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1.
Lijin Zhang Yanling Geng Wenjuan Duan Daijie Wang Maorun Fu Xiao Wang 《Journal of separation science》2009,32(20):3550-3554
An ionic liquid‐based ultrasound‐assisted extraction method has been developed for the effective extraction of fangchinoline and tetrandrine from Stephaniae tetrandrae. The effects of some ultrasound‐assisted extraction parameters including the concentration of [BMIM][BF4], pH, ultrasonic power and time were investigated to optimize the ultrasound‐assisted extraction conditions. Compared to the regular ultrasound‐assisted extraction and traditional refluent extraction, the proposed [BMIM][BF4]‐based ultrasound‐assisted extraction offered shorter extraction times (from 6 h to 40 min) and remarkable higher efficiencies (approximately 30% improved), which supported the suitability of the proposed approach. In addition, the proposed approach was confirmed by the good correlation coefficient (R2), recovery and reproducibility (RSD, n = 5), which were in the range of 0.9992–0.9995, 85.5–101.1%, and 1.87–4.33%, respectively. 相似文献
2.
Five different imidazolium‐based ionic liquids (ILs) were incorporated into a metal–organic framework (MOF), MIL‐53(Al), to investigate the effect of IL incorporation on the CO2 separation performance of MIL‐53(Al). CO2, CH4, and N2 adsorption isotherms of the IL/MIL‐53(Al) composites and pristine MIL‐53(Al) were measured to evaluate the effect of the ILs on the CO2/CH4 and CO2/N2 selectivities of the MOF. Of the composite materials that were tested, [BMIM][PF6]/MIL‐53(Al) exhibited the largest increase in CO2/CH4 selectivity, 2.8‐times higher than that of pristine MIL‐53(Al), whilst [BMIM][MeSO4]/MIL‐53(Al) exhibited the largest increase in CO2/N2 selectivity, 3.3‐times higher than that of pristine MIL‐53(Al). A comparison of the CO2 separation potentials of the IL/MOF composites showed that the [BMIM][BF4]‐ and [BMIM][PF6]‐incorporated MIL‐53(Al) composites both showed enhanced CO2/N2 and CO2/CH4 selectivities at pressures of 1–5 bar compared to composites of CuBTC and ZIF‐8 with the same ILs. These results demonstrate that MIL‐53(Al) is a versatile platform for IL/MOF composites and could help to guide the rational design of new composites for target gas‐separation applications. 相似文献
3.
The determination of triazine herbicides by ultrasonic‐assisted ionic liquid microextraction coupled with high‐performance liquid chromatography was described. 1‐Hexyl‐3‐methylimidazolium hexafluorophosphate ([C6MIm][PF6]) was used as the extraction solvent and some extraction parameters, including volume of [C6MIm][PF6], extraction temperature and time, salt concentration and pH values of sample solution, were examined and optimized. The isolation of the target compounds from the matrix was found to be efficient when triazines in 10 mL of sample solution was extracted with 100 µL of [C6MIm][PF6] for 40 min at 50°C. The detection limits for the triazine range from 0.36 to 1.41 µg·L?1. The satisfactory recoveries (82.3% –120.3%) with relative standard deviations ≦10.1% were obtained for the four triazine herbicides from six kinds of practical water samples. 相似文献
4.
Hechun Lin Peter W. de Oliveira Ingrid Grobelsek Aude Haettich Prof. Dr. Dr. h. c. Michael Veith 《无机化学与普通化学杂志》2010,636(11):1947-1954
The solvothermal reactions of Ti(OiPr)4 in alcohol using ionic liquid as additive were investigated. In the presence of [BMIM][Cl], [BMIM][Br], [BMIM][NTf2], [BMIM][SO3Me], [BMIM][SO4Me], or [BMIM][OTf] (BMIM = 1‐Butyl‐3‐methylimidazolium), pure anatase nanoparticles were obtained. The controlled hydrolysis of Ti(OiPr)4 in the presence of ionic liquids to form titanium oxo clusters plays a key role in the formation of anatase nanostructures, and ionic liquids can be repeatedly used to synthesise anatase nanoparticles. However, in the presence of [BMIM][PF6], [BMIM]2[Ti(OH)6] was obtained by an anion exchange reaction. 相似文献
5.
