cas 33529-01-0, 1-hexylimidazole | Articles data

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N-Functionalised Imidazoles as Stabilisers for Metal Nanoparticles in Catalysis and Anion Binding
Metal nanoparticles (NPs) have physicochemical properties which are distinct from both the bulk and molecular metal species, and provide opportunities in fields such as catalysis and sensing. NPs typically require protection of their surface to impede aggregation, but these coatings can also block access to the surface which would be required to take advantage of their unusual properties. Here, we show that alkyl imidazoles can stabilise Pd, Pt, Au, and Ag NPs, and delineate the limits of their synthesis. These ligands provide an intermediate level of surface protection, for which we demonstrate proof-of-principle in catalysis and anion binding.
Beer, Paul D.,Cookson, James,Serpell, Christopher J.
p. 683 - 690
(2020)
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Structure and properties of N, N-alkylene bis(Na?2-alkylimidazolium) salts
A series of N,N-alkylene bis(Na?2-alkylimidazolium) salts with various anions was prepared and characterized. The hydrogen-bonding abilities and ion-pairing strengths of the salts in solution were varied by changing the solvent and anion. Qualitatively, the extent of ion pairing of the 1,2-bis[N-(Na?2-butylimidazolium)]ethane salts with different anions was determined in acetone-d6 by 1H NMR spectroscopy. Thermal properties of the imidazolium salts were related not only to the nature of anions but also to the spacer length between imidazolium cations. Exceptionally high melting points of 1,2-bis[N-(Na?2-alkylimidazolium)]ethane bis(hexafluorophosphate)s can be explained by multiple hydrogen bonds observed in the X-ray crystal structures. Moreover, a trans conformation of the ethylene spacer of 1,2-bis[N-(Na?2-alkylimidazolium)]ethane bis(hexafluorophosphate)s allows good stacking structure in the crystals. ? 2010 American Chemical Society.
Lee, Minjae,Niu, Zhenbin,Slebodnick, Carla,Gibson, Harry W.
p. 7312 - 7319
(2010)
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Thermo-solvatochromism in binary mixtures of water and ionic liquids: On the relative importance of solvophobic interactions
The thermo-solvatochromism of 2,6-dibromo-4-[(E)-2-(1-methylpyridinium-4- yl)ethenyl] phenolate, MePMBr2, has been studied in mixtures of water, W, with ionic liquids, ILs, in the temperature range of 10 to 60 °C, where feasible. The objectives of the study were to test the applicability of a recently introduced solvation model, and to assess the relative importance of solute-solvent solvophobic interactions. The ILs were 1-allyl-3-alkylimidazolium chlorides, where the alkyl groups are methyl, 1-butyl, and 1-hexyl, respectively. The equilibrium constants for the interaction of W and the ILs were calculated from density data; they were found to be linearly dependent on NC, the number of carbon atoms of the alkyl group; van't Hoff equation (log K versus 1/T) applied satisfactorily. Plots of the empirical solvent polarities, ET (MePMBr2) in kcal mol-1, versus the mole fraction of water in the binary mixture, χw, showed non-linear, i.e., non-ideal behavior. The dependence of ET (MePMBr2) on χw, has been conveniently quantified in terms of solvation by W, IL, and the "complex" solvent IL-W. The non-ideal behavior is due to preferential solvation by the IL and, more efficiently, by IL-W. The deviation from linearity increases as a function of increasing NC of the IL, and is stronger than that observed for solvation of MePMBr2 by aqueous 1-propanol, a solvent whose lipophilicity is 12.8 to 52.1 times larger than those of the ILs investigated. The dependence on NC is attributed to solute-solvent solvophobic interactions, whose relative contribution to solvation are presumably greater than that in mixtures of water and 1-propanol.
Sato, Bruno M.,De Oliveira, Carolina G.,Martins, Clarissa T.,El Seoud, Omar A.
p. 1764 - 1771
(2010)
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Preparation method of nitrogen-alkyl (deuterated alkyl) aromatic heterocycle and alkyl (deuterated alkyl) aryl ether compound
The invention provides a method for preparing nitrogen-alkyl(deuterated alkyl)aromatic heterocycle and alkyl(deuterated alkyl)aryl ether compounds. The method adopted in the invention specifically comprises the following steps: firstly, adding an alkoxy base (MOR') or a combination reagent Q (comprising a base M'X, an alcohol C and a molecular sieve E) into a solvent B to be stirred; then, addingan aromatic compound D of nitrogen sulfonyl or oxygen sulfonyl into a mixture; separating and purifying after reaction to obtain nitrogen-alkyl(deuterated alkyl)aromatic heterocycle or alkyl(deuterated alkyl)aryl ether. The method can realize one-step conversion from an electron withdrawing benzenesulfonyl protecting group on a nitrogen or oxygen atom to an electron donating alkyl protecting group, avoids using highly toxic alkyl halide, and has advantages of being efficient, economical, environmentally friendly, mild in condition, good in substrate universality and high in yield; the prepareddeuterated compounds can be widely applied to the fields of pharmaceutical chemistry and organic chemistry synthesis.
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Paragraph 0099-0103; 0105

