We gratefully acknowledge the Swedish Research Council Formas for generous financial support.

甲基-6-氧代-3,4,6- triphenylhexanoate 1.革兰氏规模合成<ol><li>干1-乙基-3-甲基咪唑鎓乙酸盐（EMIMAc）在10毫巴，40℃下1小时，在旋转蒸发器的圆底烧瓶中。 </li><li>添加2.1克干燥EMIMAc和1.0克1,3-二苯基-2-丙烯-1-酮向100毫升圆底烧瓶配备有磁力搅拌器。 </li><li>添加2.019毫升甲醇和2.3克肉桂烧瓶中。 </li><li>在室温（22℃）搅拌1分钟溶解在60毫升二氯甲烷的混合物中。 </li><li>接着添加0.37 ml的1.8二氮杂二环[5.4.0]十一-7-烯（DBU）到搅拌的混合物（步骤1.4）和帽的圆底烧瓶中。 </li><li>搅拌，在500rpm在室温（22℃）的速度一磁力搅拌棒。 </li><li>检查用 1 H-NMR。24查找在7.8 ppm的区域中的查耳酮的双键消失反应完成。 </li><li>当该反应达到<html>完成除去挥发旋转蒸发器上在10毫巴，20℃下进行15分钟。 </li><li>加入50毫升甲醇向残余物通过有磁性搅拌棒搅拌以溶解EMIMAc。 </li><li>通过用磁力搅拌棒搅拌下剧烈在750 rpm的速度为30分钟，除去从烧瓶壁上的固体。如果有必要，用刮刀从墙上去除剩余的固体。 </li><li>过滤器玻璃料（孔径3）的混合物。 </li><li>用另外20ml甲醇洗。如果回收EMIMAc的期望蒸发甲醇滤液。 （步骤2.1）。 </li><li>仍然在玻璃料上，轻轻地划分滤饼（从步骤1.11）成较小的块用刮勺和经由粉末漏斗转移到固体预称重的圆底烧瓶中，并在真空下干燥固体。 </li><li>称量烧瓶并计算产率。 </li><li>由1 H NMR（步骤1.7）分析产物。有报道光谱进行比较。24 </li></ol>EMIMAc的标题“&gt; 2。循环<ol><li>在10毫巴减压除去从甲醇混合物（来自步骤1.12）挥发物，在40℃下30分钟。 </li><li> 通过 1 H NMR和13 C-NMR分析所得的油，以检查EMIMAc存在。24 </li><li>使用回收EMIMAc从步骤1.2开始。 </li></ol> 3.凝胶<ol><li>储备溶液的制备<ol><li>加入200毫克甲基-6-氧代-3,4,6- triphenylhexanoate（从步骤1.15的产物）和磁搅拌棒至小瓶的。加入2.0毫升二氯甲烷中，以溶解酮酯。搅拌，直到一切都已经解散。 </li></ol></li><li>凝胶<ol><li>加入50毫升庚烷，以500毫升烧杯中。添加1.5 ml的储备溶液的庚烷。搅拌迅速，以确保充分混合，静置而不直至凝胶化发生在环境温度下搅拌。 </li></ol></li></ol>

<ol>
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The authors have nothing to disclose.

基于由酮酯3的X射线分析和对所提出的Bode和同事30的机械调查确定反 -构型的下述反应路径建议（图5）。白细胞介素脱质子产生NHC种;所述NHC反应与不饱和醛形成布瑞斯罗夫中间体I中布瑞斯罗夫中间和在跨安息香反应的查耳酮反应形成二烯二。中级II经过转乘船过渡态（TS）的氧Cope重排，设置防取向的手性中心III。互变异构之后，酰基氮鎓IV与甲醇反应来交付产品?...

