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Imidazolium salts are privileged compounds in organic chemistry, and have valuable biological properties. Recent studies show that symmetric imidazolium salts with bulky moieties can display antiparasitic activity against T. cruzi. After developing a facile methodology for the synthesis of tetrasubstituted imidazolium salts from propargylamines and isocyanides, we screened a small library of these adducts against the causative agents of African and American trypanosomiases. These compounds display nanomolar activity against T. brucei and low (or sub) micromolar activity against T. cruzi, with excellent selectivity indexes and favorable molecular properties, thereby emerging as promising hits for the treatment of Chagas disease and sleeping sickness.

Three series of podophyllotoxin derivatives with various nitrogen-containing heterocycles were designed and synthesized. The antitumor activity of these podophyllotoxin derivatives was evaluated in vitro against a panel of human tumor cell lines. The results showed that podophyllotoxin-imidazolium salts and podophyllotoxin-1,2,4-triazolium salts a1-a20 exhibited excellent cytotoxic activity. Among them, a6 was the most potent cytotoxic compound with IC 50 values of 0.04-0.29 μM. Podophyllotoxin-1,2,3-triazole derivatives b1-b5 displayed medium cytotoxic activity, and podophyllotoxin-amine compounds c1-c3 has good cytotoxic activity with IC 50 value of 0.04-0.58 μM. Furthermore, cell cycle and apoptosis experiments of compound a6 were carried out and the results exhibited that a6 could induce G2/M cell cycle arrest and apoptosis in HCT-116 cells., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Yin, Fang, Sun, Xue, Zhang, Zhu, Meng, Kong, Myint, Li, Zhao and Yang.)

Treatment of N-heterocyclic carbene (1,3-Bis(2,6-diisopropylphenyl)-1,3-dihydro-2H-imidazol-2-ylidene; (L Dipp )) with different sources of hydrofluoric acid (Et 3 N∙3HF, anhydrous hydrofluoric acid and KHF 2 ) in 1:1, 1:2, 1:3 ratios affords [(L Dipp )H] + [F] − ( 1 ), [(L Dipp )H] + [(HF)F] − ( 2 ) and [(L Dipp )H] + [(HF) 2 F] − ( 3 ) salts respectively. Different fluoride sources all yield the same products, but ease of manipulation and isolation can influence the choice in the future use. Compound ( 1 ), which shows characteristics of a free fluoride reagent, can be obtained with good yield and without the contaminants usually present in such compounds. All products were characterized by X-Ray crystallography, NMR spectroscopy and free fluoride (F f − ) chemical analysis. [ABSTRACT FROM AUTHOR]

Aims This study demonstrates the development of a mouthwash formulation containing the imidazolium salt ( IMS) 1- n-hexadecyl-3-methylimidazolium chloride (C16 MImCl), considering its stability and efficacy against Candida sp. Biofilm formation. Methods and Results A variety of in vitro test methods were applied, assessing contaminated acrylic resin strip specimens before and after applying the mouthwash formulations. The formulation using C16 MImCl presented a similar antibiofilm activity to cetylpyridinium chloride one and a commercial mouthwash, but at a 10 times lower concentration. Scanning electron microscopy imaging demonstrated that the selected mouthwash preparation fully destroys the biofilm cells, while with the hypoallergenicity test no irritant effect was observed in ex vivo model. Conclusions The results presented herein indicate a high potential for imidazolium salts application as mouthwash agents that can eliminate Candida biofilm growth at very low concentrations. Significance and Impact of the Study This study demonstrates a new and effective antibiofilm formulation containing the IMS C16 MImCl. These findings suggest the IMS' use as mouthwash formulations active ingredient against Candida biofilms on oral surfaces, as it outperforms the often used cetylpyridinium chloride at a 10 times lower concentration. [ABSTRACT FROM AUTHOR]

Readily available iron(III)-based imidazolium salts have proven to be very versatile catalysts for the allylic substitution reaction of alcohols with anilines, allowing the synthesis of quinolines, 2-allylanilines and 4-allylanilines just by modulating the reaction conditions. Noteworthy, the formation of quinoline derivatives proceeds by ortho-allylation of the corresponding aniline and subsequent oxidative cyclization mediated by atmospheric oxygen. The reaction using anilines as nucleophiles is selective to the C-alkylation versus the N-alkylation, under any reaction conditions studied. [ABSTRACT FROM AUTHOR]

A new imino-functionalized imidazolium salt, 1-[1-(2,6-diisopropylphenylimino)ethyl]-3-benzylimidazolium chloride ([HL]Cl,), was designed and used to prepare a novel ionic iron(III) complex [HL][FeCl 4 ] ( 2 ). Complex 2 was an efficient and easy-to-use catalyst for the direct sp 3 C–H bond amidation of N , N -dimethylanilines, affording a wide variety of N -substituted aromatic or aliphatic amides in moderate to good yields. This reaction is the first example of iron-catalyzed intermolecular amidation of unactivated sp 3 C–H bonds of tertiary amines by aromatic or aliphatic amides under mild reaction conditions. [ABSTRACT FROM AUTHOR]