Wenwen Tu Jianping Lei Dr. Huangxian Ju Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(3):779-784
A functional composite of single‐walled carbon nanotubes (SWNTs) with hematin, a water‐insoluble porphyrin, was first prepared in 1‐butyl‐3‐methylimidazolium hexafluorophosphate ([BMIM][PF6]) ionic liquid. The novel composite in ionic liquid was characterized by scanning electron microscopy, ultraviolet absorption spectroscopy, and electrochemical impedance spectroscopy, and showed a pair of direct redox peaks of the FeIII/FeII couple. The composite–[BMIM][PF6]‐modified glassy carbon electrode showed excellent electrocatalytic activity toward the reduction of trichloroacetic acid (TCA) in neutral media due to the synergic effect among SWNTs, [BMIM][PF6], and porphyrin, which led to a highly sensitive and stable amperometric biosensor for TCA with a linear range from 9.0×10?7 to 1.4×10?4 M . The detection limit was 3.8×10?7 M at a signal‐to‐noise ratio of 3. The TCA biosensor had good analytical performance, such as rapid response, good reproducibility, and acceptable accuracy, and could be successfully used for the detection of residual TCA in polluted water. The functional composite in ionic liquid provides a facile way to not only obtain the direct electrochemistry of water‐insoluble porphyrin, but also construct novel biosensors for monitoring analytes in real environmental samples. 相似文献
6.
In this study, a kind of green solvent named polyethylene glycol (PEG) was developed for the ultrasound-assisted extraction (UAE) of magnolol and honokiol from Cortex Magnoliae Officinalis. The effects of PEG molecular weight, PEG concentration, sample size, pH, ultrasonic power and extraction time on the extraction of magnolol and honokiol were investigated to optimise the extraction conditions. Under the optimal extraction conditions, the PEG-based UAE supplied higher extraction efficiencies of magnolol and honokiol than the ethanol-based UAE and traditional ethanol-reflux extraction. Furthermore, the correlation coefficient (R2), repeatability (relative standard deviation, n = 6) and recovery confirmed the validation of the proposed extraction method, which were 0.9993–0.9996, 3.1–4.6% and 92.3–106.8%, respectively. 相似文献
7.
Hou Chen Lingfang Chen Chunhua Wang Rongjun Qu 《Journal of polymer science. Part A, Polymer chemistry》2011,49(4):1046-1049
Atom transfer radical polymerization using activators regenerated by electron transfer (ARGET ATRP) of acrylonitrile (AN) was first approached with 1‐(1‐ethoxycarbonylethyl)‐3‐methylimidazolium tetrafluoroborate ([ecemim][BF4]) as reaction medium and tin(II) bis(2‐ethylhexanoate) (Sn(EH)2) as reducing agent in the presence of air. When compared with in bulk, an obvious increase of polymer isotacticity was observed for ARGET ATRP of AN in 1‐(1‐ethoxycarbonylethyl)‐3‐methylimidazolium hexafluorophospate ([ecemim][PF6]), the reaction rate of ARGET ATRP of AN in [ecemim][PF6] was higher and the polymerization process was better controlled. The block copolymer polyacrylonitrile‐block‐poly(methyl methacrylate) with molecular weight at 69,750, distribution at 1.34, and isotacticity at 0.36 was successfully obtained in [ecemim][PF6]. [Ecemim][PF6] and the catalyst system were recycled and reused and had no effect on the living nature of polymerization. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011 相似文献
8.