<img alt="TOC 1" src="/files/ftp_upload/53213/53213TOC.jpg" /> （以上）的1,6-酮酯三组分合成：一类新的低分子量胶凝剂。 离子液体（离子液体）具有高稳定性，低挥发性，不可燃性，并因此呈现关注，因为安全的反应介质和理想的溶剂进行回收。1-3二烷基咪唑鎓是一个特定类型的离子液体，在碱的存在下可以去质子化，以使一个N-杂环卡宾（NHC）。4在有机催化的领域中，的NHCs，根据不同的反应路径操作时，已经被广泛的使用在广泛的通用反应。5-11 尽管如此，ILS和CC键formin之间的连接摹NHC催化相对未开发的。尽管如此，从的NHCs离子液体衍生已经报道了催化CC键形成反应，如苯偶姻缩合和施德达反应。12-22。例如，Davis等人已经表明，从N-烷基thiazoliums衍生离子液体作为在预催化剂形成苯甲醛安息香12 最近，Chen和同事扩展使用基于IL咪唑这个概念，1-乙基-3-甲基咪唑鎓乙酸盐（EMIMAc），对5-羟甲基糠醛（HMF）执行安息香缩合以生成5,5&#39; -二（羟甲基）furoin（DHMF）。23由于离子液体可以买到，报价产生NHC的的一种廉价的方式，我们有兴趣在研究什么其他类型的反应，离子液体可以执行。为此，我们发现，二烷基咪唑鎓可有效用作在正规共轭additi预催化剂上的不饱和醛以查耳酮（图1），得到1,6-酮酯。最有效的IL，EMIMAc，促进肉桂醛和查尔之间的高立体选择性反应。发生反应以高偏爱反 -非对映和1,6-酮酯可以分离在产率高达92％。24,25,26 <img alt="图1" src="/files/ftp_upload/53213/53213fig1.jpg" /> 图1：IL-介导的三组分，立体选择性加成肉桂醛以查耳酮。

<table>
	<tbody>
		<tr>
			<td>1-ethyl-3-methyl imidazolium acetate</td>
			<td>Aldrich</td>
			<td>51053-100G-F</td>
			<td>Produced by BASF &#8805;90%, dried on a rotary evaporated before use (10 mBar, 40 &#176;C, 1h) 
			CAS NUMBER: 143314-17-4</td>
		</tr>
		<tr>
			<td>1,3-diphenyl-2-propen-1-one</td>
			<td>Aldrich</td>
			<td>11970-100G</td>
			<td>98.0% 
			CAS NUMBER: 94-41-7</td>
		</tr>
		<tr>
			<td>trans-cinnamaldehyde&#160;</td>
			<td>Aldrich</td>
			<td>C80687-25G</td>
			<td>99%, stored under nitrogen prior to use 
			CAS NUMBER: 14371-10-9</td>
		</tr>
		<tr>
			<td>1,8-Diazobicyclo[5.4.0]undec-7-ene</td>
			<td>Aldrich</td>
			<td>139009-25G</td>
			<td>98% 
			CAS NUMBER: 6674-22-2</td>
		</tr>
		<tr>
			<td>Methanol</td>
			<td>Sigma-Aldrich</td>
			<td>32213N-2.5L</td>
			<td>puriss. P.a., ACS reagent, reag. ISO, reag. Ph. Eur. &#8805;99.8% (GC) 
			CAS NUMBER: 67-56-1</td>
		</tr>
		<tr>
			<td>Dichloromethane</td>
			<td>Fischer Chemical</td>
			<td>D/1852/17X</td>
			<td>Analytic reagent grade, stabilized with amylene 
			CAS NUMBER:9/2/1975</td>
		</tr>
		<tr>
			<td>n-Heptane</td>
			<td>Fischer Chemical</td>
			<td>H/0160/17X</td>
			<td>Analytic reagent grade 
			CAS NUMBER: 142-82-5</td>
		</tr>
	</tbody>
</table>

highly stereoselective synthesis of 1,6-ketoesters mediated by ionic liquids: a three-component reaction enabling rapid access to a new class of low molecular weight gelators

In organic chemistry ionic liquids (ILs) have emerged as safe and recyclable reaction solvents. In the presence of a base ILs can be deprotonated to form catalytically active N-Heterocyclic Carbenes (NHCs). Here we have used ILs as precatalysts in the addition of &#945;,&#946;-unsaturated aldehydes to chalcones to form 1,6-ketoesters, incorporating an anti-diphenyl moiety in a highly stereoselective fashion. The reaction has a broad substrate scope and several functional groups and heteroaromatics can be integrated into the ketoester backbone in generally good yields with maintained stereoselectivity. The reaction protocol is robust and scalable. The starting materials are inexpensive and the products can be obtained after simple filtration, avoiding solvent-demanding chromatography. Furthermore, the IL can be recycled up to 5 times without any loss of reactivity. Moreover, the 1,6-ketoester end product is a potent gelator in several hydrocarbon based solvents. The method enables rapid access to and evaluation of a new class of low molecular weight gelators (LMWGs) from recyclable and inexpensive starting materials.