The reaction of 1-methylimidazole, 2-ethyl-4-methylimidazole and 2-ethylimidazole with tris(2,6-diisopropylphenoxy)silanethiol (TDST) leads to the formation of three new salts, which have been characterized by elemental analyses, thermogravimetric analyses, FTIR spectroscopy, and their structures were determined by single-crystal X-ray diffraction. Structural analyses indicate that in all three compounds a proton transfer has occurred from the SH group of TDST onto the imidazole nitrogen atom, giving charge-assisted (+) N–H⋯S (−) hydrogen bonds. The crystallographic characterization of the compounds reveals structural diversity. Compound 1 exhibit zero-dimensional (0-D) hydrogen bonded entities, while compounds 2 and 3 form one-dimensional (1-D) supramolecular networks. The transfer of the proton was confirmed by FTIR spectroscopy in the solid state. Computational studies on the compounds were carried out with the use of the density functional theory (DFT) method with the B3LYP functional at the TZV level. [ABSTRACT FROM AUTHOR]

The synthesis, characterization and in situ catalytic performance of new unsymmetric N, N′-disubstituted imidazolium-based dicationic salts in Mizoroki-Heck coupling of acrylates with aryl bromides under aerobic conditions are described. A series of flexible dicationic salts with varying steric and electronic properties were synthesized in good to excellent yields. All the salts were well characterized using spectroscopic techniques. X-ray diffraction analysis of two salts with the same dicationic backbone and different counter anions shows that the ligand adopts two different conformations which are influenced by the nature of the anion. Thus, the ligand is capable of changing its conformation according to the change in environment due to its flexible nature. All the synthesized imidazolium salts were found to be active in in situ palladium-catalysed Mizoroki-Heck coupling under aerobic conditions. Amongst the salts, the hydroxyl-functionalized imidazolium salt, incorporating the features of both bidentate chelating O, O ligand and carbene, shows the maximum . A variety of aryl and heteroaryl methyl and ethyl cinnamates were synthesized using these imidazolium salts as preligands. In addition, NMR studies confirm in situ generation of normal N-heterocyclic carbenes from the C-2 position of imidazol-2-ylidene ring. The mercury poisoning test was also performed to ascertain the nature of catalytically active palladium species. Aerobic conditions, low catalytic loading (0.5 mol%), shorter reaction times, broad functional group tolerance and good to excellent isolated yields are some of the significant features of the novel catalytic systems described here. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Reaction of the pentamethylcyclopentadienyl rhodium iodide dimer [Cp*RhI2]2 with 1,1′-diphenyl-3,3′-methylenediimidazolium diiodide in non-alcohol solvents, in the presence of base, led to the formation of bis-carbene complex [Cp*Rh(bis-NHC)I]I (bis-NHC=1,1′-diphenyl-4,4′-methylenediimidazoline-5,5′-diylidene). In contrast, when employing alcohols as the solvent in the same reaction, cleavage of a methylene C−N bond is observed, affording ether-functionalized (cyclometalated) carbene ligands coordinated to the metal center and the concomitant formation of complexes with a coordinated imidazole ligand. Studies employing other 1,1′-diimidazolium salts indicate that the cyclometalation step is a prerequisite for the activation/scission of the C−N bond and, based on additional experimental data, a SN2 mechanism for the reaction is tentatively proposed. [ABSTRACT FROM AUTHOR]

Aims Evaluate the in vitro effect of imidazolium salts ( IMS) on the conidia germination and mycelial growth of Fusarium graminearum and their in vivo efficacy for suppressing the symptoms of the disease and infection of kernels in wheat plants. Methods and Results The minimum inhibitory concentrations ( MIC) of three IMS (C16 MImCl, C16 MImMeS and C16 MIm NTf2) were determined for four F. graminearum isolates using serial broth dilution method. The MICs found for all IMS were either 3·12 or 6·25 μg ml−1 across the isolates, with the former as the most frequent. In the mycelial growth assay on potato dextrose agar media, only the C16 MImCl among the IMS reduced 50% of mycelial growth of one isolate at an estimated concentration of 0·32 mg ml−1. The time-kill curves showed a strong fungicidal effect starting 1 h after incubation at a concentration of 12·5 μg ml−1, representing a fourfold increase in the most frequent MIC. The C16 MImCl sprayed onto the spikes of potted wheat plants during the flowering stage reduced disease intensity at levels comparable to the commercial fungicide when applied preventatively (1 h prior to fungal inoculation), rather than curatively, and at the higher dosage (2 mg ml−1) rather than lower dosage (0·5 mg ml−1). Conclusions C16 MImCl proved to be a potent inhibitor of F. graminearum growth and provided good levels of control of the disease at levels comparable to a commercial fungicide, in wheat plants treated prior to fungal infection during flowering stages. Significance and Impact of the Study This study suggests the potential of using IMS as alternative to the hazardous standard fungicides in the management of Fusarium head blight of wheat. [ABSTRACT FROM AUTHOR]

