The relative chemical shifts (△δ) △δwere put forward to investigate the microscopic structure of 1-ethyl-3-methyl-imidazolium tetrafluoroborate (EmimBF4) during the dilution process with water.The concentration-de...The relative chemical shifts (△δ) △δwere put forward to investigate the microscopic structure of 1-ethyl-3-methyl-imidazolium tetrafluoroborate (EmimBF4) during the dilution process with water.The concentration-dependent △δ(C2)H-(C4)H,△δ(C2)H-(C5)H and △δ(C4)H-(C5)H were analyzed.The results reveal that the variations of the microscopic structures of three aromatic protons are inconsistent.The strength of the H-bond between water and three aromatic protons follows the order:(C2)H···O 】 (C4)H···O 】 (C5)H···O.The concentration-dependent △δ(C6)H-(C7)H and △δ(C6)H-(C8)H indicate the formation of the H-bonds of (Calkyl)H···O is impossible,and more water is located around (C6)H than around (C7)H or (C8)H.The concentration-dependent △δ(C2)H-(C4)H and △δ(C2)H-(C5)H both increase rapidly when xwater 】 0.9 or so,suggesting the ionic pairs of EmimBF4 are dissociated rapidly.The turning points of concentration-dependent △δ(C2)H-(C4)H and △δ(C2)H-(C5)H indicate that some physical properties of the EmimBF4/water mixtures also change at the corresponding concentration point.The microscopic structures of EmimBF4 in water could be clearly detected by the relative chemical shifts.展开更多
Objective: To optimize the ionic liquid based microwave-assisted extraction (IL-MAE) of polyphenolic content from Peperomia pellucida (L) Kunth. Methods: The IL-MAE factors as experimental design parameters, including...Objective: To optimize the ionic liquid based microwave-assisted extraction (IL-MAE) of polyphenolic content from Peperomia pellucida (L) Kunth. Methods: The IL-MAE factors as experimental design parameters, including microwave power, extraction time, ionic liquid concentration, and liquid–solid ratio had been involved. Response surface methodology and Box–Behnken design were used to obtain predictive model (multivariate quadratic regression equation) and optimization of the extraction process. The response surface was analyzed by using the yields of total polyphenolic content as response value. Results: Based on the obtained results the optimum extraction condition, including microwave power of 30% Watts, extraction time of 18.5 min, the ionic liquid concen-tration of 0.79 mol/L, and the liquid–solid ratio of 10.72 mL/g 1-Buthyl-3-methylimidazolium tetrafluoroborate ([bmim]BF4) as a solvent was selected. The regression model was obtained to predicts the yields from Peperomia pellucida:Y = 30.250 – 1.356X1 + 2.655X2 + 2.252X3 – 0.565X4 + 0.990 X1X3 – 8.172 X1X4 – 3.439 X3X4 – 4.178 X12 – 3.210 X32 – 6.786 X42 – 7.290 X12X3 + 5.575 X1X32 – 4.843 X32X4 with R2 = 0.82519. Scale-up confirmation test was obtained the maximum yields of total polyphenolics content with the amount of 31.1725μg GAE/g. Conclusions: The IL-MAE method produced a higher extraction polyphenolic and performed rapidly, easily and efficiently.展开更多
Reductive amination of aromatic aldehydes using NaBH4 and isoxazole amines is carried out in a Bronsted acidic ionic liquid 1 -methylimidazolium tetrafluoroborate [（HMIm）BF4]. The ionic liquid plays dual roles of so...Reductive amination of aromatic aldehydes using NaBH4 and isoxazole amines is carried out in a Bronsted acidic ionic liquid 1 -methylimidazolium tetrafluoroborate [（HMIm）BF4]. The ionic liquid plays dual roles of solvent as well as catalyst for the efficixcellent yields without any undesired side product formation. The newly synthesized compoundsent transformation of aromatic aldehydes to heterocyclic substituted amines in e （3, 6 and 7） were characterized by IR, 1H NMR and mass spectral techniques.展开更多
建立了离子色谱-间接紫外检测法同时分析离子液体中的三氟乙酸根（CF3COO-）、四氟硼酸根（BF4-）和三氟甲烷磺酸根（CF3SO3-）的方法。用Shodex IC NI-424阴离子交换柱作为分离柱,探讨了影响上述三种离子保留和检测的因素及其保留规律...建立了离子色谱-间接紫外检测法同时分析离子液体中的三氟乙酸根（CF3COO-）、四氟硼酸根（BF4-）和三氟甲烷磺酸根（CF3SO3-）的方法。用Shodex IC NI-424阴离子交换柱作为分离柱,探讨了影响上述三种离子保留和检测的因素及其保留规律。最终选用色谱条件为：以1.75 mmol·L^-1邻苯二甲酸-1.68 mmol·L^-1三（羟甲基）氨基甲烷为淋洗液,柱温45℃,流速1.0 m L·min^-1,UV检测波长设定在265 nm。在此条件下,可实现上述三种阴离子的同时分析,且色谱峰形良好。所测阴离子的检出限（S/N=3）为0.39-1.57 mg·L^-1,保留时间和峰面积的相对标准偏差（n=5）均在1%以下。将此方法应用于测定离子液体中的三氟乙酸根、四氟硼酸根及三氟甲烷磺酸根,加标回收率为99%-102%。该方法简单、准确、可靠,具有较好的实用性。展开更多