《The Journal of chemical thermodynamics》2006,38(5):624-633
Density and speed of sound measurements have been made on the systems containing the ionic liquid 1-n-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF6]) and some organic solvents having a wide range of dielectric constants. Similar studies have been carried out for tetrabutylammonium hexafluorophosphate ([TBA][PF6]), which has common anion ([PF6]−) with the studied ionic liquid. For the systems investigated, the apparent molar volumes and apparent molar isentropic compressibilities were determined and fitted to the Redlich–Mayer and the Pitzer equations from which the corresponding limiting values were obtained. These limiting values were used to obtain some information about ion–solvent interactions. Furthermore, using the ionic limiting apparent volume values for [TBA]+ from the literature and limiting apparent molar volume for the ionic liquid and [TBA][PF6] obtained in this work, the ionic limiting apparent molar volume values for the cation [BMIM]+ in different organic solvents were also estimated. 相似文献
9.
Room temperature ionic liquid as a novel medium for liquid/liquid extraction of metal ions 总被引:2,自引:0,他引:2
Room temperature ionic liquids (RTILs) have been used as novel solvents to replace traditional volatile organic solvents in organic synthesis, solvent extraction, and electrochemistry. The hydrophobic character and water immiscibility of certain ionic liquids allow their use in solvent extraction of hydrophobic compounds. In this work, a typical room temperature ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate [C4mim][PF6], was used as an alternative solvent to study liquid/liquid extraction of heavy metal ions. Dithizone was employed as a metal chelator to form neutral metal-dithizone complexes with heavy metal ions to extract metal ions from aqueous solution into [C4mim][PF6]. This extraction is possible due to the high distribution ratios of the metal complexes between [C4mim][PF6] and aqueous phase. Since the distribution ratios of metal dithiozonates between [C4mim][PF6] and aqueous phase are strongly pH dependent, the extraction efficiencies of metal complexes can be manipulated by tailoring the pH value of the extraction system. Hence, the extraction, separation, and preconcentraction of heavy metal ions with the biphasic system of [C4mim][PF6] and aqueous phase can be achieved by controlling the pH value of the extraction system. Preliminary results indicate that the use of [C4mim][PF6] as an alternate solvent to replace traditional organic solvents in liquid/liquid extraction of heavy metal ions is very promising. 相似文献
10.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(6):1627-1631
The heterometallic complexes trans ‐[Cp(dppe)FeNCRu(o ‐bpy)CNFe(dppe)Cp][PF6]n ( 1 [PF6]n , n =2, 3, 4; o ‐bpy=1,2‐bis(2,2′‐bipyridyl‐6‐yl)ethane, dppe=1,2‐bis(diphenylphosphino)ethane, Cp=1,3‐cyclopentadiene) in three distinct states have been synthesized and fully characterized. 1 3+[PF6]3 and 1 4+[PF6]4 are the one‐ and two‐electron oxidation products of 1 2+[PF6]2, respectively. The investigated results suggest that 1 [PF6]3 is a Class II mixed valence compound. 1 [PF6]4 after a thermal treatment at 400 K shows an unusually delocalized mixed valence state of [FeIII‐NC‐RuIII‐CN‐FeII], which is induced by electron transfer from the central RuII to the terminal FeIII in 1 [PF6]4, which was confirmed by IR spectroscopy, magnetic data, and EPR and Mössbauer spectroscopy. 相似文献
11.
12.
Bing Peng Xiaoling Yang Jiaheng Zhang Fengpei Du Wenfeng Zhou Haixiang Gao Runhua Lu 《Journal of separation science》2013,36(13):2196-2202
An ultrasound‐enhanced in situ solvent formation microextraction has been developed first time and compared with ultrasound‐enhanced ionic‐liquid‐assisted dispersive liquid–liquid microextraction for the HPLC analysis of acaricides in environmental water samples. A ionic liquid ([C8MIM][PF6]) was used as the green extraction solvent through two pathways. The experimental parameters, such as the type and volume of both of the extraction solvent disperser solvent, ultrasonication time, and salt addition, were investigated and optimized. The analytical performance using the optimized conditions proved the feasibility of the developed methods for the quantitation of trace levels of acaricides by obtaining limits of detection that range from 0.54 to 3.68 μg/L. The in situ solvent formation microextraction method possesses more positive characteristics than the ionic‐liquid‐assisted dispersive liquid–liquid microextraction method (except for spirodiclofen determination) when comparing the validation parameters. Both methods were successfully applied to determining acaricides in real water samples. 相似文献
13.
