245°C).Cryogenic scanning electron microscopy testing demonstrated that SAPILs presented unique three-dimensional(3D)honeycomb structure in water,which was ascribed to the swelling-induced self-assembly of the molecules.Moreover,we used SAPILs with micron-sized honeycomb structure in water as catalysts for the hydrolysis of cyclohexyl acetate to cyclohexanol,and determined that their catalytic activity was much higher than that of homogeneous acid catalysts.The equilibrium concentrations of all reaction components inside and outside the synthesized SAPILs were quantitatively analyzed using a series of simulated reaction mixtures.Depending on the reaction mixture,the concentration of cyclohexyl acetate inside SAPIL-1 was 7.5–23.3 times higher than that outside of it,which suggested the high enrichment ability of SAPILs for cyclohexyl acetate.The excellent catalytic performance of SAPILs was attributed to their 3D honeycomb structure in water and high enrichment ability for cyclohexyl acetate,which opened up new avenues for designing highly efficient heterogeneous acid catalysts that could eventually replace conventional homogeneous acid catalysts.
基金A Project Funded by Jiangsu Natural Science Foundation of China(No.BK2011369)
文摘Lewis acidic ionic liquids were used to catalyze the reaction of epoxypropane with POCl3. Considering the lower cost and catalytic activities, we concluded that [Et3NH]Cl/AlCl3 was the most attractive ionic liquid from an economical point of view. But it would be easily inactivated because of sensitive to water and air. Moreover, it could not be reused easily because of difficulty recovery in the reaction. However, supporting [Et3NH]Cl/AlCl3 catalyst could resolve above problems. Supporting [Et3NH]Cl/ AlCl3 catalyst could be separated by filter easily and reused 5 times in 98% yield. Furthermore, the catalyst was applicable to other epoxy ether cleaving reactions.
