Transmembrane anion transport mediated by adamantyl-functionalised imidazolium salts

We present the design, synthesis and transmembrane anion transport properties of a new class of mobile organic transporters, possessing a central imidazolium cation and two external adamantyl units. We demonstrate herein that the imidazolium cation can be incorporated in the structure of active mobile anion transporters. Depending on the nature of the counter-anion of the salt, as well as the extravesicular anions, different anion selectivities were obtained. We show the importance of the H2 proton of the imidazolium cation in order to obtain a higher binding constant of the chloride anion. Furthermore, we demonstrate the importance of the flexibility of the spacers between the adamantyl groups and the imidazolium cation in the transport process.     

Perrhenate and pertechnetate anion recognition properties of cyclo[8]pyrrole

Cyclo[8]pyrrole, an octapyrrolic expanded porphyrin with no meso-linking atoms, was found to interact with a series of anions in the solid state and in a chloroform solution. The anion selectivities have been determined relative to a structurally characterised salt, H₂cyclo[8]pyrrole²⁺·I^? ·I^3 ? , via counter anion exchange. Although cyclo[8]pyrrole demonstrates a general selectivity for sulfate, it interacts well with both the pertechnetate and perrhenate anions. Moreover, it has been shown to act as a phase-transfer catalyst facilitating the extraction of pertechnetate from an aqueous to an organic phase in the presence of sulfate.     

A novel double polymer modified hydrophobic/hydrophilic stationary phase for liquid chromatography

In this paper,norbornene imidazolium hexafluorophosphate(NM-MIm-PF6)was modified on the surface of aminopropyl silica by ring-opening metathesis polymerization(ROMP),and then oligo(ethylene glycol)methacrylate(OEGMA)were grafted on the surface by atom transfer radical polymerization(ATRP).Some characterizations in this article confirmed that the synthesis of P(NM-MIm-PF6)-SiPOEGMA(Pl-Si-P2)is successful.The P1-Si-P2 can separate sugars,amino acids,sulfonamides in a hydrophilic interaction mode and alkyl benzene,polycyclic aromatic hydrocarbon in a reverse phase mode.The experiment also found that the column has typical characte ristics of hydrophobic/hydrophilic separation mechanism.Compared to single hydrophobic C18 column and single hydrophilic Si-NH2 column,this P1-Si-P2 shows certain advantages.     

芳氧功能化咪唑基五氯化铕[HO-4,6-di-tBu-C6H2-2-CH2{CH（NCHCHNiPr）}]2+[EuCl5（THF）]2-的合成与结构

芳氧功能化咪唑盐L+Cl-(L=HO-4,6-di-tBu-C6H2-2-CH2{CH[iPrNCHCHN]})与无水EuCl3分别按照摩尔比为1∶2和1∶3反应成功合成相同芳氧功能化咪唑基五氯化铕L+2[EuCl5(THF)]2-,产物通过元素分析、IR、X-ray射线衍射表征。晶体结构数据表明此配合物属于单斜晶体,空间群P21/c,晶胞参数a=0.96664(8)nm,b=1.63312(12)nm,c=3.6850(3)nm,β=97.600(2)°,V=5.7662(8)nm3,Mr=1060.30,Z=4,Dc=1.221 Mg/m3,μ(MoKα)=1.36 mm-1,F(000)=2200。目标化合物是由阴离子[EuCl5(THF)]2-和[HO-4,6-di-tBu-C6H2-2-CH2{CH(iPrNCHCHN)}]2+通过氢键作用而形成的空间网状结构的晶体,阴离子中中心金属(Eu)是由五个氯原子以及来自THF的氧原子形成扭曲八面体的构型。     

咪唑类离子液体的合成及其在分析化学中的应用

本文介绍了咪唑类离子液体的合成,特别是以BF4-、PF6-为阴离子的咪唑类离子液体的合成,并重点综述了近年来咪唑类离子液体在电化学分析、质谱、光谱、色谱及毛细管电泳等分析化学中的应用.     

微波法合成离子液体1-乙基-3-甲基咪唑四氟硼酸盐的研究

离子液体(ionic liquids)是在室温下液态的一种熔融盐,又称为室温离子液体,一般由有机阳离子和无机阴离子或者有机阴离子构成,可以通过调节阴阳离子的种类来改变离子液体的性能,因此敢称为一种"可以设计的溶剂".     

