A new nitrite ionic liquid (IL-ONO) as a nitrosonium source for the efficient diazotization of aniline derivatives and in-situ synthesis of azo dyes

A new task-specific nitrite containing ionic liquid derived from the O-nitrosation of N-methyl-N-hydroxybutylimidazolinium chloride was synthesized and used as a source of nitrosonium ion to affect the efficient diazotization of arylamines. The diazonium salts thus obtained were coupled, using standard experimental procedures, to a range of tertiary anilines, phenols and naphthols to afford the requisite azo dyes in good yield. The diazotization and subsequent azo-coupling generated the related azo dyes at 0-5 °C in short reaction times with a simple experimental procedure.     

离子液体超声辅助制备纳米CdSe及其荧光性能

采用离子液体超声辅助合成了CdSe纳米颗粒,用荧光分光光度计对纳米颗粒进行了表征。XRD结果显示,产物具有立方晶系结构,随着反应时间的增加,产物的结晶度逐渐提高。讨论了[Bmim]OH-H2O离子液体、反应时间对产物的形貌以及荧光性能的影响。在1 mL[Bmim]OH-H2O溶液中,超声反应1 h,所得产物的直径约为30～60 nm,荧光强度达到54 a.u.以上。离子液体在纳米颗粒表面形成一种保护膜,有效地阻止了颗粒间的团聚,提高了产物的荧光性能。     

Biphasic Hydrogenation of Olefins by Functionalized Ionic Liquid‐Stabilized Palladium Nanoparticles

Palladium nanoparticles in the size range of 5–6 nm were prepared conveniently by reducing palladium(II) with atmospheric pressure hydrogen and stabilized by 2,2′‐dipyridylamine‐functionalized imidazolium cations according to our approach. The efficient catalytic conversion of cyclohexene into cyclohexane by the functionalized ionic liquid‐stabilized palladium nanoparticles has been performed under very mild hydrogen pressure (0.1 MPa) and at 35 °C. It was found that the concentration of palladium and the reaction temperature considerably affected the size and degree of aggregation of Pd nanoparticles in ionic liquid, which further changed the performance of the catalyst activity. The synthesized nanocatalysts can be recycled at least five times without any loss of the activity. Finally, the scope of substrates was also investigated. The excellent catalytic activity of the present system can be attributed to good stabilization and high dispersion of palladium nanoparticles.     

The functionalized ionic liquid-stabilized palladium nanoparticles catalyzed selective hydrogenation in ionic liquid

The functionalized ionic liquid (2,3-dimethyl-1-[3-N,N-bis(2-pyridyl)-propylamido] imidazolium hexafluorophosphate, [BMMDPA][PF₆]) stabilized and modified palladium nanoparticles were obtained by reducing palladium(II) complex with molecular hydrogen. The as-synthesized palladium nanoparticles have been characterized by different methods. It was demonstrated that the Pd nanoparticles were very efficient catalysts for the selective hydrogenation of the CC bonds of various functionalized alkenes under mild conditions in neat ionic liquid (1-n-butyl-2,3-dimethylimidazolium hexafluorophosphate, [BMMIM][PF₆]). An efficient separation of the products from reaction mixture (ionic liquid phase) was realized and the catalyst’s nano-dispersion and high performance could be preserved.     

室温离子液体[BMIm]PF_6中纳米银的制备及结构表征

在微波条件下合成了1-丁基-3-甲基咪唑六氟磷酸盐([BMIm]PF6)离子液体,用红外光谱对其结构进行了表征。用该离子液体作为反应介质,采用硼氢化钠为还原剂制备了金属银纳米微粒,用X射线衍射、扫描电子显微镜、傅立叶红外光谱和热分析对纳米银的结构和形貌进行了表征。结果表明,所制备的纳米银具有立方相结构,粒径约为10 nm;离子液体不但作为反应的溶剂而且还作为修饰剂,包覆在银纳米微粒的表面,从而阻止了银纳米微粒的团聚。     

Poly(ionic liquid) nanoparticles as novel colloidal template for silica nanocasting

Spherical poly(ionic liquid) (PIL) nanoparticles of different size (25–70 nm) were synthesized and applied as a novel colloidal soft template for the preparation of meso- and macroporous inorganics, here exemplified with silica and its metal nanoparticle doping via nanocasting. Pore size and pore architecture can be adjusted by appropriate choice of the template and the reaction conditions. Unexpectedly, it was found that the in situ generated methanol plays a very important role during the casting process. It enlarged the overall surface area by introducing a significant fraction of micropores and small mesopores. The largest specific surface area was obtained at an optimized ratio of tetramethyl orthosilicate (TMOS) to PIL nanoparticle. In addition, PIL nanoparticles pre-functionalized with Pt metal nanoparticles were used in the same manner as hybrid templates for nanocasting. The pyrolysis conditions were optimized to synthesize mesoporous silica functionalized with uniformly distributed metal nanoparticles of very small size in a one-pot process.     