(2021/04/03)

A Remarkable Fluorescence Quenching Based Amplification in ATP Detection through Signal Transduction in Self-Assembled Multivalent Aggregates
Signal transduction is essential for the survival of living organisms, because it allows them to respond to the changes in external environments. In artificial systems, signal transduction has been exploited for the highly sensitive detection of analytes. Herein, a remarkable signal transduction, upon ATP binding, in the multivalent fibrillar nanoaggregates of anthracene conjugated imidazolium receptors is reported. The aggregates of one particular amphiphilic receptor sensed ATP in high pm concentrations with one ATP molecule essentially quenching the emission of thousands of receptors. A cooperative merging of the multivalent binding and signal transduction led to this superquenching and translated to an outstanding enhancement of more than a millionfold in the sensitivity of ATP detection by the nanoaggregates; in comparison to the “molecular” imidazolium receptors. Furthermore, an exceptional selectivity to ATP over other nucleotides was demonstrated.
Biswas, Rakesh,Naskar, Sumit,Ghosh, Surya,Das, Mousumi,Banerjee, Supratim
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p. 13595 - 13600
(2020/10/06)

Inhibition of bacterial growth and galactosyltransferase activity of WbwC by α, ω-bis(3-alkyl-1H-imidazolium)alkane salts: Effect of varying carbon content
A series of compounds was designed and synthesized having two imidazolium rings separated by a polymethylene spacer and having alkyl substituents on each of the imidazolium rings. The compounds were assayed for their effects on the activity of galactosyltransferase WbwC, and also on the growth of Gram-negative and Gram-positive bacteria, as well as human cells. The inhibition observed on enzyme activities and cell growth was dependent on the total number of carbons in the spacer and the alkyl substituents on the imidazolium rings. These readily synthesized, achiral compounds have potential as antimicrobial and antiseptic agents.
Brockhausen, Inka,Kocev, Alexander,Kong, Xianqi,Melamed, Jacob,Szarek, Walter A.,Vlahakis, Jason Z.,Wang, Shuo,Xu, Yaozu
(2020/04/21)

Detosylative (Deutero)alkylation of Indoles and Phenols with (Deutero)alkoxides
An efficient strategy for N/O-(deutero)alkylation of indoles and phenols with alkoxides/alcohols as the alkylation reagents is described. The consecutive detosylation/alkylation transformations feature mild reaction conditions, high ipso-selectivity, and good functional group tolerance (>50 examples). A one-pot selective N-alkylation of unprotected indoles with alcohols and TsCl is also realized. The application of this method is demonstrated by the introduction of isotope-labeled (CD3 and 13CH3) groups using the readily accessible labeled alcohols and the synthesis of pharmaceuticals.
Zhu, Ming-Hui,Yu, Cheng-Long,Feng, Ya-Lan,Usman, Muhammad,Zhong, Dayou,Wang, Xin,Nesnas, Nasri,Liu, Wen-Bo
supporting information
p. 7073 - 7077
(2019/09/30)

Highly-efficient N-arylation of imidazole catalyzed by Cu(II) complexes with quaternary ammonium-functionalized 2-acetylpyridine acylhydrazone
The reaction of (E)-N,N,N-trimethyl-2-oxo-2-(2-(1-(pyridin-2-yl)ethylidene)hydrazinyl)ethan-1-aminium-chloride (HLCl) with copper(II) perchlorate led to mononuclear [CuLCl]ClO4 complex (1). The same reaction with excess of sodium azide gives di
Milenkovi?, Milica R.,Papastavrou, Argyro T.,Radanovi?, Du?anka,Pevec, Andrej,Jagli?i?, Zvonko,Zlatar, Matija,Gruden, Maja,Vougioukalakis, Georgios C.,Turel, Iztok,An?elkovi?, Katarina,?obelji?, Bo?idar
p. 22 - 30
(2019/03/26)