A copper(I)‐catalyzed tandem reaction of 2‐iodoanilines with isothiocyanates was achieved in hydrophobic [bmim][PF6] ionic liquid under mild conditions, generating a variety of 2‐aminobenzothiazoles in good to excellent yields. The tandem reaction that was carried out in [bmim][PF6] has some obvious advantages such as accelerated reaction rate and increased yield as compared with the reaction run in volatile solvents such as toluene. Furthermore, the CuI/1,10‐phenanthroline catalytic system can be reused up to eight times without loss of activity and efficiency. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
14.
Ionic Liquid‐Carbon Nanotube Modified Screen‐Printed Electrodes and Their Potential for Adsorptive Stripping Voltammetry
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Compared with paraffin oil, the use of ionic liquids as a binder in carbon paste type electrodes was shown to greatly enhance the accumulation of analytes, as illustrated with 17α‐ethynylestradiol as a model. The ionic “liquid” n‐octyl‐pyridinium hexafluorophosphate [C8py][PF6] was most efficient among several ionic liquids investigated. Such preconcentration allowed a [C8py][PF6]‐multiwalled carbon nanotubes (MWCNTs) (95 : 5 w/w) composite electrode to be useful for adsorptive stripping voltammetry. Screen‐printed electrodes modified with [C8py][PF6]‐MWCNTs were developed and were able to achieve high sensitivity during adsorptive stripping voltammetric measurements under optimised conditions. 相似文献
15.
d‐ Versus l‐Glucose Conjugation: Mitochondrial Targeting of a Light‐Activated Dual‐Mode‐of‐Action Ruthenium‐Based Anticancer Prodrug
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Lucien N. Lameijer Dr. Samantha L. Hopkins Tobias G. Brevé Sven H. C. Askes Dr. Sylvestre Bonnet 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(51):18484-18491
Light‐activated ruthenium polypyridyl anticancer prodrugs often suffer from poor water solubility, poor selectivity, and/or ill‐defined intracellular targets. Coordination of the d ‐ or l ‐glucose thioether ligand 3 (2‐(2‐(2‐(methylthio)ethoxy)ethoxy)ethyl‐β‐glucopyranoside) to the highly lipophilic ruthenium complex [Ru(tpy)(dppn)(H2O)]2+ ([ 1 ]2+; dppn=benzo[i]dipyrido‐[3,2‐a:2′,3′‐c]phenazine, tpy=2,2′:6′,2′′‐terpyridine) solved all these problems at once. The two enantiomers of [Ru(tpy)(dppn)( 3) ][PF6]2, [d ‐ 2 ][PF6]2 and [l ‐ 2 ][PF6]2, were soluble in water, which allowed the influence of the chirality of the glucose moiety on uptake, toxicity, and intracellular localization of the prodrug to be probed without changing any other physicochemical properties. Both compounds showed mild, but different, cytotoxicity in A549 (human lung carcinoma) and MCF‐7 (human breast adenocarcinoma) cancer cells in the dark, whereas following low doses of visible light irradiation (3.1 J cm?2 at λ = 454 nm), a similar, but high cytotoxicity (EC50 < 1 μm ), was observed. Irrespective of the chirality, both slightly emissive Ru complexes were found in the mitochondria, and two modes of action may contribute to light‐induced cell death: 1) the glucose thioether ligand is photosubstituted by water, thus [ 1 ]2+, which interacts with DNA at an exceptionally high 400:1 base pair/Ru ratio, is released; 2) both [ 1 ]2+ and [ 2 ]2+ produce massive amounts of singlet oxygen, which leads to very efficient photodynamic DNA cleavage. 相似文献
16.