离子液体催化大豆油制备生物柴油

制备了对水稳定性好、带—SO₃H官能团的咪唑丙烷磺酸硫酸氢盐离子液体，并以其作为催化剂进行了大豆油酯交换反应制备生物柴油的研究。考察了离子液体的用量、醇与油物质的量比、反应温度和反应时间对酯交换反应的影响及离子液体的稳定性。实验结果表明，在n(甲醇)∶n(大豆油) =12∶1、反应温度120 ℃、反应时间8 h和催化剂用量为原料油质量的4.0%条件下,产物中脂肪酸甲酯收率可达96.5%,且离子液体的稳定性好,可循环使用。     

己内酰胺苯磺酸类离子液体催化甲苯选择性硝化反应的研究

制备了己内酰胺对甲基苯磺酸和苯磺酸离子液体作为催化剂和溶剂,用于催化甲苯与等摩尔67%(m/m)硝酸的硝化反应,并用1H NMR进行了表征。研究了不同的反应温度、时间和离子液体用量及不同的离子液体等因素对甲苯硝化反应的影响。结果表明:该离子液体对甲苯的硝化有较好的对位选择性,产物中邻、对异构体质量比为1.2,较硝硫混酸硝化(邻、对异构体质量比约2.0)显著降低,收率可达37.1%,且可重复使用。     

离子液体[bmim]PTSA中松香乙酯的微波辅助合成

以1-正丁基-3-甲基咪唑对甲苯磺酸盐离子液体([bmim]PTSA)作溶剂和催化剂,在微波辐射下通过松香与乙醇的直接酯化反应合成了松香乙酯。探索了催化剂种类、离子液体种类、离子液体用量、反应温度、反应时间等因素对反应酯化率的影响,确定最佳反应条件为:反应温度100℃,反应时间1 h,[bmim]PTSA对松香质量比4∶1。在此条件下,酯化率达95.5%。该离子液体易于与反应产物分离,且可以重复使用。     

在[BMIM][PF_6]离子液中外消旋DL-薄荷醇催化手性选择性酯化

在疏水性离子液体1-丁基-3-甲基咪唑六氟磷酸盐([BMIM][PF6])和正己烷介质中分别进行了酯酶Candida rugosa催化外消旋(DL)-薄荷醇的手性选择性酯化反应。试验结果表明,[BMIM][PF6]中的酯化反应速率,酯化转化率和手性选择性都优于正己烷。当加酶量大于130 U/mL时,离子液体中的酯化反应在2~8 h范围内出现最大转化率;在正己烷中,酶用量在67~167 U/mL范围内,其酯化转化率也随时间呈逐渐上升,无极值出现。另外,在离子液体中,水含量的增加在一定程度上可以增大酯化手性选择性,但反应速率会被降低。     

功能化酸性离子液体催化合成氯乙酸异丙酯的研究

研究了功能化酸性离子液体催化合成氯乙酸异丙酯的反应,考察了不同离子液体、反应温度、反应时间和离子液体与反应物物质的量比［n(离子液体)∶n（反应物）］等对反应的影响。结果表明,以离子液体N-(4-磺酸基丁基)吡啶硫酸氢盐｛［(CH2)4SO3HPy］HSO4｝为催化剂,在60 ℃、n(离子液体)∶n（反应物）=1∶5,反应4 h后,反应的转化率和选择性分别为91%和100%。催化剂循环使用5次,催化活性不变。     

Ionic Liquid‐Promoted Oxidant‐Free Dehydrogenation of Alcohols with Water‐Soluble Ruthenium Nanoparticles in Aqueous Phase

An oxidant‐free dehydrogenation of alcohols in the aqueous phase was developed for the first time using water‐soluble poly(N‐vinyl‐2‐pyrrolidone) (PVP)‐stabilized ruthenium nanoparticles with an ionic liquid as a promoter. The present catalytic system was highly efficient and stable for the catalytic dehydrogenation of various alcohols. It was found that the basic ionic liquid 1‐n‐butyl‐2,3‐dimethylimidazolium acetate ([BMMIM] OAc) additive played a crucial role in enhancing the catalytic activity and stability of ruthenium(0) nanoparticles. A reaction kinetics study and ¹H NMR analysis demonstrated that the basic ionic liquid and ruthenium nanoparticles exerted a synergetic effect for the dehydrogenation reaction.     

