Room-Temperature Ionic Liquids: For a Difference in the Supramolecular Synthesis

Cu(I) and Ni(II) coordination polymers with 4,4′-bipyridine and 2,2′-bipyridine, respectively, that have been synthesized from an ionic liquid (1-ethyl-3-methylimidazolium tetrafluoroborate) gave different coordination environment and supramolecular networks than the corresponding synthesis from the other solvents. The resultant complexes were characterized by single crystal x-ray diffraction methods.     

Switching the Solubility of PMMA Bearing Attached Cyclodextrin‐Moieties by Supramolecular Interactions with Ionic Liquids

Methacrylate‐modified β‐cyclodextrin (β‐CD) and methyl methacrylate (MMA) have been radically copolymerized to obtain hydrophobic CD copolymers. The water‐insoluble copolymers are able to form highly stable inclusion complexes with anions of ionic liquids. Surprisingly, the inclusion of the anions in the CD cavity results in a significant change of thermal and solution properties. Furthermore, it can be shown that the structure of the ionic liquid anions influences the coil structure of the copolymers. The obtained results could be proven by means of microcalorimetry, differential scanning calorimetry, and dynamic light scattering.

     

离子液体应用于电合成导电聚合物*

自20世纪70年代导电聚合物发现以来,聚吡咯、聚苯胺、聚噻吩、聚（3,4-乙撑二氧噻吩）、聚对苯及其衍生物等,以其特殊的电子、电化学、光学性质以及巨大应用潜力受到广泛关注。离子液体是一类在室温或接近室温时呈液态的离子化合物,作为一类环境友好的新型绿色溶剂,具有很多独特的物理化学性质。本文综述了离子液体作为反应介质、支持电解质、测试介质以及离子液体参与形成的聚集体,在导电聚合物的电化学合成以及电化学性质测试中的研究进展,并展望了发展趋势。     

Chiral Triazolium Salts and Ionic Liquids: From the Molecular Design Vectors to Their Physical Properties through Specific Supramolecular Interactions

An exhaustive experimental study based on X‐ray diffraction analysis, NMR, FTIR‐ATR (attenuated total reflection), and Raman spectroscopy as well as theoretical calculations is reported in order to understand how the non‐covalent intermolecular contacts are fundamental to explain structure–property relationships and allowing us to correlate a basic macroscopic property (i.e., the melting point, T_m) with the structural variables of a family of enantiopure 1,4‐dialkyl‐1,2,4‐triazolium salts. The effect of different structural vectors such as the ring size, the spatial disposition of the substituent, the substitution on the oxygen atom, the nature of the anion, or the N4 alkylation of the triazole on the intermolecular interactions of these chiral salts of a well‐defined 3D structure is reported. The non‐covalent intermolecular contacts mainly implicating the triazolium H3 proton are fundamental to explain structure–property relationships and, therefore, the physical properties of these new chiral salts, rather than simple anion–cation interactions. Overall, our findings highlight the importance of the specific supramolecular interactions for the understanding of the physical properties of triazolium salts and ionic liquids.     

Visible-to-UV Photon Upconversion in Nanostructured Chromophoric Ionic Liquids

Visible-to-ultraviolet (vis-to-UV) triplet-triplet annihilation based photon upconversion (TTA-UC) is achieved in a non-volatile chromophoric ionic liquid (IL) for the first time. A novel IL is synthesized by combining UV-emitting anion 4-(2-phenyloxazol-5-yl)benzenesulfonate (PPOS) and trihexyltetradecylphosphonium cation (P₆₆₆₁₄). The nanostructured organization of chromophoric anions is demonstrated by synchrotron X-ray and optical measurements. When the IL is doped with a triplet sensitizer tris(2-phenylpyridinato)iridium(III) (Ir(ppy)₃), the visible-to-UV TTA-UC with a relatively low threshold excitation intensity of 61 mW cm⁻² is achieved. This is due to a large triplet diffusion coefficient in the IL (1.4×10⁻⁷ cm² s⁻¹) as well as a high absorption coefficient 15 cm⁻¹ and a long PPOS triplet lifetime of 1.55 ms, all implemented in the condensed IL system. This work demonstrates the unique potential of ILs to control chromophore arrangements for desired functions.     