Lijin Zhang Jinfu Liu Pingping Zhang Shijie Yan Xinyi He Fang Chen 《Chromatographia》2011,73(1-2):129-133
Hydrophilic ionic liquid of [BMIM][BF4] was successfully applied for the ultrasound-assisted extraction (UAE) of hydrophilic chlorogenic acid from Lonicera japonica Thunb. To explore this extraction procedure, the corresponding extraction parameters including the sample size, [BMIM][BF4] concentration, pH, extraction temperature, ultrasonic power and extraction time were investigated. The results revealed that the [BMIM][BF4]-based UAE efficiency of chlorogenic acid was higher than that of the ethanol-based UAE and the traditional refluent ethanol extraction. And the study on the method reliability further confirmed that the [BMIM][BF4]-based UAE is suitable for the effective extraction of chlorogenic acid from honeysuckle. 相似文献
17.
The Baylis–Hillman reaction is accelerated in the presence of ionic liquids. Of various 1‐butyl‐3‐methylimidazolium (bmim)‐based ionic liquids tested, [bmim][PF6] has been found to result in the highest rate increase. In the company of Lewis acid and H‐bond‐donor additives, the reaction rates further improve, albeit only modestly. A preparatively useful Baylis–Hillman procedure prescribes the use of [bmim][PF6] with La(OTf)3 and 2,2′2″‐nitrilotris[ethanol], in which the net effect of the ionic liquid is to bring about a more than twofold rate increase over the otherwise same reaction in MeCN. 相似文献
18.
Qingxiang Zhou Xiaoguo Zhang Guohong Xie Junping Xiao 《Journal of separation science》2009,32(22):3945-3950
This article describes a new, rapid and sensitive method for the determination of chlorotoluron, diethofencarb and chlorbenzuron from water samples with temperature‐controlled ionic liquid‐dispersive liquid‐phase microextraction. In the preconcentration procedure, ionic liquid 1‐hexyl‐3‐methylimidazolium hexafluorophosphate [C6MIM] [PF6] was employed as the extraction solvent. The parameters, such as volume of [C6MIM] [PF6], sample pH, extraction time, centrifuging time, temperature and salting‐out effect, were investigated in detail. Under the optimal extraction conditions, it has been found that three analytes had excellent LODs (S/N=3) in the range of 0.04–0.43 μg/L. The RSDs (n=6) were in the range of 1.3–4.7%. The proposed method was evaluated with lake water, tap water and melted snow water samples. The experimental results indicated that the proposed method had excellent prospect and would be widely used in the future. 相似文献
19.
Jun Li Jintao Zhang Zhengping Liu 《Journal of polymer science. Part A, Polymer chemistry》2006,44(15):4420-4427
Conventional free‐radical copolymerization of acrylonitrile (AN) and styrene (St) was realized in room temperature ionic liquids (RTILs), 1‐butyl‐3‐methylimidazolium tetrafluoroborate ([Bmim][BF4]) and 1‐butyl‐3‐methylimidazolium hexafluorophosphate ([Bmim][PF6]), under mild conditions. The copolymerization in RTILs was more rapid than that in traditional solvent DMF. Poly(styrene‐co‐acrylonitrile) (SAN) prepared in RTILs had higher molecular weight than that prepared in DMF or by bulk copolymerization. SAN with bimodal molecular weight distribution (MWD) were obtained in most of the reaction conditions in [Bmim][BF4] and some conditions in [Bmim][PF6]. By the analysis of reaction phenomena and fluorescence behavior, the reason of the difference in MWD could be attributed to the difference of reaction system compatibility mainly caused by the immiscibility of macromolecule with RTIL. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 4420–4427, 2006 相似文献
20.
Zhang‐Gao Le Zhen‐Chu Chen Yi Hu Qin‐Guo Zheng 《Journal of heterocyclic chemistry》2005,42(4):735-737
Phthalic anhydride reacts rapidly with Aromatic and aliphatic amines in ionic liquid [Bmim][PF6] or [Bmim][BF4] at 130 °C to give N‐aryl and N‐alkylphthalimides in excellent yields. 相似文献