Weakly coordinating borate or aluminate anions have recently been shown to yield interesting properties of the resulting ionic liquids (ILs). The same is true for large phenyl-substituted imidazolium cations, which can be tuned by the choice, position, or number of substituents on the aromatic ring. We were therefore interested to combine these aryl alkyl imidazolium cations with the weakly coordinating tetrakis((1,1,1,3,3,3-hexafluoropropan-2-yl)oxy)borate [B(hfip)4]¢ anions to study the physical properties and viscosities of these ionic liquids. Despite the large size and high molecular weight of these readily available ILs, they are liquid at room temperature and show remarkably low glass transition points and relatively high decomposition temperatures. [ABSTRACT FROM AUTHOR]

Weakly coordinating borate or aluminate anions have recently been shown to yield interesting properties of the resulting ionic liquids (ILs). The same is true for large phenyl-substituted imidazolium cations, which can be tuned by the choice, position, or number of substituents on the aromatic ring. We were therefore interested to combine these aryl alkyl imidazolium cations with the weakly coordinating tetrakis((1,1,1,3,3,3-hexafluoropropan-2-yl)oxy)borate [B(hfip)4]- anions to study the physical properties and viscosities of these ionic liquids. Despite the large size and high molecular weight of these readily available ILs, they are liquid at room temperature and show remarkably low glass transition points and relatively high decomposition temperatures. [ABSTRACT FROM AUTHOR]

The use of petroleum-derived solvents, particularly volatile organic compounds (VOCs), in the chemical industry has increased the contamination and residual effects of these solvents. Ionic liquids (ILs) can potentially replace VOCs, thereby reducing the risks of environmental contamination and toxicity. In this context, the objectives of this study were as follows: 1 — to obtain an ionic liquid for use in extracting carotenoids from tomatoes with ultrasound assistance; and 2 — to determine the stability and antioxidant activity of tomato carotenoid extracts. Ultrasound can also efficiently extract carotenoid compounds with ionic liquids in comparison with conventional VOC solvents (obtained from an all -trans -lycopene 7.5–8.0 μg·g − 1 tomato sample by IL and 6.2–7.7 μg·g − 1 by acetone). Similarly, the activation energies (E a ) in aqueous medium were obtained for the IL carotenoid extract (10.8 kJ·mol − 1 ) and acetone carotenoid extract (9.4 kJ·mol − 1 ). The antioxidant activities of the tomato carotenoid extract were 7.4 and 12.4 relative to α-tocopherol for the ionic liquid extract and acetone extract, respectively. The combination of chromatographic analysis and degradation kinetics provided data for positive assessment similarity of thermal and light stabilities of tomato carotenoids extracted by IL and extracted by acetone. [ABSTRACT FROM AUTHOR]

Six types of cyclophane-shaped imidazolium salts with planar chirality were synthesized in stereopure forms. The cyclophanes were based on a 2-methylimidazolium unit, the two nitrogen atoms of which were connected by a bridge unit with systematically changed structure. Most salts of the chiral cations with fluorinated imide/amide counter anions existed as ionic liquids from −30 °C to >270 °C, the properties and chirality-recognition ability of which were thoroughly investigated. The imidazolium cation with a hydroxymethyl side chain showed the best chirality-recognition ability and was successfully applied as an NMR enantio-differentiating agent and a chiral stationary phase for gas chromatography. [ABSTRACT FROM AUTHOR]

New water soluble 4,5-bis imidazolium tagged acridines have been synthesized and structurally characterized by multinuclear NMR and single crystal X-ray diffraction techniques. The DNA binding and anti-microbial activities of these acridine derivatives were investigated by fluorescence and far-UV circular dichroism studies. [ABSTRACT FROM AUTHOR]

A series of polysiloxane derivatives having quaternized imidazolium moieties with hydroxyalkyl groups ( [HPIm n OH]X s) (where n is the number of methylene group and X is counter anion) were prepared by quaternization of poly(3-chloropropylmethylsiloxane) ( P1 ) using 1-(ω-hydroxyalkyl)imidazole derivatives ( Im n OH s) and anion-exchange reaction using lithium bis(trifluoromethanesulfonyl)imide. Polysiloxane-based quaternized imidazolium salts having hydroxyalkyl groups with chloride anion ( [HPIm n OH]Cl s) were obtained with high quaternization ratio of approximately 100 mol%. The glass transition temperatures ( T g s) of [HPIm n OH]X s were reduced by introducing a hydroxy group at the end of alkyl groups; however, no significant reduction in T g s was observed by anion exchange from chloride anion to bis(trifluoromethanesulfonyl)imide one (Tf 2 N − ). [ABSTRACT FROM AUTHOR]