Polyethylene glycol-supported ionic liquid as a highly efficient catalyst for the synthesis of propylene carbonate under mild conditions

The coupling reaction of propylene and CO₂ to form propylene carbonate (PC) was promoted by an ionic liquid (IL) covalently bound to polyethylene glycol (PEG). The supported ionic liquid, which has both acidic and basic components, proved to be an active catalyst for PC synthesis under mild conditions. The effects of different cations and anions, reaction temperature, CO₂ pressure, and reaction time were investigated. It was demonstrated that the acid group in the catalyst plays an important role in the reaction. With this system, a high PC yield (95%) was achieved under mild conditions (3.0 MPa, 120°C and 4 h) without a co-solvent. In addition, the catalyst was readily recovered and reused. Based on the experimental results, a plausible mechanism for the catalyst was proposed.     

离子液体在生物柴油合成中的应用研究进展

离子液体具有较强的催化能力、较强的溶解能力、较低的蒸气压等特性,其在生物柴油合成中的应用近年来受到人们的持续关注。本文介绍了离子液体不仅可作为酶催化合成生物柴油的绿色溶剂,作为酯交换反应合成生物柴油的催化剂,还可作为催化剂载体,并可以实现离子液体在生物合成应用中的循环利用。提出了今后应加强对离子液体中固定化脂肪酶催化合成生物柴油的传质过程和催化作用机制及离子液体的循环利用进行研究。     

普通离子液体和功能化离子液体的合成研究进展

离子液体是在室温下为液体、具有离子特性的新型绿色溶剂,作为一类环境友好型的反应介质,在诸多领域有其独特的性质.综述了普通离子液体和功能化离子液体的合成研究进展,并对其前景进行了展望.     

离子液体在精细化工中的应用

综述了离子液体在Heck反应、氧化反应、加氢还原反应、傅-克反应和醇的卤代反应中的应用。氯铝酸离子液体催化的合成丁基苯的傅-克反应中,室温下反应3m in即可反应完全,而在离子液体中进行的烯烃加氢反应只需反应6h。离子液体也能加快氧化反应的反应速度。     

离子液体在回收模拟粗苯中噻吩的研究

为回收焦化粗苯中的噻吩,采用等物质的量的磷酸三甲酯和N-甲基咪唑反应合成离子液体,以该离子液体为萃取剂萃取脱除粗苯模拟液中的噻吩,并通过再生离子液体的方法回收噻吩.实验考察了萃取时间、萃取温度、离子液体与粗苯模拟液的体积比以及离子液体的重复使用性能等对噻吩脱除效率的影响,同时对萃取后离子液体中噻吩的回收也做了相应的探讨...     

废旧光盘在离子液体中的甲醇醇解反应

以离子液体［Bmim］［Cl］为反应介质和催化剂,对废旧光盘的甲醇醇解反应进行了研究。考察了反应温度、反应时间、催化剂用量、甲醇用量对醇解反应结果的影响,得到的较佳醇解反应条件为反应温度110℃,反应时间1.5 h,n(甲醇)∶n(光盘)=8∶1,m(［Bmim］［Cl］)∶m(光盘)=1∶1,在上述条件下,光盘醇解率≥98%,双酚A收率≥93%。对离子液体的回用性能进行了考察,结果表明,离子液体回用8次后光盘的醇解率和BPA的收率无明显变化。采用FT-IR技术对醇解产物进行了表征。     

离子液体在Aldol反应中的应用

综述了离子液体在羟醛缩合(Aldol)反应中的应用。离子液体不仅可以提高反应收率,而且通过选择离子液体/催化剂体系,可以定向的得到预期的Aldol产物。     

氯铝酸盐离子液体催化苯与十二烯烷基化反应

针对酸性氯铝酸盐室温离子液体[BMIM][AlCl4]催化苯与1-十二烯烷基化合成十二烷基苯反应体系的物理化学特性,设计了一套可以分别进行间歇和连续操作的连续流动搅拌反应装置。间歇操作的反应结果表明．[BMIM][AlCl4]催化剂体系的总体结果优于传统催化剂无水AlCl3和氢氟酸,催化剂的用量和反应温度可以大大降低,2-苯基异构体的选择性较高。在连续操作条件下,一定的流量范围内实现了离子液体催化剂和反应料液的原位分离,催化剂被有效地局限在反应区域,并因在运转过程中始终未暴露从而得到了比间歇操作更加稳定和高效的反应结果。