如上述例举EMIMAc充当在正规共轭加成α，β不饱和醛与查耳酮一个前段催化剂。其它市售咪唑鎓基的离子液体，例如1-乙基-3-甲基咪唑氯化物（EMIMCl）和1-丁基-3-甲基咪唑氯化物（BMIMCl）也进行了研究，然而，这些反应进行较低的产率，表明乙酸根阴离子可以是为反应性（ 表1，进入1-3）很重要。27,28 * *阴离子该反应中的作用是在目前还不清楚?...

Watch this Scientific Journal Video about Highly Stereoselective Synthesis of 1,6-Ketoesters Mediated by Ionic Liquids: A Three-component Reaction Enabling Rapid Access to a New Class of Low Molecular

Highly Stereoselective Synthesis of 1,6-Ketoesters Mediated by Ionic Liquids: A Three-component Reaction Enabling Rapid Access to a New Class of Low Molecular Weight Gelators

Ionic liquids (ILs) mediate fast, simple and cheap access to 1,6-ketoesters in high diastereoselectivities and good yields. The reaction protocol is robust and the 1,6-ketoesters can be obtained in gram scale after a simple filtration protocol. Moreover, the 1,6-ketoesters are potent gelators in hydrocarbon solvents.

1,6-酮酯高立体选择性合成离子液体介导：三组分反应启用快速进入低分子量胶凝剂的新型类

In organic chemistry ionic liquids (ILs) have emerged as safe and recyclable reaction solvents. In the presence of a base ILs can be deprotonated to form ...

highly-stereoselective-synthesis-16-ketoesters-mediated-ionic-liquids

Research

JoVE Journal

Chemistry

8.6K 次观看.  Chalmers University of Technology. Ionic liquids (ILs) mediate fast, simple and cheap access to 1,6-ketoesters in high diastereoselectivities and good yields. The reaction protocol is robust and the 1,6-ketoesters can be obtained in gram scale after a simple filtration protocol. Moreover, the 1,6-ketoesters are potent gelators in hydrocarbon solvents. 

视频: Highly Stereoselective Synthesis of 1,6-Ketoesters Mediated by Ionic Liquids: A Three-component Reaction Enabling Rapid Access to a New Class of Low Molecular Weight Gelators

Preparation and Use of Samarium Diiodide (SmI2) in Organic Synthesis: The Mechanistic Role of HMPA and Ni(II) Salts in the Samarium Barbier Reaction

Although initially considered an esoteric reagent, SmI2 has become a common tool for synthetic organic chemists. SmI2 is generated through the addition of molecular iodine to samarium metal in THF.1,2-3 It is a mild and selective single electron reductant and its versatility is a result of its ability to initiate a wide range of reductions including C-C bond-forming and cascade or sequential reactions. SmI2 can reduce a variety of functional groups including sulfoxides and sulfones, phosphine oxides, epoxides, alkyl and aryl halides, carbonyls, and conjugated double bonds.2-12 One of the fascinating features of SmI-2-mediated reactions is the ability to manipulate the outcome of reactions through the selective use of cosolvents or additives. In most instances, additives are essential in controlling the rate of reduction and the chemo- or stereoselectivity of reactions.13-14 Additives commonly utilized to fine tune the reactivity of SmI2 can be classified into three major groups: (1) Lewis bases (HMPA, other electron-donor ligands, chelating ethers, etc.), (2) proton sources (alcohols, water etc.), and (3) inorganic additives (Ni(acac)2, FeCl3, etc).3
Understanding the mechanism of SmI2 reactions and the role of the additives enables utilization of the full potential of the reagent in organic synthesis. The Sm-Barbier reaction is chosen to illustrate the synthetic importance and mechanistic role of two common additives: HMPA and Ni(II) in this reaction. The Sm-Barbier reaction is similar to the traditional Grignard reaction with the only difference being that the alkyl halide, carbonyl, and Sm reductant are mixed simultaneously in one pot.1,15 Examples of Sm-mediated Barbier reactions with a range of coupling partners have been reported,1,3,7,10,12 and have been utilized in key steps of the synthesis of large natural products.16,17 Previous studies on the effect of additives on SmI2 reactions have shown that HMPA enhances the reduction potential of SmI2 by coordinating to the samarium metal center, producing a more powerful,13-14,18 sterically encumbered reductant19-21 and in some cases playing an integral role in post electron-transfer steps facilitating subsequent bond-forming events.22 In the Sm-Barbier reaction, HMPA has been shown to additionally activate the alkyl halide by forming a complex in a pre-equilibrium step.23
Ni(II) salts are a catalytic additive used frequently in Sm-mediated transformations.24-27 Though critical for success, the mechanistic role of Ni(II) was not known in these reactions. Recently it has been shown that SmI2 reduces Ni(II) to Ni(0), and the reaction is then carried out through organometallic Ni(0) chemistry.28
These mechanistic studies highlight that although the same Barbier product is obtained, the use of different additives in the SmI2 reaction drastically alters the mechanistic pathway of the reaction. The protocol for running these SmI2-initiated reactions is described.