Novel alkylimidazolium ionic liquids as an antibacterial alternative to pathogens of the skin and soft tissue infections
Keeping in mind the concept of green chemistry, this research aims to synthesize and characterize new ionic liquids (ILs) derived from N-cinnamyl imidazole with different sizes of alkyl chains (1, 6, 8, and 10 carbon atoms), and evaluate their antibacterial activity against Skin and soft tissue infections (SSTIs) causative bacteria. The antibacterial screening was carried out by agar well diffusion and the Minimum Inhibitory Concentration (MIC) and Half Maximum Inhibitory Concentration (IC50) of the different ILs were determined by microdilution in broth, also Molecular dynamics simulations were performed to study the interaction mechanism between ILs and membranes. The MIC value in Gram-positive bacteria showed that as the hydrocarbon chain increases, the MIC value decreases with a dose-dependent effect. Furthermore, Gram-negative bacteria showed high MIC values, which were also evidenced in the antibacterial screening. The molecular dynamics showed an incorporation of the ILs with the longer chain (10 C), corresponding to a passive diffusion towards the membrane surface, for its part, the ILs with the shorter chain due to its lack of hydrophobicity was not incorporated into the bilayer. Finally, the new ILs synthesized could be an alternative for the treatment of Gram-positive bacteria causative of SSTIs.
Doria, Oscar Forero,Castro, Ricardo,Gutierrez, Margarita,Valenzuela, Diego Gonzalez,Santos, Leonardo,Ramirez, David,Guzman, Luis
(2018/09/26)

Halogen-bond driven self-assembly of triangular macrocycles
2-Iodoethynylpyridine and 2-iodoethynyl-1-methyl-imidazole self-assemble under halogen-bonding control into discrete macrocycles, viz. supramolecular triangles.
Szell, Patrick M. J.,Siiskonen, Antti,Catalano, Luca,Cavallo, Gabriella,Terraneo, Giancarlo,Priimagi, Arri,Bryce, David L.,Metrangolo, Pierangelo
supporting information
p. 10467 - 10471
(2018/07/05)

A planar anthracene–imidazolium/anthracene–benzimidazolium cation system in a spherical polyoxometalate matrix: Synthesis, crystallography and spectroscopy
A series of ion–pair compounds, comprising of Lindqvist type isopolyanions viz., [Mo6O19]2?and [W6O19]2?as the counter anions and anthracene–imidazolium/anthracene–benzimidazolium as counter cations, have been described. Structures of the isolated stoichiometric solids have been unambiguously determined by single crystal X-ray diffraction analysis. In spite of the structural incompatibility between anthracene (planar) and the present polyoxometalate anions (spherical), coulombic and several intermolecular weak interactions, e.g. C–H?O, C–H?π, π–π, etc. compensate the destabilization energy raised due to presence of the structurally mis-matched components in the respective crystal lattices. Single-crystal- as well as powder X-ray-diffraction (PXRD) analyses reveal iso-structural relationship between the hexamolybdates- and hexatungstates-associated ion pair compounds. Conformational variation has been observed in the crystal structures containing benzyl benzimidazolium counter cations. Diffuse reflectance electronic absorption spectral studies are performed to understand the relatively intense color of the title compounds in their solid states in comparison to their respective solution states.
Chatterjee, Tanmay,Kumar, N. Tanmaya,Das, Samar K.
p. 68 - 83
(2017/03/01)

Anticancer Activity of Polyoxometalate-Bisphosphonate Complexes: Synthesis, Characterization, in Vitro and in Vivo Results
We synthesized a series of polyoxometalate-bisphosphonate complexes containing MoVIO6 octahedra, zoledronate, or an N-alkyl (n-C6 or n-C8) zoledronate analogue, and in two cases, Mn as a heterometal. Mo6L2 (L = Zol, ZolC6, ZolC8) and Mo4L2Mn (L = Zol, ZolC8) were characterized by using single-crystal X-ray crystallography and/or IR spectroscopy, elemental and energy dispersive X-ray analysis and 31P NMR. We found promising activity against human nonsmall cell lung cancer (NCI-H460) cells with IC50 values for growth inhibition of ～5 μM per bisphosphonate ligand. The effects of bisphosphonate complexation on IC50 decreased with increasing bisphosphonate chain length: C0 ≈ 6.1×, C6 ≈ 3.4×, and C8 ≈ 1.1×. We then determined the activity of one of the most potent compounds in the series, Mo4Zol2Mn(III), against SK-ES-1 sarcoma cells in a mouse xenograft system finding a ～5× decrease in tumor volume than found with the parent compound zoledronate at the same compound dosing (5 μg/mouse). Overall, the results are of interest since we show for the first time that heteropolyoxomolybdate-bisphosphonate hybrids kill tumor cells in vitro and significantly decrease tumor growth, in vivo, opening up new possibilities for targeting both Ras as well as epidermal growth factor receptor driven cancers.
Boulmier, Amandine,Feng, Xinxin,Oms, Olivier,Mialane, Pierre,Rivière, Eric,Shin, Christopher J.,Yao, Jiaqi,Kubo, Tadahiko,Furuta, Taisuke,Oldfield, Eric,Dolbecq, Anne
supporting information
p. 7558 - 7565
(2017/07/12)