The preparative methods for the synthesis of imidazolium and pyridinium room temperature task-specific ionic liquids possessing thiacalix[4]arene complexing groups in cationic or anionic fragments of the molecule are described. The cationic imidazolium and pyridinium derivatives of tetrabuthoxythiacalixarene existing in the conformation 1,3-alternate are capable to bind “soft” metal cations due to cooperative cation-π and ion–dipole interactions with spatially contiguous benzene rings and oxygen atoms of the thiacalixarene platform. The cone-shaped imidazolium salts of the tetrahydroxythiacalix[4]arene sulfonic acid can chelate cations of transition metals, lanthanides, and actinides by oxygen and sulfur atoms at the lower rim of macrocycle. [ABSTRACT FROM PUBLISHER]

Two new homotritopic guests based on tris(benz)imidazolium salts with adamantane binding sites were prepared. NMR and calorimetric titration experiments revealed that each of the three sites independently binds β-cyclodextrin (β-CD) or cucurbit[7]uril (CB7) units to form binary host-guest complexes with 1:3 stoichiometry. The association constants for the single binding site for β-CD and CB7 were determined using titration calorimetry and are in the order of 10 and 10 dm mol, respectively. In addition, both guests were able to form ternary systems with β-CD and CB7 in ratios of 1:1:2 and 1:2:1, respectively. [ABSTRACT FROM AUTHOR]

A series of novel hexahydropyrrolo[2,3- b ]indole–1 H -imidazolium salts were synthesized and evaluated in vitro against a panel of human tumor cell lines. The results suggest that the 5,6-dimethyl-benzimidazole ring, and substitution of the imidazolyl-3-position with a 2-bromobenzyl or 2-naphthylmethyl group, were important for the cytotoxic activity. Notably, Compound 43 , bearing a 2-bromobenzyl substituent at position-3 of 5,6-dimethyl-benzimidazole, was found to possess the most potent derivative against five human tumor cell lines with IC 50 values below 2.68 μM and more selective towards SMMC-7721, A549 and SW480 cell lines. Compounds 25 and 39 were more selective to HL-60 and MCF-7 cell lines with IC 50 values of 0.47 and 1.46 μM. [ABSTRACT FROM AUTHOR]

Being the principal component of biological membranes lipids are essential building blocks of life. Given their huge biological importance, the investigation of lipids, their properties, interactions and metabolic pathways is of prime importance for the fundamental understanding of living cells and organisms as well as the emergence of diseases. Different strategies have been applied to investigate lipid-mediated biological processes, one of them being the use of lipid mimetics. They structurally resemble their natural counterparts but are equipped with functionality that can be used to probe or manipulate lipid-mediated biological processes and biomembranes. Lipid mimetics therefore constitute an indispensable toolbox for lipid biology and membrane research but also beyond for potential applications in medicine or synthetic biology. Herein, we highlight recent advances in the development and application of lipid-mimicking compounds. [Display omitted] [ABSTRACT FROM AUTHOR]

The nickel-catalyzed direct reductive cross-coupling of aryl halides with readily accessible polysubstituted allyl halides provides an efficient method for preparing diverse allylated arenes under mild conditions. Both allyl bromides and allyl chlorides are compatible with the transformation. [ABSTRACT FROM AUTHOR]

In this study, the selective extraction and stripping conditions of Co(II) from acidic thiocyanate solution containing Co(II) and Ni(II) by ionic-liquid-based solvent-extraction technique using symmetric and asymmetric imidazolium bromide salts substituting butyl and isobutyl groups were experimentally optimized. The molecular structure effect of imidazolium bromide salts (IMs) have been determined as main factor to extract Co(II). The executive parameters on stripping and extraction processes, such as IMs concentration, pH, thiocyanate concentration, stripping reagent type, and concentration, were experimentally investigated. Molecular variation of organometalic complex (adduct) consisting of IMs and Co-SCN, were illuminated by comparision of ATR-FTIR spectrums of pure and Co-SCN loaded IMs. Stoichiometric rates of the adduct was verified with slope analysis. In light of these examinations, Co(SCN)3−has been determined as prominent Co-SCN species in aqueous media. Symetric IMs were identified as more effective than asymmetric ones on selective separation of Co(II) from Ni(II). Under optimum conditions, 99.20% of Co(II) was extracted and 93.33% of Co(II) was recovered with higher separation factors especially in diluted solution, whereas, Ni(II) extractions were negligible. We have concluded that the separation power of this study is high in Co(II)/Ni(II) containing dilute solutions and it can be used in preconcentration purposes effectively. [ABSTRACT FROM AUTHOR]