Preparation and Use of Samarium Diiodide SmI2 in Organic Synthesis: The Mechanistic Role of HMPA and NiII Salts in the Samarium Barbier Reaction

A straightforward procedure for the preparation of samarium diiodide (SmI2) in THF is described. The role of two main additives namely hexamethylphosphoramide (HMPA) and Ni(acac)2 in Sm mediated reactions is demonstrated in the Sm-Barbier reaction.

二碘化钐的制备和使用（SMI<sub&gt; 2</sub&gt;）在有机合成中：HMPA和镍（II）盐的钐巴尔比耶反应的机理作用

Although initially considered an esoteric reagent, SmI2 has become a common tool for synthetic organic chemists. SmI2 is generated through the addition of ...

科研

化学

Synthesis and Reaction Chemistry of Nanosize Monosodium Titanate

This paper describes the synthesis and peroxide-modification of nanosize monosodium titanate (nMST), along with an ion-exchange reaction to load the material with Au(III) ions. The synthesis method was derived from a sol-gel process used to produce micron-sized monosodium titanate (MST), with several key modifications, including altering reagent concentrations, omitting a particle seed step, and introducing a non-ionic surfactant to facilitate control of particle formation and growth. The resultant nMST material exhibits spherical-shaped particle morphology with a monodisperse distribution of particle diameters in the range from 100 to 150&#160;nm. The nMST material was found to have a Brunauer-Emmett-Teller (BET) surface area of 285 m2g-1, which is more than an order of magnitude higher than the micron-sized MST. The isoelectric point of the nMST measured 3.34 pH units, which is a pH unit lower than that measured for the micron-size MST. The nMST material was found to serve as an effective ion exchanger under weakly acidic conditions for the preparation of an Au(III)-exchange nanotitanate. In addition, the formation of the corresponding peroxotitanate was demonstrated by reaction of the nMST with hydrogen peroxide.

The surfactant mediated sol-gel synthesis of nanosized monosodium titanate is described, along with preparation of the corresponding peroxide modified material. An ion-exchange reaction with Au(III) is also presented.

纳米尺寸钛酸二氢钠的合成和化学反应

This paper describes the synthesis and peroxide-modification of nanosize monosodium titanate (nMST), along with an ion-exchange reaction to load the ...

Synthesis and Exfoliation of Discotic Zirconium Phosphates to Obtain Colloidal Liquid Crystals

Due to their abundance in natural clay and potential applications in advanced materials, discotic nanoparticles are of interest to scientists and engineers. Growth of such anisotropic nanocrystals through a simple chemical method is a challenging task. In this study, we fabricate discotic nanodisks of zirconium phosphate [Zr(HPO4)2&#183;H2O] as a model material using hydrothermal, reflux and microwave-assisted methods. Growth of crystals is controlled by duration time, temperature, and concentration of reacting species. The novelty of the adopted methods is that discotic crystals of size ranging from hundred nanometers to few micrometers can be obtained while keeping the polydispersity well within control. The layered discotic crystals are converted to monolayers by exfoliation with tetra-(n)-butyl ammonium hydroxide [(C4H9)4NOH, TBAOH]. Exfoliated disks show isotropic and nematic liquid crystal phases. Size and polydispersity of disk suspensions is highly important in deciding their phase behavior.

A two dimensional model material of discotic zirconium phosphate was developed. The inorganic crystal with lamellar structure was synthesized by hydrothermal, reflux, and microwave-assisted methods. On exfoliation with organic molecules, layered crystals can be converted to monolayers, and nematic liquid crystal phase was formed at sufficient concentration of monolayers.

合成与盘状磷酸盐锆剥落获取胶体液晶

Due to their abundance in natural clay and potential applications in advanced materials, discotic nanoparticles are of interest to scientists and ...