A Comprehensive Study on the Synthesis and Micellization of Disymmetric Gemini Imidazolium Surfactants
Two groups of disymmetric Gemini imidazolium surfactants, [C14C4Cmim]Br2 (m?=?10, 12, 14) and [CmC4Cnim]Br2 (m?+?n?=?24, m?=?12, 14, 16, 18) surfactants, were synthesized and their structures were confirmed by 1H NMR and ESI–MS spectroscopy. Their adsorption at the air/water interface, thermodynamic parameters and aggregation behavior were explored by means of surface tension, electrical conductivity and steady-state fluorescence. A series of surface activity parameters, including cmc, γcmc, πcmc, pC20, cmc/C20, Γmax and Amin, were obtained from surface tension measurements. The results revealed that the overall hydrophobic chain length (Nc) for [C14C4Cmim]Br2 and the disymmetry (m/n) for [CmC4Cnim]Br2 had a significant effect on the surface activity. The cmc values decreased with an increase of Nc or m/n. The thermodynamic parameters of micellization (ΔGm θ, ΔHm θ, ΔSm θ) derived from the electrical conductivity indicated that the micellization process of [C14C4Cmim]Br2 and [CmC4Cnim]Br2 was entropy-driven at different temperatures, but the contribution of ΔHm θ to ΔGm θ was enhanced by increasing Nc or m/n. The micropolarity and micellar aggregation number (Nagg) were estimated by steady-state fluorescence measurements. The results showed that the surfactant with higher Nc or m/n can form larger micelles, due to a tighter micellar structure.
Zhao, Xiaohui,An, Dong,Ye, Zhiwen
p. 681 - 691
(2016/07/06)

Synthesis of methylal from methanol and formaldehyde catalyzed by Br?nsted acid ionic liquids with different alkyl groups
The catalytic reaction of methanol with formaldehyde for the preparation of methylal was investigated in various Br?nsted acid ionic liquids with different carbon chain length of alkyl groups. The structures, acidities, and properties of ionic liquids were experimentally characterized and theoretically analyzed. The Br?nsted acidity-viscosity-activity correlation for the ionic liquids was studied. Among all these ionic liquids, [C6ImBS][HSO4] exhibited the best catalytic performance, which was ascribed to its strong Br?nsted acidity and low viscosity. The catalytic activity of the ionic liquid was near that of concentrated sulfuric acid. The influences of ionic liquid dosage, reaction temperature and molar ratio of methanol to formaldehyde were explored using [C6ImBS]HSO4 as the catalyst. Under the optimal conditions of n(methanol):n(formaldehyde):n(ILs) = 2.5:1:0.0258, 60 °C, and 4 h, the conversion of formaldehyde can reach 63.37%. The ionic liquid [C6ImBS]HSO4 could be reused.
Sun, Jiahan,Li, Hansheng,Song, Haoran,Wu, Qin,Zhao, Yun,Jiao, Qingze
p. 87200 - 87205
(2015/11/09)

Tris-imidazolium and benzimidazolium ionic liquids: A new class of biodegradable surfactants
Based on imidazolium and benzimidazolium, two series of novel tris-cationic ionic liquid surfactants containing ester groups were synthesized simply from readily available starting materials in high yields. Biodegradability and surfactants properties of the tris-imidazolium and tris-benzimidazolium ionic liquids were investigated. Some compounds showed assembly behaviour in the pure form (i.e. absence of solvent) and in the presence of polar or nonpolar solvents. These surfactants are effectively reducing the surface tension of water in the range of 28-31 mN m-1. Through using the 'Closed-Bottle Test' OECD 301D, the incorporation of alkyl or phenyl side chains with ester groups in the same molecule significantly improved the biodegradation compared to sodium n-dodecyl sulphate (SDS) as a reference. The aliphatic alkyl side chain, i.e., butyl, hexyl, octyl, decyl and dodecyl, in both imidazolium and benzimidazolium ionic liquids have marked increasing biodegradation and phase behaviour results compared to aromatic side-chains.
Al-Mohammed, Nassir N.,Duali Hussen, Rusnah Syahila,Alias, Yatimah,Abdullah, Zanariah
p. 2869 - 2881
(2015/02/02)

