Ionic liquid based dispersive liquid-liquid microextraction of aromatic amines in water samples

In this work, a new microextraction method termed ionic liquid based dispersive liquid-liquid microextraction （IL-DLLME） was demonstrated for the extraction of 2-methylaniline, 4-chloroaniline, 1-naphthylamine and 4-aminobiphenyl in aqueous matrices. After extraction the ionic liquid （IL） phase was injected directly into the high performance liquid chromatography （HPLC） system for determination. Some parameters that might affect the extraction efficiency were optimized. Under the optimum conditions, good linear relationship, sensitivity and reproducibility were obtained. The limits of detection （LOD, S/N = 3） for the four analytes were in the range of 0.45-2.6 μg L^-1. The relative standard deviations （R.S.D., n = 6） were in the range of 6.2-9.8%. This method was applied for the analysis of the real water samples. The recoveries ranged from 93.4 to 106.4%. The main advantages of the method are high speed, high recovery, good repeatability and volatile organic solvent-free.

Ternary System of Fe-based Ionic Liquid,Ethanol and Water for Wet Flue Gas Desulfurization

Fe-based ionic liquid （Fe-IL） was synthesized by mixing FeCl3·6H2O and 1-butyl-3-methylimidazolium chloride [Bmim]C1 in this paper. The phase diagram of a ternary Fe-IL, ethanol and water system was investigated to construct a ternary desulfurization solution for wet flue gas desulfurization. The effects of flow rate and concentration of SO2, reaction temperature, pH and Fe-IL fraction in aqueous desulfurization solution on the desulfiariza- tion efficiency were investigated. The results shows that the best composition of ternary desulfurization solution of Fe-IL, ethanol and water is 1 ： 1.5 ： 3 by volume ratio, and pH should be controlled at 2.0. Under such conditions, a desulfurization rate greater than 90% could be obtained. The product of sulfuric acid had inhibition effect on the wet desulfurization process. With applying this new ternary desulfurization solution, not only the catalyst Fe-IL can be recycled and reused, but also the product sulfuric acid can be separated directly from the ternary desulfurization system.

Asymmetric Reductive Amination of Carbonyl Compounds by Using<i>N,N,N</i>-Tributylpropanaminium Based Novel Chiral Ionic Liquid

Asymmetric reductive amination of carbonyl compounds was carried out using a novel class of aliphatic quarternary ammonium based chiral ionic liquid. S-(+)-2,3-dihydroxy-N,N,N-tributylpropanaminum bromide chiral ionic liquid has been synthesized, characterized and used for asymmetric reductive amination of carbonyl compounds in the presence of sodium borohydride. These preliminary results are encouraging and advocate dual role of novel ionic liquid as a medium and reducing agent for proficient conversion of ketones to amines, however, reductive amination reaction needs to be established for other substituents.

Facile Synthesis of Ureas in Ionic Liquid

The reaction of isocyanates with aliphatic and aromatic amines in the 1-n-butyl-3- methylimidazolium tetrafluoroborate (bmimBF4) ionic liquid in good to excellent yields is described. Due to its insolubility, the desired urea solids could be recovered by simple filtration from the ionic liquid after reaction.

Ionic liquid [bmim][BF_4] acts as solvent and promoter for synthesis of halo-containing N-arylphthalimides

A new synthetic process of N-arylphthalimide and halo-containing N-arylphthalimides through the reaction between phthalic anhydride and aromatic amines bearing halo groups in [bmim][BF4] was described, ionic liquid [bmim][BF4] acted as the dual role of solvent and promoter.

A Fast and Highly Efficient Protocol for Reductive Amination of Aromatic Aldehydes Using NaBH4 and Isoxazole Amines in an Ionic Liquid Medium

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.