Synthesis of Programmable Main-chain Liquid-crystalline Elastomers Using a Two-stage Thiol-acrylate Reaction

This study presents a novel two-stage thiol-acrylate Michael addition-photopolymerization (TAMAP) reaction to prepare main-chain liquid-crystalline elastomers (LCEs) with facile control over network structure and programming of an aligned monodomain. Tailored LCE networks were synthesized using routine mixing of commercially available starting materials and pouring monomer solutions into molds to cure. An initial polydomain LCE network is formed via a self-limiting thiol-acrylate Michael-addition reaction. Strain-to-failure and glass transition behavior were investigated as a function of crosslinking monomer, pentaerythritol tetrakis(3-mercaptopropionate) (PETMP). An example non-stoichiometric system of 15 mol% PETMP thiol groups and an excess of 15 mol% acrylate groups was used to demonstrate the robust nature of the material. The LCE formed an aligned and transparent monodomain when stretched, with a maximum failure strain over 600%. Stretched LCE samples were able to demonstrate both stress-driven thermal actuation when held under a constant bias stress or the shape-memory effect when stretched and unloaded. A permanently programmed monodomain was achieved via a second-stage photopolymerization reaction of the excess acrylate groups when the sample was in the stretched state. LCE samples were photo-cured and programmed at 100%, 200%, 300%, and 400% strain, with all samples demonstrating over 90% shape fixity when unloaded. The magnitude of total stress-free actuation increased from 35% to 115% with increased programming strain. Overall, the two-stage TAMAP methodology is presented as a powerful tool to prepare main-chain LCE systems and explore structure-property-performance relationships in these fascinating stimuli-sensitive materials.

A novel methodology is presented to synthesize and program main-chain liquid-crystalline elastomers using commercially available starting monomers. A wide range of thermomechanical properties was tailored by adjusting the amount of crosslinker, while the actuation performance was dependent on the amount of applied strain during programming.

的可编程主链液晶性弹性体用双级硫醇丙烯酸酯反应合成

This study presents a novel two-stage thiol-acrylate Michael addition-photopolymerization (TAMAP) reaction to prepare main-chain liquid-crystalline ...

Synthesis of Cd-free InP/ZnS Quantum Dots Suitable for Biomedical Applications

Fluorescent nanocrystals, specifically quantum dots, have been a useful tool for many biomedical applications. For successful use in biological systems, quantum dots should be highly fluorescent and small/monodisperse in size. While commonly used cadmium-based quantum dots possess these qualities, they are potentially toxic due to the possible release of Cd2+ ions through nanoparticle degradation. Indium-based quantum dots, specifically InP/ZnS, have recently been explored as a viable alternative to cadmium-based quantum dots due to their relatively similar fluorescence characteristics and size. The synthesis presented here uses standard hot-injection techniques for effective nanoparticle growth; however, nanoparticle properties such as size, emission wavelength, and emission intensity can drastically change due to small changes in the reaction conditions. Therefore, reaction conditions such temperature, reaction duration, and precursor concentration should be maintained precisely to yield reproducible products. Because quantum dots are not inherently soluble in aqueous solutions, they must also undergo surface modification to impart solubility in water. In this protocol, an amphiphilic polymer is used to interact with both hydrophobic ligands on the quantum dot surface and bulk solvent water molecules. Here, a detailed protocol is provided for the synthesis of highly fluorescent InP/ZnS quantum dots that are suitable for use in biomedical applications.

In this protocol, the synthesis of Cd-free InP/ZnS quantum dots (QDs) is detailed. InP-based QDs are gaining popularity due to the toxicity of Cd2+ ions that may be released through nanoparticle degradation. After synthesis, QDs are solubilized in water using an amphiphilic polymer for use in biomedical applications.

镉免费的InP /硫化锌量子点的合成适合生物医学应用

Fluorescent nanocrystals, specifically quantum dots, have been a useful tool for many biomedical applications. For successful use in biological systems, ...

