The alkylation mechanism catalyzed by an ionic liquid （as a Lewis acid） may be different from the traditional alkylation mechanism catalyzed by Br nsted acid,especially as their initiation steps are still not clear....The alkylation mechanism catalyzed by an ionic liquid （as a Lewis acid） may be different from the traditional alkylation mechanism catalyzed by Br nsted acid,especially as their initiation steps are still not clear.In this paper,an isotope exchange method is used to investigate the catalytic mechanism of AlCl 3 /butyl-methyl-imidazolium chloride ionic liquid in the alkylation of benzene with 1-dodecene.The proposed catalytic mechanism was confirmed by analysis of ionic liquid before and after reaction and of the alkylation products of deuterated benzene （C 6 D 6） with 1-dodecene.The proposed mechanism consists of the equilibrium reaction between [Al 2 Cl 7 ] ＋H ＋ and [AlHCl 3 ] ＋ ＋[AlCl 4 ],in which the Br nsted acid [AlHCl 3 ] ＋ is supplied by the reaction of 2-H on the imidazolium ring and [Al 2 Cl 7 ].The alkylation reaction is initiated by the Br nsted acid [AlHCl 3 ] ＋ which reacts with 1-dodecene to form a carbonium ion,then the carbonium ion reacts with benzene to form an unstable σ complex,leading to the formation of 2-phenyldodecane.展开更多
In this article,an efficient,simple and environmentally friendly approach to the synthesis of diacetals(diketals) pentaerythritol using SOH-functionalized ionic liquids(ILs) as catalysts was reported.The ILs show high...In this article,an efficient,simple and environmentally friendly approach to the synthesis of diacetals(diketals) pentaerythritol using SOH-functionalized ionic liquids(ILs) as catalysts was reported.The ILs show high catalytic activity and reusability with good to excellent yields of the desired products.Hammett method has been used to determine the acidity order of these ionic liquids and the results are consistent with the catalytic activities observed in acetalization reaction.Maximum product yield of 93%was observed on using[PSPy][OTf]as catalyst and it can be reused at least 8 times without obvious activity loss.展开更多
Development of a predictive tool for H_2S solubility estimation can be very helpful in gas sweetening industry. Experimental databases on H_2 S solubility were rarely available, so as reliable predictive models. Thus,...Development of a predictive tool for H_2S solubility estimation can be very helpful in gas sweetening industry. Experimental databases on H_2 S solubility were rarely available, so as reliable predictive models. Thus, in this study the H_2 S solubility database was established, and then a Least-Squares Support Vector Machine(LSSVM) approach based on the established database is proposed. Group contribution method was also applied to eliminate the model's dependence on experimental data. Accordingly, our proposed LSSVM model can predict H_2 S solubility as a function of temperature, pressure, and 15 different chemical structures of Ionic liquids(ILs). Root Mean Square Error(RMSE) and coefficient of determination(R^2) are 0.0122 and 0.9941, respectively. Moreover, comparison of our model with other existing models showed its reliability for H_2 S solubility in ILs. This can be very useful for engineers dealing with gas sweetening process in different applications of analysis, simulation, and designation.展开更多
In this study, a modified silica gel surface with a hydrophobic ionic liquid (SG-1,10-PhenanNTf2) was used as an adsorbent for a selective extraction of coumarin prior to its determination by use of high performance l...In this study, a modified silica gel surface with a hydrophobic ionic liquid (SG-1,10-PhenanNTf2) was used as an adsorbent for a selective extraction of coumarin prior to its determination by use of high performance liquid chromatography. Results demonstrated that SG-1,10-PhenanNTf2 phase had a good adsorption capacity up to 85.29 mg?g?1, high selectivity, good site accessibility and fast binding kinetics toward coumarin. The adsorption capacity for coumarin was improved by 62.33% with the SG-1,10-PhenanNTf2 phase as compared to activated silica gel. Adsorption isotherm data displayed that the adsorption process was mainly monolayer on a homogeneous adsorbent surface, confirming the validity of Langmuir adsorption isotherm model. The adsorption of coumarin on the SG-1,10-PhenanNTf2 phase was accomplished after only 60 min contact time. Results of kinetic models showed that the adsorption of coumarin on the SG-1,10-PhenanNTf2 phase obeyed a pseudo second-order kinetic model. Finally, the efficiency of this methodology was confirmed by applying it to real water samples.展开更多
In this study we used the deep eutectic solvents (ionic liquids) to investigate the reaction between copper (II) with ethylene diamine (en). Two of the existing methods for analyzing spectrophotometric measurements ha...In this study we used the deep eutectic solvents (ionic liquids) to investigate the reaction between copper (II) with ethylene diamine (en). Two of the existing methods for analyzing spectrophotometric measurements have been applied for establishing, the stoichiometry and whenever possible, the stability constants of the chelates formed. The method of continuous variations was necessary to determine first whether, the metal ion and the ligand ethylene diamine form one or more than one chelate, when more than one chelate formed, the results obtained depend on the wavelength and for meaningful conclusions the wavelengths were carefully selected. The empirical formulae of the chelates were further substantiated by the molar ratio method. The effect of time and temperature on the formation and stability of these chelates in solution is also studied. The stability constants, K1 and K2 for the copper (II) chelates were calculated, though reliable, and are comparable to literature values.展开更多