New Organic Dispersions of Conducting Polymers Using Polymeric Ionic Liquids as Stabilizers

Summary: Polypyrrole (PPy), polyaniline (PANI), and poly(ethylenedioxythiophene) (PEDOT) aqueous dispersions were prepared by polymerizing the corresponding monomer in the presence of a polymeric ionic liquid (PIL), poly(1‐vinyl‐3‐ethylimidazolium bromide). By addition of bispentafluoroethanesulfonimide lithium salt, the PIL stabilizer becomes hydrophobic and precipitates in water and traps the conducting polymer microparticles inside. The dispersion of the recovered powders in organic solvents leads to organic conducting dispersions. After casting the organic dispersions, hydrophobic films with electrical conductivity values as high as 0.1 S · cm⁻¹ were obtained.

A new synthetic route to new organic dispersions.     

Facile Synthesis of Supramolecular Ionic Polymers That Combine Unique Rheological,Ionic Conductivity,and Self‐Healing Properties

A new family of supramolecular ionic polymers is synthesized by a simple method using (di‐/tri‐)carboxylic acids and (di‐/tri‐)alkyl amines. These polymers are formed by carboxylate and ammonium molecules that are weakly bonded together by a combination of ionic and hydrogen bonds, becoming solid at room temperature. The supramolecular ionic polymers show a sharp rheological transition from a viscoelastic gel to a viscous liquid between 30 and 80 °C. This sharp viscosity decrease is responsible for an unprecedented jump in ionic conductivity of four orders of magnitude in that temperature range. As a potential application, this chemistry can be used to develop polymeric materials with self‐healing properties, since it combines properties from supramolecular polymers and ionomers into the same material.     

Cucurbituril‐Modulated Supramolecular Assemblies: From Cyclic Oligomers to Linear Polymers

Employing bis(p‐sulfonatocalix[4]arenes) (bisSC4A) and N′,N′′hexamethylenebis(1‐methyl‐4,4′‐bipyridinium) (HBV⁴⁺) as monomer building blocks, the assembly morphologies can be modulated by cucurbit[n]uril (CB[n]) (n=7, 8), achieving the interesting topological conversion from cyclic oligomers to linear polymers. The binary supramolecular assembly fabricated by HBV⁴⁺ and bisSC4A units, forms an oligomeric structure, which was characterized by NMR spectroscopy, atomic force microscopy (AFM), transmission electron microscopy (TEM), dynamic light scattering (DLS), isothermal titration calorimetry (ITC), and gel permeation chromatography (GPC) experiments. The ternary supramolecular polymer participated by CB[8] is constructed on the basis of host–guest interactions by bisSC4A and the [2]pseudorotaxane HBV⁴⁺@CB[8], which is characterized by means of AFM, DLS, NMR spectroscopy, thermogravimetric analysis (TGA), UV/Vis spectroscopy, and elemental analysis. CB[n] plays vital roles in rigidifying the conformation of HBV⁴⁺, and reinforcing the host–guest inclusion of bisSC4A with HBV⁴⁺, which prompts the formation of a linear polymer. Moreover, the CB[8]‐participated ternary assembly could disassemble into the molecular loop HBV²⁺@CB[8] and free bisSC4A after reduction of HBV⁴⁺ to HBV²⁺, whereas the CB[7]‐based assembly remained unchanged after the reduction. CB[8] not only controlled the topological conversion of the supramolecular assemblies, but also improved the redox‐responsive assembly/disassembly property practically.     

Tuning the Properties of Functional Pyrrolidinium Polymers by (Co)polymerization of Diallyldimethylammonium Ionic Liquids

The synthesis and polymerization of novel diallyldimethylammonium ionic liquid monomers is described. A free‐radical polymerization follows a ring‐closing cyclopolymerization mechanism similar to the one observed previously for diallyldimethylammonium halides that leads to pyrrolidinium functional polymers. As previously observed in other families of polymeric ionic liquids, their physico‐chemical properties are seriously affected by the nature of the counter‐anion. As an example, the thermal stability increases following the trend SCN⁻ < < < bis(trifluoromethane)sulfonamide. Interestingly, this polymerization route may lead to the synthesis of a new family of random copolymers that have a similar poly(diallyldimethylammonium) backbone and a mixture of counter‐anions determined by the comonomer selection.