Recent advances in carbon dioxide capture and utilization with amines and ionic liquids

Global warming and climate change due to anthropogenic carbon dioxide(CO_(2))have aroused significant concerns at the global scale due to rapid economic growth in industries and other fields.Therefore,CO_(2)capture,use,and storage have become particularly important.In this review,general background and methods for CO_(2)capture and separation,in particular,on ionic liquids(ILs)-based solvents and materials,are discussed.Comprehensive surveys of ILs for CO_(2)absorption are presented,which focused mainly on experimental researches,and then the concept is extended to functionalized absorbents and recent developments for CO_(2)capture.Major advantages and disadvantages of amines-based and ILs-based absorbents are discussed in this review.Solutions of traditional amines(MEA,MDEA,DEA,AMP,PZ,etc.)and ILs(conventional ILs,functionalized ILs,etc.)are summarized.Moreover,research progresses on CO_(2)separation are also introduced focusing mainly on amines and ILs-based membranes(e.g.supported amines membranes,SILMs).Futhermore,the fixation of CO_(2)into cyclic carbonates catalyzed by ILs(pure ILs,complex catalyst system with ILs,supported ILs,etc.)is summarized,clearly explaining the mechanism of CO_(2)fixation with ILs.Finally,exploration of some recent studies about CO_(2)capture and conversion by ILs and challenges for further progress are presented and related suggestions are put forward.

N-Protection of amines using pyridinium 2,2,2-trifluoroacetate ionic liquid as an efficient and reusable catalyst

A simple, green, and efficient method for the N-tert-butoxycarbonylation of amines by pyridinium 2,2,2- trifluoroacetate （[Py][OTf]） as an efficient and reusable catalyst is reported. In general, electron donating groups on aryl group give rise to the higher yields than electron withdrawing groups. Clean reaction, short reaction times, high yields, reusability of catalyst, and easy preparation of it are some advantages of this work.

天然气脱硫脱碳用离子液体的研究进展

目的对气田开采出的天然气采用离子液体进行脱硫脱碳处理,以期能达到GB 17820—2018《天然气》的要求。方法离子液体作为一种新型的绿色溶剂,其理化性质可通过阴、阳离子进行调控。通过对国内外学者相关文献进行梳理和归纳,对离子液体取代或补充天然气净化的传统吸收溶剂的潜力进行了探讨。结果离子液体净化工艺具有较好的酸气吸收效果,虽常规型与功能型离子液体的黏度高且价格昂贵,但复配胺类溶剂后可以有效减少或避免此类问题。结论综述了近年来离子液体吸收CO_(2)、H_(2)S的研究进展,可为其在天然气脱硫脱碳的应用提供有价值的参考。

功能化离子液体分离CO_(2)的研究现状及展望

离子液体以其优异的物理和化学稳定性、极低的蒸汽压、可调的结构特性及独特的物理化学性质,在气体分离领域展现出巨大的应用潜力,尤其在CO_(2)吸收方面效果显著。通过文献综述了离子液体在CO_(2)吸收领域的最新研究动态,着重探讨了氨基功能化离子液体、离子液体-水及离子液体-有机胺复配体系,以及离子液体相变吸收CO_(2)的机制与特性。同时,指出了当前研究面临的挑战与未来发展方向,旨在为气体分离技术的创新与应用提供新的启示。

离子液体-液相微萃取-高效液相色谱法测定纺织品中芳香胺

建立了一种基于1-丁基-3-甲基咪唑六氟磷酸盐离子液体的溶剂棒液相微萃取样品前处理技术，结合高效液相色谱法分析染色纺织品中源于禁用偶氮染料的8种致癌芳香胺的方法。考察了有机萃取溶剂、给出相pH值、搅拌速度、盐效应和萃取时间的影响，确定了以正辛醇为有机萃取溶剂，离子液体为接收相，给出相pH值为10并添加饱和NaCl溶液，搅拌速率为1000r／min，萃取时间为40min的芳香胺优化萃取条件。方法的线性范围宽，相关系数r〉0．9986；检出限为0．014～2．1μg／L（S／N=3）；相对标准偏差〈4．6％（n=10）；回收率为83．2％～91．2％；8种芳香胺的富集倍数在10～270倍之间。本法具有灵敏，萃取效率高，有机溶剂消耗少，操作简单、快捷等特点。

离子液体中钯配合物催化苯胺氧化羰化制苯氨基甲酸甲酯

使用含氮钯配合物为催化剂 ,离子液体为反应介质 ,高效地实现了苯胺羰化制苯氨基甲酸甲酯 .其中使用Pd (phen) 2 (PF6 ) 2 为催化剂 ,MeBuImBF4 为溶剂时其转化频率高于 80 0 0mol·mol- 1 ·h- 1 ,较使用离子液体以前提高了 5 7倍 .