Facile Synthesis of Worm-like Micelles by Visible Light Mediated Dispersion Polymerization Using Photoredox Catalyst

Presented herein is a protocol for the facile synthesis of worm-like micelles by visible light mediated dispersion polymerization. This approach begins with the synthesis of a hydrophilic poly(oligo(ethylene glycol) methyl ether methacrylate) (POEGMA) homopolymer using reversible addition-fragmentation chain-transfer (RAFT) polymerization. Under mild visible light irradiation (&#955; = 460 nm, 0.7 mW/cm2), this macro-chain transfer agent (macro-CTA) in the presence of a ruthenium based photoredox catalyst, Ru(bpy)3Cl2 can be chain extended with a second monomer to form a well-defined block copolymer in a process known as Photoinduced Electron Transfer RAFT (PET-RAFT). When PET-RAFT is used to chain extend POEGMA with benzyl methacrylate (BzMA) in ethanol (EtOH), polymeric nanoparticles with different morphologies are formed in situ according to a polymerization-induced self-assembly (PISA) mechanism. Self-assembly into nanoparticles presenting POEGMA chains at the corona and poly(benzyl methacrylate) (PBzMA) chains in the core occurs in situ due to the growing insolubility of the PBzMA block in ethanol. Interestingly, the formation of highly pure worm-like micelles can be readily monitored by observing the onset of a highly viscous gel in situ due to nanoparticle entanglements occurring during the polymerization. This process thereby allows for a more reproducible synthesis of worm-like micelles simply by monitoring the solution viscosity during the course of the polymerization. In addition, the light stimulus can be intermittently applied in an ON/OFF manner demonstrating temporal control over the nanoparticle morphology.

This article describes a process for producing polymeric self-assembled nanoparticles using visible light mediated dispersion polymerization. Using low energy visible light to control the polymerization allows for the reproducible formation of self-assembled worm-like micelles at high solids content.

使用Photoredox催化剂蠕虫状胶束的简便合成可见光介导的分散聚合

Presented herein is a protocol for the facile synthesis of worm-like micelles by visible light mediated dispersion polymerization. This approach begins ...

Controlled Synthesis and Fluorescence Tracking of Highly Uniform Poly(N-isopropylacrylamide) Microgels

Stimuli-sensitive poly(N-isopropylacrylamide) (PNIPAM) microgels have various prospective practical applications and uses in fundamental research. In this work, we use single particle tracking of fluorescently labeled PNIPAM microgels as a showcase for tuning microgel size by a rapid non-stirred precipitation polymerization procedure. This approach is well suited for prototyping new reaction compositions and conditions or for applications that do not require large amounts of product. Microgel synthesis, particle size and structure determination by dynamic and static light scattering are detailed in the protocol. It is shown that the addition of functional comonomers can have a large influence on the particle nucleation and structure. Single particle tracking by wide-field fluorescence microscopy allows for an investigation of the diffusion of labeled tracer microgels in a concentrated matrix of non-labeled microgels, a system not easily investigated by other methods such as dynamic light scattering.

Controlled Synthesis and Fluorescence Tracking of Highly Uniform PolyN-isopropylacrylamide Microgels

Non-stirred precipitation polymerization provides a rapid, reproducible prototyping approach to the synthesis of stimuli-sensitive poly(N-isopropylacrylamide) microgels of narrow size distribution. In this protocol synthesis, light scattering characterization and single particle fluorescence tracking of these microgels in a wide-field microscopy setup are demonstrated.

可控合成和高度统一聚荧光追踪（<em&gt;ñ</em&gt; -isopropylacrylamide）微凝胶

Stimuli-sensitive poly(N-isopropylacrylamide) (PNIPAM) microgels have various prospective practical applications and uses in fundamental research. In this ...

From Molecules to Materials: Engineering New Ionic Liquid Crystals Through Halogen Bonding

Herein, we demonstrate that a bottom-up approach, based on halogen bonding (XB), can be successfully applied for the design of a new type of ionic liquid crystals (ILCs). Taking advantages of the high specificity of XB for haloperfluorocarbons and the ability of anions to act as XB-acceptors, we obtained supramolecular complexes based on 1-alkyl-3-methylimidazolium iodides and iodoperfluorocarbons, overcoming the well-known immiscibility between hydrocarbons (HCs) and perfluorocarbons (PFCs). The high directionality of the XB combined with the fluorophobic effect, allowed us to obtain enantiotropic liquid crystals where a rigid, non-aromatic, XB supramolecular anion acts as mesogenic core.
X-ray structure analysis of the complex between 1-ethyl-3-methylimidazolium iodide and iodoperfluorooctane showed the presence of a layered structure, which is a manifestation of the well-known tendency to segregation of perfluoroalkyl chains. This is consistent with the observation of smectic mesophases. Moreover, all the reported complexes melt below 100 &#176;C, and most are mesomorphic even at room temperature, despite that the starting materials were non-mesomorphic in nature.
The supramolecular strategy reported here provides new design principles for mesogen design allowing a totally new class of functional materials.