     

Supramolecular Ionic‐Liquid Gels with High Ionic Conductivity

Supramolecular ionogels were prepared by the gelation of room‐temperature ionic liquid 1‐butyl‐3‐methylimidazolium tetrafluoroborate ([BMIm][BF₄]) with (S,S)‐bis(leucinol)oxalamide. Remarkably, the ionic conductivity of solutions and ionogels with low gelator concentrations is higher than that of neat [BMIm][BF₄]. On the basis of molecular dynamics simulations and quantum mechanical calculations, the origin of this phenomenon is attributed to the higher affinity of gelator molecules towards [BF₄]^? ions, which reduces the electrostatic attraction between [BMIm]⁺ and [BF₄]^? and thus increases their mobility. With increasing gelator concentration, the ionic conductivity decreases due to the formation of a denser gelator matrix, which hinders the pathways for ionic transport. However, even for very dense ionogels, this decrease is less than one order of magnitude relative to neat [BMIm][BF₄], and thus they can be classified as highly conductive materials with strong potential for application as functional electrolytes.     

基于氢键作用结合的超分子聚合物

非共价键结合的超分子聚合物由于其特殊的结构及性能引起了广泛的关注。本文在介绍超分子化学、氢键及超分子聚合物的基础上,主要综述了以氢键为结合力的多重氢键作用、羧基（D）与吡啶基（A）作用以及氢键与其它非共价键协同作用形成的超分子聚合物体系,并对超分子聚合物的研究现状及前景进行了评述。     

Binding Selectivity of Macrocycle Ionophores in Ionic Liquids versus Aqueous Solution and Solvent‐free Conditions

The understanding of supramolecular recognition in room‐temperature ionic liquids (RTILs) is key to develop the full potential of these materials. In this work, we provide insights into the selectivity of the binding of alkali metal cations by standard cyclodextrin and calixarene macrocycles in RTILs. A direct laser desorption/ionization mass spectrometry approach is employed to determine the relative abundances of the inclusion complexes formed through competitive binding in RTIL solutions. The results are compared with the binding selectivities measured under solvent‐free conditions and in water/methanol solutions. Cyclodextrins and calixarenes in which the peripheral OH groups are substituted by bulkier side groups preferentially bind to Cs⁺. Such specific ionophoric behavior is substantially enhanced by solvation effects in the RTIL. This finding is rationalized with the aid of quantum mechanical calculations, in terms of the conformational features and steric interactions that drive the solvation of the inclusion complexes by the bulky RTIL counterions.     

基于氢键作用结合的超分子聚合物

非共价键结合的超分子聚合物由于其特殊的结构及性能引起了广泛的关注。本文在介绍超分子化学、氢键及超分子聚合物的基础上,主要综述了以氢键为结合力的多重氢键作用、羧基(D)与吡啶基(A)作用以及氢键与其它非共价键协同作用形成的超分子聚合物体系,并对超分子聚合物的研究现状及前景进行了评述。     

基于离子液体辅助氯霉素分子印迹聚合物的制备及应用

以氯霉素(CAP)为模板,2-乙烯基吡啶(2-Vp)为功能单体,四氢呋喃和离子液体1-丁基-3-甲基咪唑四氟硼酸盐[BMIm]BF4的混合溶液为反应溶剂,乙二醇二甲基丙烯酸酯(EGDMA)为交联剂,偶氮二异丁腈(AIBN)为引发剂,合成了氯霉素的分子印迹及非印迹聚合物。优化功能单体、不同溶剂对印迹聚合物吸附性能的影响,结果表明,以2-乙烯基吡啶为功能单体,四氢呋喃和离子液体[BMIm]BF4(体积比1∶1)作为反应溶剂合成的分子印迹聚合物对氯霉素具有高的吸附容量,良好的特异性识别性能。氯霉素分子印迹聚合物的印迹因子为2.6,进行吸附-解吸附循环5次后,氯霉素印迹聚合物的性能稳定,可重复使用。将制备的氯霉素分子印迹聚合物作为富集材料,应用于鸡蛋样品中氯霉素的检测,回收率可达62.3%~81.1%,准确性好。     