Sodium tetrafluoroborate （NaBF4） was found to catalyze the electrophilic substitution reactions of indoles with aldehydes and ketones under solvent-free conditions to afford the corresponding bis（indolyl）methanes ...Sodium tetrafluoroborate （NaBF4） was found to catalyze the electrophilic substitution reactions of indoles with aldehydes and ketones under solvent-free conditions to afford the corresponding bis（indolyl）methanes in high yields.展开更多
A new transition metal complex, [Cu（N-MeIm）4（BF4）2]（N-MeIm=N-methylated imidazoles, BF4= tetrafluoroborate）, was synthesized via the solvothermal method in ionic liquid. The ionic liquid acts as thermal decompos...A new transition metal complex, [Cu（N-MeIm）4（BF4）2]（N-MeIm=N-methylated imidazoles, BF4= tetrafluoroborate）, was synthesized via the solvothermal method in ionic liquid. The ionic liquid acts as thermal decomposition reaction medium, soft temple agent and ligand compound. The central Cu（Ⅱ） ion is coordinated by four N atoms from four N-methylated imidazole ligands, and the four N-methylated imidazole rings are perpendicular to each other. The crystal structure of [Cu（N-MeIm）4（BF4）2] was determined by single crystal X-ray diffraction. The results of thermogravimetry（TG） and Fourier transform infrared spectrometry（FTIR） analyses were in accordance with that of crystal structure. The complex showed strong ligand-based absorbance with maximum wavelength at 208 and 231 nm, which are attributed to π-π＊ transition of the N-methylated imidazole ligands.展开更多
We report a one-pot three-component synthesis of N-arylmethyl-4-(7-cyclohepta-1,3,5-trienyl)anilines by using various aromatic imines, tropylium tetrafluoroborate, and sodium tetrahydroborate in the presence of imidaz...We report a one-pot three-component synthesis of N-arylmethyl-4-(7-cyclohepta-1,3,5-trienyl)anilines by using various aromatic imines, tropylium tetrafluoroborate, and sodium tetrahydroborate in the presence of imidazole as activator.展开更多
The smallest cyclic ammonium salt reported to date, N,N-dimethylpyrrolidinium tetrafluoroborate (P11-BF4), was successively synthesized using a synthesis route without metal ions and halogen ions, then investigated as...The smallest cyclic ammonium salt reported to date, N,N-dimethylpyrrolidinium tetrafluoroborate (P11-BF4), was successively synthesized using a synthesis route without metal ions and halogen ions, then investigated as the electrolyte with Propylene carbonate in EDLCs. The electrochemical characteristics of EDLCs assembled by 1 mol/L P11-BF4/PC paired with activated carbon electrodes were compared to traditional electrolytes. P11-BF4 has proven to have superior voltage resistance by using cyclic voltammetry and constant current charge-discharge testing. Moreover, P11-BF4 exhibits a more brilliant rate performance due to its high conductivity. These results demonstrate that P11-BF4 is an ideal electrolyte to improve the energy density and power density of supercapacitors.展开更多
Four pyrylium salts, (2,6-diphenyl-4-arylpyrylium tetrafluoroborate, aryl = C6H5, 4-MeO C6H4, 4-Me2NC6H4, 4-NO2C6H4) were synthesized efficiently and economically from acetophenone and substituted chalcones in the pre...Four pyrylium salts, (2,6-diphenyl-4-arylpyrylium tetrafluoroborate, aryl = C6H5, 4-MeO C6H4, 4-Me2NC6H4, 4-NO2C6H4) were synthesized efficiently and economically from acetophenone and substituted chalcones in the presence of borontrifluoride.展开更多