Imidazolium salts have antitumor potential and toxicological effects on various microorganisms. The authors' aim is to synthesize a new imidazolium salt and to assess its pharmacokinetic and antitumor potentials by in vitro and in vivo studies. In this study, bis(trifluoromethanesulfonyl) imide (ITFSI) was synthesized and labeled with (131)I using the iodogen method. The efficiency of radiolabeling was determined with high yield (95.5% ± 3.7%). Pharmacokinetic properties of the compound were investigated in albino Wistar rats using radiolabeled compound. The radiolabeled compound ((131)I-ITFSI) has been stable during a period of 3 hours in human serum. The uptake of (131)I-ITFSI reached maximum in the spleen, liver, and blood at 60 minutes, large intestine and heart at 30 minutes, and ovary at 120 minutes. It is observed that intracellular uptake of the radiolabeled compound is higher in the CaCo-2 (colon adenocarcinoma tumor) cell line than HEK-293 (human epithelial kidney) cell line. In further study, antitumor potential of ITFSI on a colon adenocarcinoma tumor-bearing animal model may be investigated. [ABSTRACT FROM AUTHOR]

A rapid, highly efficient and mild green synthesis of benzoin was performed using substituted benzaldehyde catalyzed by KCN and imidazolium salts in EtOH/H 2 O under ultrasonic activation. The products were obtained in good yields within short reaction times with N , N ′-dialkylimidazolium salts, which were found to be more effective pre-catalysts at room temperature for benzoin condensation in comparison to corresponding cyanide ion in heating method. This simple method affords benzoin derivatives at room temperature in short reaction times with high yield and purity. [ABSTRACT FROM AUTHOR]

The supramolecular aggregation of three diimidazolium-functionalized perylene bisimides, differing in the alkyl chain length was investigated. These salts form aggregates in solvents like chloroform, dichloromethane, and glycerol. Solvent-, concentration-, and temperature-dependent spectroscopic studies were carried out, evidencing the occurrence of an isodesmic, enthalpy-driven aggregation process, underpinned by π-π stacking and hydrogen bonding. Moreover, dynamic light scattering (DLS) measurements and SEM images revealed that these salts aggregate in chloroform into elongated structures. [ABSTRACT FROM AUTHOR]

Aims To investigate the antidermatophytic action of a complementary set imidazolium salts (IMS), determining structure-activity relationships and characterizing the IMS toxicological profiles. Methods and Results The susceptibility evaluation of 45 dermatophytic clinical isolates, treated in vitro with eleven different IMS (ionic compounds) and commercial antifungals (nonionic compounds), was performed by broth microdilution, following the standard norm of CLSI M38-A2. All dermatophytes were inhibited by IMS, where the lowest minimum inhibitory concentration (MIC) values were observed for salts with n-hexadecyl segment in the cation side chain, containing either the chloride or methanesulfonate anion. 1- n-Hexadecyl-3-methylimidazolium chloride (C16MImCl) and 1- n-hexadecyl-3-methylimidazolium methanesulfonate (C16MImMeS) acted as fungicides, even in extremely low concentrations, wherein C16MImMeS exerted this effect on 100% of the tested dermatophytes. Some of these IMS provoked evident alterations on the fungi cell morphology, causing a total cell damage of ≥70%. Importantly, none of the screened IMS were cytotoxic, mutagenic or genotoxic to human leucocyte cells. Conclusions This report demonstrates for the first time the strong antifungal potential of IMS against multidrug-resistant dermatophytes, without presenting toxicity to human leucocyte cells at MIC. Significance and Impact of the Study The expressive antifungal activity of IMS, combined with the in vitro nontoxicity, makes them promising compounds for the safe and effective treatment of dermatophytoses, mainly when this skin mycosis is unresponsive to conventional drugs. [ABSTRACT FROM AUTHOR]

The formation, stabilisation and reactivity of contact ion pairs of non-protic imidazolium ionic liquids (ILs) in solution are conceptualized in light of selected experimental evidence as well theoretical calculations reported mainly in the last ten years. Electric conductivity, NMR, ESI-MS and IR data as well as theoretical calculations support not only the formation of contact ion pairs in solution, but also the presence of larger ionic and neutral aggregates even when dissolved in solvents with relatively high dielectric constants, such as acetonitrile and DMSO. The presence of larger imidazolium supramolecular aggregates is favoured at higher salt concentrations in solvents of low dielectric constant for ILs that contain shorter N-alkyl side chains associated with anions of low coordination ability. The stability and reactivity of neutral contact species are also dependent on the nature of the anion, imidazolium substituents, and are more abundant in ILs containing strong coordinating anions, in particular those that can form charge transfer complexes with the imidazolium cation. Finally, some ILs display reactivities as contact ion pairs rather than solvent-separated ions. [ABSTRACT FROM AUTHOR]