Advanced Materials Based on Polymers and Ionic Liquids

Ionic liquids (ILs) are ambient temperature molten salts, which have attracted considerable attention owing to their unique properties. In this contribution, we review advanced materials composed of ILs and polymers for the basis of a new design protocol to fabricate novel materials. As electrolytes for electrochemical devices, cross‐linked polymers containing ILs (ion gels) are endowed with functional properties inherited from ILs and mechanical consistency derived from polymers. To create such materials, micro‐phase separation of block copolymers and colloidal arrays in the ILs are utilized. Based on the molecular design of task‐specific ILs, the resultant ion gels are applicable as electrolytes for actuator, fuel cell, and secondary battery applications. Thermo‐ and photo‐responsive polymers in ILs are also highlighted, whereby such stimuli elicit changes in the solubility of the self‐assembly of block copolymers and colloidal arrays in the ILs. Further, thermo‐ and photo‐reversible changes in the self‐assembled structure can be exploited to demonstrate sol‐gel transitions and fabricate photo‐healable materials.     

聚合物在咪唑类离子液体中的溶解

离子液体（ILs）具有难挥发、热稳定、宽液程和高电导率等独特优点,在聚合物领域中的应用受到越来越多的关注。由于ILs内部的复杂相互作用力,ILs的溶剂化能力还不能像分子溶剂那样有定量的方法来表征,特别是ILs与聚合物的相容性没有一个统一的判据。本文从咪唑基ILs内部的四个主要相互作用力出发,简述了ILs内部的相互作用对...     

Deep Eutectic Supramolecular Polymers: Bulk Supramolecular Materials

Application of new strategies for supramolecular self‐assembly can significantly impact the properties and/or functions of supramolecular polymers. To realize a facial strategy for the development of solvent‐free supramolecular polymers in bulk, “deep eutectic solvents” were employed. Cyclodextrins and natural acids were used to prepare deep eutectic supramolecular polymers ( DESP s). Deep eutectic solvents have special characteristics that endow DESP s with unique macroscopic properties and excellent processability. DESP s exhibit supramolecular adhesion and temperature‐dependent behavior originating from the combined effects of deep eutectic solvents and supramolecular polymerization. Because DESP s are solvent‐free and display interesting macroscopic properties, they have potential as new adaptive materials.     

多肽基超分子螺旋聚合物

超分子螺旋聚合物结合了超分子聚合物制备方法简便、结构及性能可调控等优势,相比于人工合成的共价型螺旋聚合物更接近自然界螺旋生物大分子,因而在手性探针、不对称催化以及手性识别和分离等领域具有广泛的应用前景。结合多肽的手性优势、丰富的二次有序构象及其出色的自组装行为,以多肽作为结构基元经超分子组装制备具有螺旋构象的聚合物,不仅丰富了手性/螺旋聚合物的制备途径,同时为多肽材料的功能化应用提供新的广阔前景。本文综述了多肽基元之间经超分子作用诱导形成的超分子螺旋聚合物,总结了双亲性多肽以及多肽拓扑结构对超分子组装过程的影响及其对形成螺旋结构的控制,重点归纳了由多肽构筑的光、温度、pH、金属离子和酶等不同类型智能响应性的超分子螺旋聚合物。     

咪唑基离子液体非共价修饰的石墨烯结构与分散性

在离子液体氯化-1-烯丙基-3-甲基咪唑（AmimCl）存在的条件下,利用水合肼对氧化石墨烯进行同步还原,制备了一种可稳定分散在N,N-二甲基甲酰胺（DMF）和乙酸丁酯等有机溶剂中的离子液体改性石墨烯（IL-G）。运用红外光谱（FTIR）、紫外-可见吸收光谱（UV-Vis）、热失重分析（TGA）、原子力显微镜（AFM）、拉曼光谱（Raman）、X射线电子衍射（XRD）和X射线光电子能谱（XPS）对制备的改性石墨烯进行结构性能测试,结果表明离子液体AmimCl与石墨烯之间存在π-π和阳离子-π的相互作用,能较好的吸附在石墨烯表面。TGA测试表明IL-G中离子液体的比例约为7.20wt%。同时,AFM结果显示改性石墨烯剥离在DMF中的平均厚度是0.962nm。由于非共价改性石墨烯可再分散于DMF和乙酸丁酯中,通过紫外可见吸收光谱测得其最大分散浓度分别是1.69mg·mL^-1和1.12mg·mL^-1。