离子液体中芳香醛选择性还原胺化反应研究

以离子液体为反应介质,对一系列还原胺化反应进行了研究。结果表明,经过缩合、还原两步连续反应,芳香醛与胺的产品收率在70%～98%,还原剂硼氢化钠在BMImBF4离子液体中对还原胺化反应表现出很好的还原能力和选择性,该合成反应条件温和,离子液体可稳定重复使用12次以上。

基于离子液体的液相微萃取技术对纺织品中22种致癌芳香胺的测定

采用以离子液体为萃取剂的液相微萃取，对纺织品检测国家标准方法（GB／T 17592—2006）中纺织品样品前处理方法进行了改进，建立了纺织品中源于偶氮染料的芳香胺的提取新方法。比较了直接浸入式微萃取和溶刺棒微萃取模式的萃取效果，确定以溶剂捧微萃取为微萃取模式。并优化了液相微萃取条件：以正辛醇为有机萃取溶剂，离子液体为接收相，给出相pH值为10并添加饱和NaCl溶液，搅拌速率为1000r／min，萃取时间为40min。参照纺织品检测国家标准方法，采用高效液相色谱法对所公布的22种致癌芳香胺进行了定性、定量测定。结果表明，该方法的线性范围宽，相关系数r〉0．9951，检出限（S／N=3）为0．01～2．13μg／L，相对标准偏差小于4．5％（n=8）；回收率为82％～94％，8种芳香胺的富集倍数为5．7～270．0。与纺织品检测国家标准方法相比，该方法简单、快速，并显示了较好的富集效果和高的回收率。

咪唑类[PF_6]^-型离子液体萃取胺类化合物

以咪唑类[PF6]-型离子液体1-丁基-3-甲基咪唑六氟磷酸盐([Bmim][PF6])、1-己基-3-甲基咪唑六氟磷酸盐([Hmim][PF6])和1-辛基-3-甲基咪唑六氟磷酸盐([Omim][PF6])对苯胺、对氯苯胺等7种胺类化合物的萃取,考察了溶液初始浓度、相比、盐类、pH及离子液体咪唑基团上取代烷基对萃取平衡的影响,并研究了萃取过程的热效应。实验结果表明:溶液初始浓度对分配系数影响较小;相比10∶1是离子液体对胺类化合物的溶解饱和临界点,当相比大于10∶1时,分配系数降低;NaCl、K2SO4可以增大萃取分配系数,ZnSO4对分配系数几乎没有影响;pH增加,分配系数增大;离子液体对不同取代基的胺类萃取能力有较大的差异,咪唑基团上取代烷基的长度对不同胺类物质的分配系数影响较显著;萃取过程属于焓增大的吸热过程。

离子液体萃取-高效液相色谱法测定食品接触材料中6种芳香胺的迁移量

提出了用高效液相色谱法测定食品接触材料中4,4'-二氨基二苯基甲烷、2,4-二甲基苯胺、4-氯邻甲苯胺、4-氨基联苯、3,3'-二氯联苯胺、4-氨基偶氮苯等6种芳香胺迁移量的测定方法。向样品的水浸泡液或乙酸(3+97)溶液浸泡液25.0 mL中加入离子液体[C_6mim][PF_6]0.652 3 g作为萃取剂,用磷酸盐缓冲溶液或氨水调至pH 8,加入氯化钠1.25 g,涡旋振荡萃取5 min,随后再离心5 min,下层离子液体相供高效液相色谱分析。用Diamonsil C_(18)色谱柱作固定相,流动相为水和乙腈混合溶液,于波长235 nm处进行检测。6种芳香胺的线性范围为0.02~2.0 mg·L^(-1),检出限(3S/N)在4.0~10.0μg·L^(-1)之间。方法用于尼龙勺样品分析,并以此为基体进行加标回收试验,测得回收率在91.6%~106%之间,测定值的相对标准偏差(n=5)在1.4%~8.8%之间。