The aim of the paper is the selective extraction and stripping of Cd(II) from acidic iodide solutions containing Cd(II) and Ni(II) by liquid–liquid solvent extraction technique using synthesized and characterized imidazolium salts as carriers, which are 3-butyl-1-methyl-1H-imidazol-3-ium bromide (IM1), 1,3-dibutyl-1H-midazol-3-ium bromide (IM2), 3-isobutyl-1-methyl-1H-imidazol-3-ium bromide (IM3), 1,3-diisobutyl-1H-midazol-3-ium bromide (IM4), in dichloromethane. The important parameters affecting extraction and stripping behavior of Cd(II) were studied experimentally. Complex formation and its stoichiometric rate between IMs and CdI 4 2− was explained with comparison of ATR-FTIR spectrums of pure and CdI 4 2− (aq) loaded IMs and slope analysis. According to these evaluations, the adduct formation was confirmed as IM 2 CdI 4(org) . In the light of obtained results, the symmetric IMs substituting n -butyl group on nitrogen atoms have been determined as the best appropriate IMs to transport of Cd(II). Under optimum conditions, 99.24% of Cd(II) has been extracted from acidic iodide solution containing 500 mg/L of Cd(II) and Ni(II). Ni(II) extraction percentages were observed as negligible throughout experiments. The extraction selectivity of Cd(II) over the other metal ion impurities has been identified in the order β Cd/Ni > β Cd/Co > β Cd/Zn > β CdCu . [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM PUBLISHER]

The reaction of nickel(II) acetylacetonate trimer with 1,3-bis(2,4,6-trimethylphenyl)imidazolium chloride, [IMesH]Cl, leads to the formation of the remarkable double salt [IMesH] 2 [NiCl 4 ]·[IMesH]Cl 2 , (or alternatively [IMesH] 3 [NiCl 4 ]Cl). The solid-state structure of this species was determined by a single X-ray diffraction study. The molecular parameters of the ions are unremarkable, but this double salt crystallizes in the chiral space group P6 3 despite the achiral nature of all the ions: the chirality arises from the helical arrangement of the imidazolium mesityl groups. Additionally, the crystal contains hydrophobic channels of ca. 4.5 Å diameter, and there are extensive H-bonding interactions in the crystal. The double salt reacts with potassium tert -butoxide to give the known bis -N-heterocyclic carbene complex trans -[Ni(IMes) 2 Cl 2 ], 3 . [ABSTRACT FROM AUTHOR]

Two 1-alkyl-3-methylimidazolium trifluoromethanesulfonate, [C x MIM] [TfO] (x = 12 or 20), form in appropriate solvents liquid crystal phases from which crystals can be obtained. The cohesion of this crystal is ensured by a combination of dispersion forces, H-bonds and electrostatic interactions developed firstly in the liquid crystal phase. [ABSTRACT FROM AUTHOR]

A group of homochiral imidazolium salts bearing hydrophobic camphor derived moiety and ester or amide functional group were synthesized and characterized. The novel imidazolium bromides were tested as antimicrobial and antifungal agents and their minimal inhibitory concentration (MIC) was evaluated and compared to clinically used benzalkonium bromide (BAB) and carbethopendecinium bromide. The MIC values of amide derivatives 2a and 2b were slightly smaller than those for BAB, indicating their good activity. None of the prepared salts was more effective than carbethopendecinium bromide. The biocidal efficacy of amide derivatives was much higher compared to the ester analogues. [ABSTRACT FROM AUTHOR]

Schiff base palladacycles readily reacted with N -heterocyclic carbenes (NHCs) after deprotonation of the corresponding imidazolium salts with K[N(SiMe 3 ) 2 ] to give mononuclear cyclometallated complexes in which the NHC was coordinated trans to the imine nitrogen. The reaction of dinuclear acetate-, 1 , or chloro-bridged, 2 , 3 , complexes gave new mononuclear species, 4 – 9 , after the bridge-splitting reaction, inclusive of acetato/chloride exchange during the purification process. Treatment of the terdentate [ C , N , N ] metallacycles, 10 , 11 , with the NHCs gave 12 – 15 with substitution of the chloro or acetato ligands; the Pd–NMe 2 bond remains uncleaved. Reaction of the carbene ligands with the tetranuclear palladacycle, 16 , gave 17 – 20 , after splitting of the parent structure, but without ring opening of neither the Pd–N nor of the Pd–O bonds, hence retaining the metallated and coordination rings at the metal. The structures of 6 , 7 and 19 have been determined by single crystal X-ray diffraction. [ABSTRACT FROM AUTHOR]

Thermolytic decomposition of 3,3'-(ethan-1,2-diyl)bis(1-methyl-1 H-imidazolium) bis-(hexafluorophosphate) ( 1) under reduced pressure results in a 1: 1 mixture of pentafluo-ro(1-ethenyl-3-methyl-2,3-dihydro-1 H-imidazole-2-ylidene-κ C)phosphorous ( 2) and penta- fluoro(3-methyl-1 H-imidazole-κ N)phosphorous ( 3) in an almost quantitate yield. Products 2 and 3 were isolated as individual compounds by fractional recrystallization from hot methanol. Direct observation of a 1: 1 co-crystallite of 2-pentafluorophosphanyl-1-ethenyl-3-methyl-1 H-imidazolium hexafluorophosphate and adduct 2 (compound 5) as a minor coproduct of this reaction reveals a complicated path of the thermolysis. Crystal and molecular structures of compounds 2, 3, and 5 were established by X-ray diffraction analysis. Compound 2 presents the first example of an N-alkenyl substituted Arduengo carbene adduct with a main Group element Lewis acid. Compound 3 presents the second known organic base N-adduct with PF. [ABSTRACT FROM AUTHOR]