整体柱和填充柱离子对色谱-间接紫外检测法分析四乙基铵根离子

建立了整体柱离子对色谱-间接紫外检测和填充柱离子对色谱-间接紫外检测分析四乙基铵根离子的两种方法。用反相整体柱和反相填充柱,以咪唑离子液体-离子对试剂-有机溶剂为流动相,研究了背景紫外吸收试剂、检测波长、离子对试剂、有机溶剂、柱温和流速对测定四乙基铵根离子的影响,比较了两种色谱柱的差异,并讨论了保留规律。在优化的实验条件下,两种方法测定四乙基铵根离子的保留时间分别是2.40和3.02 min;检出限分别是0.04和0.07 mg/L;峰面积的相对标准偏差分别是0.16%和0.11%;保留时间的相对标准偏差分别是0.02%和0.01%。将这两种方法用于分析实验室合成的溴化四乙基铵离子液体,加标回收率分别为98.2%和99.1%。两种方法均能满足四乙基铵根离子测定的需要。     

Ionic liquid structure: the conformational isomerism in 1‐butyl‐3‐methyl‐imidazolium tetrafluoroborate ([bmim][BF4])

As a probe of local structure, the vibrational properties of the 1‐butyl‐3‐methylimidazolium tetrafluoroborate [bmim][BF₄] ionic liquid were studied by infrared (IR), Raman spectroscopy, and ab initio calculations. The coexistence of at least four [bmim]⁺ conformers (GG, GA, TA, and AA) at room temperature was established through unique spectral responses. The Raman modes characteristic of the two most stable [bmim]⁺ conformers, GA and AA, according to the ab initio calculations, increase in intensity with decreasing temperature. To assess the total spectral behavior of the ionic liquid both the contributions of different [bmim]⁺ conformers and the [bmim]⁺− [BF₄]⁻ interactions to the vibrational spectra are discussed. Copyright © 2008 John Wiley & Sons, Ltd.     

Peptide Stapling by Crosslinking Two Amines with α-Ketoaldehydes through Diverse Modified Glyoxal-Lysine Dimer Linkers

α-Ketoaldehydes play versatile roles in the ubiquitous natural processes of protein glycation. However, leveraging the reactivity of α-ketoaldehydes for biomedical applications has been challenging. Previously, the reactivity of α-ketoaldehydes with guanidine has been harnessed to design probes for labeling Arg residues on proteins in an aqueous medium. Herein, a highly effective, broadly applicable, and operationally simple protocol for stapling native peptides by crosslinking two amino groups through diverse imidazolium linkers with various α-ketoaldehyde reagents is described. The use of hexafluoroisopropanol as a solvent facilitates rapid and clean reactions under mild conditions and enables unique selectivity for Lys over Arg. The naturally occurring GOLD/MOLD linkers have been expanded to encompass a wide range of modified glyo xal-l ysine d imer (OLD) linkers. In a proof-of-concept trial, these modular stapling reactions enabled a convenient two-round strategy to streamline the structure–activity relationship (SAR) study of the wasp venom peptide anoplin, leading to enhanced biological activities.     

胡椒基咪唑盐类化合物的合成及生物活性研究

从胡椒酸出发,通过还原、甲磺酸酯化、偶联和成盐四步反应合成了一系列新型的胡椒基咪唑盐类化合物,其结构经¹HNMR, ¹³CNMR,HRMS以及X射线单晶衍射确定.对合成的新化合物进行了体外抗肿瘤细胞毒活性筛选,结果表明,1-((苯并[d][1,3]二氧杂环戊烯-5-基甲基)-3-(2-萘甲基))-5,6-二甲基-1H-苯并[d]咪唑-3-溴盐(30)具有显著的细胞毒活性,对HL-60、SMMC-7721、A-549、MCF-7和SW-480肿瘤细胞株的活性均优于顺铂(DDP),尤其对HL-60肿瘤细胞株表现出较好的选择性细胞毒活性,其IC₅₀值约为顺铂的7.2倍.进一步研究表明,化合物30具有诱导SMMC-7721细胞株在细胞周期G0/G1期阻滞和细胞凋亡的作用.