Bis (7- diethylaminocoumarin) ketone- 3(DACK) and diphenyliodonium salt (DPIO)combination as an effective photoinitiation system for radical polymerization has been investigated. The sensitized photolysis of DACK/DPIO...Bis (7- diethylaminocoumarin) ketone- 3(DACK) and diphenyliodonium salt (DPIO)combination as an effective photoinitiation system for radical polymerization has been investigated. The sensitized photolysis of DACK/DPIO leads to bleaching of DACK and decomposition of DPIO to generate initiating radical species. The electron transfer sensitization occurs mainly from the triplet state of DACK. The photobleaching obeyed a second-order kinetics and the rate constant was evaluated to be 31.3mol^(-1)·1·s^(-1) Photopolymerization of MMA initiated by DACK/DPIO was carried out in acetonitrile solution. The polymerization rate was found to be proportional to the concentration of DACK, DPIO and MMA with the exponents of 0.34, 0.40 and 1.0 respectively. The initiated efficiency is comparable to those of small molecular ketones.The sensitized photoinitiation mechanism has been discussed.展开更多
基金the National Natural Science Foundation of China (20773109 & 20704035)the Natural Science Foundation of Zhejiang Province (Y4090453)
文摘The relative chemical shifts (△δ) △δwere put forward to investigate the microscopic structure of 1-ethyl-3-methyl-imidazolium tetrafluoroborate (EmimBF4) during the dilution process with water.The concentration-dependent △δ(C2)H-(C4)H,△δ(C2)H-(C5)H and △δ(C4)H-(C5)H were analyzed.The results reveal that the variations of the microscopic structures of three aromatic protons are inconsistent.The strength of the H-bond between water and three aromatic protons follows the order:(C2)H···O 】 (C4)H···O 】 (C5)H···O.The concentration-dependent △δ(C6)H-(C7)H and △δ(C6)H-(C8)H indicate the formation of the H-bonds of (Calkyl)H···O is impossible,and more water is located around (C6)H than around (C7)H or (C8)H.The concentration-dependent △δ(C2)H-(C4)H and △δ(C2)H-(C5)H both increase rapidly when xwater 】 0.9 or so,suggesting the ionic pairs of EmimBF4 are dissociated rapidly.The turning points of concentration-dependent △δ(C2)H-(C4)H and △δ(C2)H-(C5)H indicate that some physical properties of the EmimBF4/water mixtures also change at the corresponding concentration point.The microscopic structures of EmimBF4 in water could be clearly detected by the relative chemical shifts.
基金funded by Directorate of Research and Humanity Engagement (DRPM), Universitas Indonesia via grant “Hibah PITTA 2017” with No. 328/UN2.R3.1/HKP.05.00/ 2017
文摘Objective: To optimize the ionic liquid based microwave-assisted extraction (IL-MAE) of polyphenolic content from Peperomia pellucida (L) Kunth. Methods: The IL-MAE factors as experimental design parameters, including microwave power, extraction time, ionic liquid concentration, and liquid–solid ratio had been involved. Response surface methodology and Box–Behnken design were used to obtain predictive model (multivariate quadratic regression equation) and optimization of the extraction process. The response surface was analyzed by using the yields of total polyphenolic content as response value. Results: Based on the obtained results the optimum extraction condition, including microwave power of 30% Watts, extraction time of 18.5 min, the ionic liquid concen-tration of 0.79 mol/L, and the liquid–solid ratio of 10.72 mL/g 1-Buthyl-3-methylimidazolium tetrafluoroborate ([bmim]BF4) as a solvent was selected. The regression model was obtained to predicts the yields from Peperomia pellucida:Y = 30.250 – 1.356X1 + 2.655X2 + 2.252X3 – 0.565X4 + 0.990 X1X3 – 8.172 X1X4 – 3.439 X3X4 – 4.178 X12 – 3.210 X32 – 6.786 X42 – 7.290 X12X3 + 5.575 X1X32 – 4.843 X32X4 with R2 = 0.82519. Scale-up confirmation test was obtained the maximum yields of total polyphenolics content with the amount of 31.1725μg GAE/g. Conclusions: The IL-MAE method produced a higher extraction polyphenolic and performed rapidly, easily and efficiently.
文摘Reductive amination of aromatic aldehydes using NaBH4 and isoxazole amines is carried out in a Bronsted acidic ionic liquid 1 -methylimidazolium tetrafluoroborate [（HMIm）BF4]. The ionic liquid plays dual roles of solvent as well as catalyst for the efficixcellent yields without any undesired side product formation. The newly synthesized compoundsent transformation of aromatic aldehydes to heterocyclic substituted amines in e （3, 6 and 7） were characterized by IR, 1H NMR and mass spectral techniques.