A novel method for fluorination of halopyridazine derivatives with potassium fluoride was performed using a green chemistry procedure, including ionic liquid as an environmentally benign reaction medium and microwave ...A novel method for fluorination of halopyridazine derivatives with potassium fluoride was performed using a green chemistry procedure, including ionic liquid as an environmentally benign reaction medium and microwave irradiation with high yield.展开更多
基金financial support from the National Natural Science Foundation of China (NSFC,2052010)
文摘The alkylation mechanism catalyzed by an ionic liquid （as a Lewis acid） may be different from the traditional alkylation mechanism catalyzed by Br nsted acid,especially as their initiation steps are still not clear.In this paper,an isotope exchange method is used to investigate the catalytic mechanism of AlCl 3 /butyl-methyl-imidazolium chloride ionic liquid in the alkylation of benzene with 1-dodecene.The proposed catalytic mechanism was confirmed by analysis of ionic liquid before and after reaction and of the alkylation products of deuterated benzene （C 6 D 6） with 1-dodecene.The proposed mechanism consists of the equilibrium reaction between [Al 2 Cl 7 ] ＋H ＋ and [AlHCl 3 ] ＋ ＋[AlCl 4 ],in which the Br nsted acid [AlHCl 3 ] ＋ is supplied by the reaction of 2-H on the imidazolium ring and [Al 2 Cl 7 ].The alkylation reaction is initiated by the Br nsted acid [AlHCl 3 ] ＋ which reacts with 1-dodecene to form a carbonium ion,then the carbonium ion reacts with benzene to form an unstable σ complex,leading to the formation of 2-phenyldodecane.
基金supported by National 863 High-Tech Research and Development Program of China(No. 2007AA05Z101)
文摘In this article,an efficient,simple and environmentally friendly approach to the synthesis of diacetals(diketals) pentaerythritol using SOH-functionalized ionic liquids(ILs) as catalysts was reported.The ILs show high catalytic activity and reusability with good to excellent yields of the desired products.Hammett method has been used to determine the acidity order of these ionic liquids and the results are consistent with the catalytic activities observed in acetalization reaction.Maximum product yield of 93%was observed on using[PSPy][OTf]as catalyst and it can be reused at least 8 times without obvious activity loss.
文摘Development of a predictive tool for H_2S solubility estimation can be very helpful in gas sweetening industry. Experimental databases on H_2 S solubility were rarely available, so as reliable predictive models. Thus, in this study the H_2 S solubility database was established, and then a Least-Squares Support Vector Machine(LSSVM) approach based on the established database is proposed. Group contribution method was also applied to eliminate the model's dependence on experimental data. Accordingly, our proposed LSSVM model can predict H_2 S solubility as a function of temperature, pressure, and 15 different chemical structures of Ionic liquids(ILs). Root Mean Square Error(RMSE) and coefficient of determination(R^2) are 0.0122 and 0.9941, respectively. Moreover, comparison of our model with other existing models showed its reliability for H_2 S solubility in ILs. This can be very useful for engineers dealing with gas sweetening process in different applications of analysis, simulation, and designation.
文摘In this study, a modified silica gel surface with a hydrophobic ionic liquid (SG-1,10-PhenanNTf2) was used as an adsorbent for a selective extraction of coumarin prior to its determination by use of high performance liquid chromatography. Results demonstrated that SG-1,10-PhenanNTf2 phase had a good adsorption capacity up to 85.29 mg?g?1, high selectivity, good site accessibility and fast binding kinetics toward coumarin. The adsorption capacity for coumarin was improved by 62.33% with the SG-1,10-PhenanNTf2 phase as compared to activated silica gel. Adsorption isotherm data displayed that the adsorption process was mainly monolayer on a homogeneous adsorbent surface, confirming the validity of Langmuir adsorption isotherm model. The adsorption of coumarin on the SG-1,10-PhenanNTf2 phase was accomplished after only 60 min contact time. Results of kinetic models showed that the adsorption of coumarin on the SG-1,10-PhenanNTf2 phase obeyed a pseudo second-order kinetic model. Finally, the efficiency of this methodology was confirmed by applying it to real water samples.
文摘In this study we used the deep eutectic solvents (ionic liquids) to investigate the reaction between copper (II) with ethylene diamine (en). Two of the existing methods for analyzing spectrophotometric measurements have been applied for establishing, the stoichiometry and whenever possible, the stability constants of the chelates formed. The method of continuous variations was necessary to determine first whether, the metal ion and the ligand ethylene diamine form one or more than one chelate, when more than one chelate formed, the results obtained depend on the wavelength and for meaningful conclusions the wavelengths were carefully selected. The empirical formulae of the chelates were further substantiated by the molar ratio method. The effect of time and temperature on the formation and stability of these chelates in solution is also studied. The stability constants, K1 and K2 for the copper (II) chelates were calculated, though reliable, and are comparable to literature values.
文摘A novel method for fluorination of halopyridazine derivatives with potassium fluoride was performed using a green chemistry procedure, including ionic liquid as an environmentally benign reaction medium and microwave irradiation with high yield.