A protocol for the synthesis of a new type of mesogens, based on the halogen-bonded supramolecular anion [CnF2n+1-I&#183;&#183;&#183;I&#183;&#183;&#183;I-CnF2n+1]&#8722;, is reported.

从分子到材料: 通过卤素键合工程新的离子液体晶体

Herein, we demonstrate that a bottom-up approach, based on halogen bonding (XB), can be successfully applied for the design of a new type of ionic liquid ...

Rapid Nanoprobe Signal Enhancement by In Situ Gold Nanoparticle Synthesis

The use of nanoprobes such as gold, silver, silica or iron-oxide nanoparticles as detection reagents in bioanalytical assays can enable high sensitivity and convenient colorimetric readout. However, high densities of nanoparticles are typically needed for detection. The available synthesis-based enhancement protocols are either limited to gold and silver nanoparticles or rely on precise enzymatic control and optimization. Here, we present a protocol to enhance the colorimetric readout of gold, silver, silica, and iron oxide nanoprobes. It was observed that the colorimetric signal can be improved by up to a 10000-fold factor. The basis for such signal enhancement strategies is the chemical reduction of Au3+ to Au0. There are several chemical reactions that enable the reduction of Au3+ to Au0. In the protocol, Good&#39;s buffers and H2O2 are used and it is possible to favor the deposition of Au0 onto the surface of existing nanoprobes, in detriment of the formation of new gold nanoparticles. The protocol consists of the incubation of the microarray with a solution consisting of chloroauric acid and H2O2 in 2-(N-morpholino)ethanesulfonic acid pH 6 buffer following the nanoprobe-based detection assay. The enhancement solution can be applied to paper and glass-based sensors. Moreover, it can be used in commercially available immunoassays as demonstrated by the application of the method to a commercial allergen microarray. The signal development requires less than 5 min of incubation with the enhancement solution and the readout can be assessed by naked eye or low-end image acquisition devices such as a table-top scanner or a digital camera.

Rapid Nanoprobe Signal Enhancement by In Situ Gold Nanoparticle Synthesis

In this work, a protocol for signal enhancement of nanoprobe-based biosensing is presented. The protocol is based on the reduction of chloroauric acid onto the surface of existing nanoprobes that consist of gold, silver, silica or iron-oxide nanoparticles.

原位金纳米粒子合成快速 Nanoprobe 信号增强

The use of nanoprobes such as gold, silver, silica or iron-oxide nanoparticles as detection reagents in bioanalytical assays can enable high sensitivity ...

Chemical Synthesis of Porous Barium Titanate Thin Film and Thermal Stabilization of Ferroelectric Phase by Porosity-Induced Strain

Barium titanate (BaTiO3, hereafter BT) is an established ferroelectric material first discovered in the 1940s and still widely used because of its well-balanced ferroelectricity, piezoelectricity, and dielectric constant. In addition, BT does not contain any toxic elements. Therefore, it is considered to be an eco-friendly material, which has attracted considerable interest as a replacement for lead zirconate titanate (PZT). However, bulk BT loses its ferroelectricity at approximately 130 &#176;C, thus, it cannot be used at high temperatures. Because of the growing demand for high-temperature ferroelectric materials, it is important to enhance the thermal stability of ferroelectricity in BT. In previous studies, strain originating from the lattice mismatch at hetero-interfaces has been used. However, the sample preparation in this approach requires complicated and expensive physical processes, which are undesirable for practical applications.
In this study, we propose a chemical synthesis of a porous material as an alternative means of introducing strain. We synthesized a porous BT thin film using a surfactant-assisted sol-gel method, in which self-assembled amphipathic surfactant micelles were used as an organic template. Through a series of studies, we clarified that the introduction of pores had a similar effect on distorting the BT crystal lattice, to that of a hetero-interface, leading to the enhancement and stabilization of ferroelectricity. Owing to its simplicity and cost effectiveness, this fabrication process has considerable advantages over conventional methods.

Here, we present a protocol for the synthesis of porous barium titanate (BaTiO3) thin film by a surfactant-assisted sol-gel method, in which self-assembled amphipathic surfactant micelles are used as an organic template.