文摘建立了离子色谱-间接紫外检测法同时分析离子液体中的三氟乙酸根（CF3COO-）、四氟硼酸根（BF4-）和三氟甲烷磺酸根（CF3SO3-）的方法。用Shodex IC NI-424阴离子交换柱作为分离柱,探讨了影响上述三种离子保留和检测的因素及其保留规律。最终选用色谱条件为：以1.75 mmol·L^-1邻苯二甲酸-1.68 mmol·L^-1三（羟甲基）氨基甲烷为淋洗液,柱温45℃,流速1.0 m L·min^-1,UV检测波长设定在265 nm。在此条件下,可实现上述三种阴离子的同时分析,且色谱峰形良好。所测阴离子的检出限（S/N=3）为0.39-1.57 mg·L^-1,保留时间和峰面积的相对标准偏差（n=5）均在1%以下。将此方法应用于测定离子液体中的三氟乙酸根、四氟硼酸根及三氟甲烷磺酸根,加标回收率为99%-102%。该方法简单、准确、可靠,具有较好的实用性。
文摘Sodium tetrafluoroborate （NaBF4） was found to catalyze the electrophilic substitution reactions of indoles with aldehydes and ketones under solvent-free conditions to afford the corresponding bis（indolyl）methanes in high yields.
基金Supported by the National Natural Science Foundation of China（Nos. 51104050, 51301050, 51202047）, the Natural Science Foundation of Heilongjiang Province, China（No. E201413）, the Technology Foundation for Selected Overseas Chinese Scholar of Heilongjiang Province, China（No. 159150130002）, the Postdoctoral Scientific Research Developmental Fund of Heilongjiang Province, China（No.LBH-3236310448） and the Fundamental Research Funds for the Central Universities, China（No. GK2150260120）.
文摘A new transition metal complex, [Cu（N-MeIm）4（BF4）2]（N-MeIm=N-methylated imidazoles, BF4= tetrafluoroborate）, was synthesized via the solvothermal method in ionic liquid. The ionic liquid acts as thermal decomposition reaction medium, soft temple agent and ligand compound. The central Cu（Ⅱ） ion is coordinated by four N atoms from four N-methylated imidazole ligands, and the four N-methylated imidazole rings are perpendicular to each other. The crystal structure of [Cu（N-MeIm）4（BF4）2] was determined by single crystal X-ray diffraction. The results of thermogravimetry（TG） and Fourier transform infrared spectrometry（FTIR） analyses were in accordance with that of crystal structure. The complex showed strong ligand-based absorbance with maximum wavelength at 208 and 231 nm, which are attributed to π-π＊ transition of the N-methylated imidazole ligands.
文摘We report a one-pot three-component synthesis of N-arylmethyl-4-(7-cyclohepta-1,3,5-trienyl)anilines by using various aromatic imines, tropylium tetrafluoroborate, and sodium tetrahydroborate in the presence of imidazole as activator.
基金financially supported by the Guangdong Power Grid Co., Ltd. (No. GDKJXM20160000)
文摘The smallest cyclic ammonium salt reported to date, N,N-dimethylpyrrolidinium tetrafluoroborate (P11-BF4), was successively synthesized using a synthesis route without metal ions and halogen ions, then investigated as the electrolyte with Propylene carbonate in EDLCs. The electrochemical characteristics of EDLCs assembled by 1 mol/L P11-BF4/PC paired with activated carbon electrodes were compared to traditional electrolytes. P11-BF4 has proven to have superior voltage resistance by using cyclic voltammetry and constant current charge-discharge testing. Moreover, P11-BF4 exhibits a more brilliant rate performance due to its high conductivity. These results demonstrate that P11-BF4 is an ideal electrolyte to improve the energy density and power density of supercapacitors.
文摘Four pyrylium salts, (2,6-diphenyl-4-arylpyrylium tetrafluoroborate, aryl = C6H5, 4-MeO C6H4, 4-Me2NC6H4, 4-NO2C6H4) were synthesized efficiently and economically from acetophenone and substituted chalcones in the presence of borontrifluoride.
文摘Bis (7- diethylaminocoumarin) ketone- 3(DACK) and diphenyliodonium salt (DPIO)combination as an effective photoinitiation system for radical polymerization has been investigated. The sensitized photolysis of DACK/DPIO leads to bleaching of DACK and decomposition of DPIO to generate initiating radical species. The electron transfer sensitization occurs mainly from the triplet state of DACK. The photobleaching obeyed a second-order kinetics and the rate constant was evaluated to be 31.3mol^(-1)·1·s^(-1) Photopolymerization of MMA initiated by DACK/DPIO was carried out in acetonitrile solution. The polymerization rate was found to be proportional to the concentration of DACK, DPIO and MMA with the exponents of 0.34, 0.40 and 1.0 respectively. The initiated efficiency is comparable to those of small molecular ketones.The sensitized photoinitiation mechanism has been discussed.