A straightforward reaction between 1,3-dimethyl-1 H-imidazolium iodide ( 1) and AgF in acetonitrile (molar ratio 2: 3) results in bis[1,3-dimethyl-2,3-dihydro-1 H-imidazol-2-ylidene-κ C]silver(1+) hydrofluorides ( 2) and AgI in an almost quantitative yield. Hydrofluorides 2, namely, [(CHN)Ag][HF] ( 2a) and [(CHN)Ag][HF] ( 2b), were isolated under different crystallization conditions. Crystal and molecular structures of hydrofluorides 2a and 2b as well as that of the initial salt 1 were established by X-ray diffraction analysis. [ABSTRACT FROM AUTHOR]

Abstract: Novel C2-substituted imidazolium-based cross-linked anion exchange membranes (AEMs) are prepared via irradiation with ultraviolet light cross-linking of styrene, acrylonitrile and 1,3-diallyl-2-methyl imidazolium bromine ([DAMIm][Br]), and followed by anion exchange with hydroxide ions. [DAMIm][Br] is synthesized and used both as crosslinker and hydrophilic phase. The ionic conductivity of the AEMs increases with increasing [DAMIm][Br] content due to the hydrophilic regions and the continuous hydrophilic polymeric networks formed in the membranes. The imidazolium-based cross-linked AEMs show excellent thermal stabilities, and the membrane which containing 30% mass fraction of [DAMIm][Br] shows ionic conductivity up to 2.0 × 10−2 S cm−1 and good long-term chemical stability in 1 M KOH solution. The results of this study suggest that the C2-substituted imidazolium-based cross-linked AEMs have good perspectives for alkaline fuel cell applications. [Copyright &y& Elsevier]

A series of novel 1-((indol-3-yl)methyl)–1 H -imidazolium salts were prepared and evaluated in vitro against a panel of human tumor cell lines. The results suggest that the 5,6-dimethyl-benzimidazole ring, and substitution of the imidazolyl-3-position with a naphthylacyl or 4-bromophenacyl group, were vital for modulating inhibitory activity of cell growth. In particular, 1-(( N -Boc-indol-3-yl)methyl)-3-(2-naphthylacyl)-1 H -5,6-dimethyl-benzimidazolium bromide was found to be the most potent derivative and more selective against myeloid liver carcinoma (SMMC-7721), lung carcinoma (A549) and breast carcinoma (MCF-7), with IC 50 values 1.9-fold, 1.7-fold and 4.8-fold lower than DDP. This compound can induce significant cell apoptosis in SMMC-7721 cells. [ABSTRACT FROM AUTHOR]

Four N-functionalized imidazole derivatives with a-amino acid residues were prepared and subsequently used for the construction of ten new optically pure imidazolium ionic liquids. The prepared imidazolium salts comprise three derivatives bearing one a-amino acid residue, five derivatives with two residues, and two derivatives possessing two bridged imidazolium ions. The molecular structure of one N-substituted imidazole was also confirmed by X-ray crystal structure analysis. Iodide and (di)bromide ions in five representative imidazolium salts were replaced with tetrafluoroborate ion in an attempt to lower the melting temperatures of these salts. In general, the properties of all target imidazolium ionic liquids could easily be tuned by N1/N3-substitution and the counterion used. [ABSTRACT FROM AUTHOR]

A series of poly(arylene ether sulfone) containing bulky imidazole groups (PSf-Im-x) have been successfully synthesized based on a novel monomer 2,2'-bis-(2-ethyl-4-methyl-imidazole-1-ylmethyl)-biphenyl-4,4'-diol (EMIPO). After quaternized by n-bromobutane, these polymers are evaluated for alkaline anion exchange membranes (AEMs). The functional group, 2-ethyl-3-butyl-4-methyl-imidazolium, is employed in these new polymers for reason that attaching bulky groups around the imidazolium ring reduces the access of OH- to imidazolium, which enhances the alkaline stability of the membranes. The membrane with an IEC value of 2.07 possesses ionic (OH-) conductivity of 0.014Scm-1 at 30°C and 80% of the ionic conductivity is maintained after treatment in 1M KOH at 60°C for 144h. [ABSTRACT FROM AUTHOR]