硅胶担载离子液体催化剂的制备及其在由胺制二取代脲反应中的应用

采用溶胶 凝胶法制备了硅胶负载Rh(PPh3 ) 3 Cl 离子液体催化剂Rh DMImBF4/SiO2 gel,并对其催化胺类化合物氧化羰化制二取代脲反应的活性进行了考察 .结果表明 ,该催化体系对胺类化合物氧化羰化制二取代脲反应具有较高的催化活性 ,产物分离简单 ,催化剂易回收且具有较好的重复使用性能 .以氧为氧化剂时 ,苯胺转化率可达 95 % ,脲的选择性可达 98%以上 .以硝基苯为氧化剂时 ,苯胺转化率为 93% ,硝基苯转化率为 92 % ,脲的选择性为 98%以上 ,转化频率均超过 110 0 0mol/(mol·h) .此外 ,还制备了Co DMImBF4/SiO2 gel,Pd DMImBF4/SiO2 gel和Ru DMImBF4/SiO2 gel等催化剂 ,并对其催化氧化羰化胺类化合物的性能进行了考察 .

功能化离子液体[bmim]OTs催化乙酰化反应

以离子液体1-丁基-3-甲基咪唑四氟硼酸盐([bmim]BF4)为溶剂,对甲基苯磺酸根(OTs-)为阴离子的功能化离子液体[bmim]OTs为催化剂进行苯甲醇的乙酰化反应.结果表明,该体系循环使用10次后仍能保持良好的催化活性和稳定性,并对各种(伯、仲、叔)醇类、酚类和胺类化合物的乙酰化反应表现出良好的普适性.核磁共振波谱(13C NMR)分析结果表明,具有亲核性的[bmim]OTs和酰化试剂乙酸酐(Ac2O)形成的活性中间体AcOTs,是催化反应的活性物种.

咪唑键合硅胶固定相微柱液相色谱分离酚类和胺类化合物

由于微柱液相色谱(μ-LC)具有高检测灵敏度、低溶剂消耗、可以与质谱等多种检测器联用的优点,近年来受到广泛关注。将咪唑键合硅胶固定相填充到毛细管中,在自制的微柱液相色谱系统下利用此键合相具有的弱疏水作用,采用不同的流动相对酚类和胺类化合物进行了分离。结果表明,流动相中只需添加少量的有机溶剂就可以实现对一些有机化合物的分离,甚至可以只用纯水作流动相就能分离一些弱疏水性化合物,如酚类。微柱液相色谱的流动相用量少,避免或大大减少了对环境的污染。自制微柱液相色谱系统为下一步微柱液相色谱-质谱联用奠定了一定的基础。

氯铝酸离子液体催化合成十二烷基苯

用盐酸三乙胺和无水三氯化铝合成了不同配比的Et_3NHCl-xAlCl_3离子液体,研究了离子液体的组成、反应时间、反应温度、苯与离子液体的摩尔比、苯与1-十二烯摩尔比对苯与1-十二烯烷基化反应的影响。结果表明,Et_3NHCl-xAlCl_3酸性离子液体具有较高的催化活性,良好的低温反应活性和2位异构体选择性.通过正交试验,得到了优化的离子液体组成和反应条件为AlCl_3与Et_3NHCl的摩尔比1.4,反应温度10℃,苯与离子液体的摩尔比42,苯与1-十二烯摩尔比25。该条件下,1-十二烯的转化率为100%,2-苯基十二烷的选择性为42.5%.