Abstract: Hepatocellular carcinoma (HCC) is one of the most commonly diagnosed lethal cancers in the world. We previously showed two imidazolium salts (IBN-1 and IBN-9) with a moderate efficacy for HCC. Here we report a more potent imidazolium compound IBN-65 (1-benzyl-2-phenyl-3-(4-isopropyl)-benzyl-imidazolium chloride) and the associated mechanisms of action in a mouse model of HCC. The IC50 of this compound in various liver cancer cell lines was around 5 μm. IBN-65 dose-dependently arrested cell cycle at G1 phase and was associated with the down-regulation of the cyclin-dependent kinase-4, -6, cyclin D1, and cyclin E. In addition, IBN-65 induced apoptosis by down-regulating Survivin, Bcl-2 and up-regulating Bax, leading to sequential activation of Caspase-3, Caspase-9 and the cleavage of poly(ADP-ribose) polymerase (PARP). Dysregulation of the epidermal growth factor receptor (EGFR) signaling network has been frequently reported in HCC. We found that IBN-65 displayed a profound inhibitory effect on the EGFR/Raf/MEK/ERK signaling at the phosphorylation level. In Huh7 or Hep3B cells, pretreatment with IBN-65 attenuated EGF-induced phosphorylation of both EGFR and the downstream p44/42 MAPK. A siRNA knockdown of EGFR also proved that IBN-65 induced apoptosis mostly through inhibiting downstream EGFR pathway signaling, much less at the receptor level. Infrequent administration of IBN-65 (i.p., 5 mg/kg once weekly for four weeks) to mice bearing the Huh7 cells significantly reduced the tumor volume by 65% without affecting the body weight. Critically, many of the anti-tumor signaling features observed in the HCC cell lines were recaptured in the xenografted tissues. Thus, the metal-free imidazolium compound IBN-65 could be a potential candidate towards therapeutic development for HCC. [Copyright &y& Elsevier]

We describe the molecular parameters governing the transmembrane activity of imidazolium-functionalized anion transporters and present a detailed mechanistic study. These ionophores adopt a mobile-carrier mechanism for short methyl and butyl chains, a combined mobile-carrier/transmembrane-pore mechanism for octyl and dodecyl chains, and form transmembrane aggregates for hexadecyl chains. [ABSTRACT FROM AUTHOR]

Reactions of symmetrically and non-symmetrically substituted nitrile-functionalized imidazolium salts (1–3) with silver(I) oxide in methanol at room temperature afforded complexes (4–6) of the type [NHC-Ag-NHC]PF6, (NHC: imidazol-2-ylidene). All reported compounds have been characterized by spectral (1H, 13C NMR and FTIR) and elemental analysis. The structure of bis-imidazolium salt 3 and silver complex 4 was unambiguously elucidated by the single-crystal X-ray diffraction method. The effect of substitutions on the anticancer activity of compounds 1–6 has been investigated by in vitro cytotoxicity studies against human colorectal (HCT 116) cancer cell line, using the MTT assay method. All three silver complexes (4–6) displayed promising anticancer activity with IC50 values of 6.0±0.2, 14.0±0.6 and 4.0±0.2μM, while imidazolium salts, 1–3, showed least (>200μM) to moderate (20.3±0.2 and 95.0±2μM) anticancer potential, respectively. Bis-imidazolium salt 3 and binuclear complex 6 displayed good activity against human breast (MCF-7) cancer line with IC50 values of 82.4±2.5 and 0.9±0.4μM, respectively. [ABSTRACT FROM AUTHOR]

Alpha,omega-bis(pyrazol-1-yl)alkanes and alpha,omega-bis(imidazol-1-yl)alkanes with spacers consisting of four to ten methylene groups have been prepared from pyrazole, 3,5-dimethylpyrazole or imidazole and corresponding dibromoalkanes in a superbasic medium KOH-DMSO. The proposed method of synthesis allowed the preparation of new flexible bidentate ligands without the need to use toxic solvents and tedious workup procedures. Bis(pyrazol-1-yl)alkanes were further functionalized for their use as precursors for “non-classical” mesoionic N-heterocyclic carbene ligands. One the first step, iodine atoms were introduced to positions 4 of pyrazole rings by oxidative iodination using I 2 -HIO 3 system. On the next step, nitrogen atoms in positions 2 of pyrazole rings were alkylated using several agents. Reaction with methyliodide unexpectedly led to the formation of only mono-alkylated products even after 7 days of refluxing in a neat alkyliodide. Methylation by trimethyloxonium tetrafluoroborate or methyltriflate led to dimethylated products in high yields. Bis(imidazol-1-yl)alkanes were easily alkylated by methyliodide to give di(imidazolium) salts – precursors to “classic” N-heterocyclic dicarbenes. [ABSTRACT FROM AUTHOR]

Abstract: A series of phosphino-imidazolium salts (1–4), which are composed of the phosphine-incorporated imidazolium cations and the corresponding counter-anions of PF6 −, TfO−, and BF4 −, are used in Rh-catalyzed hydroformylation. It was found that when the ionic Rh(III)-complex (1A, [RhIIICl4(L)2]PF6, L =1-butyl-2-diphenylphosphino-3-methylimidazolium) was used as the pre-catalyst for hydroformylation of 1-octene, its inert catalytic activity could be efficiently tailored by the ion-pair synergetic effect of ligand 1–4 in water suspension. The single crystal structures of 1, 2, and 4 indicate that the hydrogen bonding network is developed between the cation and anion of ion-pairs 1 and 4, but is completely non-inexistent in 2. [Copyright &y& Elsevier]