Synthesis of polyoxymethylene dimethyl ethers from methylal and trioxane catalyzed by Br?nsted acid ionic liquids with different alkyl groups
Br?nsted acid ionic liquids with different alkyl group carbon chain lengths and an alkane sulfonic acid group were synthesized through bromoalkane, imidazole and 1,4-butane sultone as raw materials. The structures and properties of the ionic liquids were experimentally characterized. Catalytic reaction of methylal (DMM) with trioxane (TOX) for preparation of polyoxymethylene dimethyl ethers (PODMEn, CH3O(CH2O)nCH3, where n > 1) was investigated in various Br?nsted acid ionic liquids with different carbon chain length of alkyl groups. The carbon chain length of alkyl groups and activity correlation for the ionic liquids was studied. It was found that the structures of ionic liquids were consistent with the designed structure and their purities were high. They possessed high thermal stability and wide liquid range. The hydrophobicity of ionic liquids became stronger with the increase of carbon chain length. With increasing the carbon chain length of ionic liquids, the selectivity of PODME3-8 is increased at first and then decreased. Among all the ionic liquids, [C6ImBS][HSO4] shows the best catalytic performance and the selectivity of PODME3-8 is 57.85%.
Wu, Qin,Li, Weijiao,Wang, Min,Hao, Yu,Chu, Tonghua,Shang, Jiqing,Li, Hansheng,Zhao, Yun,Jiao, Qingze
p. 57968 - 57974
(2015/07/20)

Tetrakis-imidazolium and benzimidazolium ionic liquids: A new class of biodegradable surfactants
Novel series of tetra-cationic ionic liquids containing alkyl or phenyl side chains and ester groups within the same molecule were successfully prepared. Based on imidazolium and benzimidazolium, these ionic liquids were synthesized from readily available starting materials in high yield. Surfactant properties including liquid crystalline behaviour and surface properties as well as their biodegradability were investigated. Tetrakis-imidazolium ionic liquid compounds showed assembly behaviour in the pure form (i.e. spontaneously) and in the presence of polar or nonpolar solvents, while both imidazolium and benzimidazolium ionic liquids effectively reduced the surface tension of water in the range of 29-34 mN m-1. The incorporation of tetra alkyl or phenyl side chains into imidazolium and benzimidazolium ionic liquids with tetra-ester groups, significantly improved the biodegradation. 'Closed-Bottle Test' OECD 301D and sodium n-dodecyl sulphate (SDS) as a reference were used for evaluation. The linear alkyl side chains (i.e. butyl, hexyl, octyl, decyl and dodecyl) in both tetrakis-imidazolium and benzimidazolium ionic liquids promote the increasing in biodegradation and phase behaviour results comparing to aromatic side-chains.
Al-Mohammed, Nassir N.,Duali Hussen, Rusnah Syahila,Ali, Tammar Hussein,Alias, Yatimah,Abdullah, Zanariah
p. 21865 - 21876
(2015/11/27)

A green strategy to enhance a liquid-liquid heterogeneous reaction with a magnetic recyclable Pickering emulsion
This work described a general strategy to enhance a typical organic-aqueous heterogeneous green oxidation reaction by introducing surface tunable magnetic nanoparticles into liquids to form a controllable Pickering emulsion. We synthesized cross-linked polystyrene (PS)-covered Fe3O4 nanoparticles grafted with different N-alkyl imidazoles and systematically discussed the effect of surface properties on the formation of emulsions. By loading such particles, the dichloromethane-water-based 2,2,6,6-tetramethylpiperidine-1-oxyl-mediated Montanari oxidation system was converted from the unstable millimeter-scale dispersion into a stable micrometer-scale emulsion, which significantly reduced the reactant transfer distance and resulted in a significantly high overall reaction rate. This reaction efficiency is elucidated in terms of unique properties inherent in an emulsion, including the self-assembly of Fe3O4/PS and Fe3O4/PS[im-Cn]Cl (n=1, 4, 6, and 10) nanoparticles, well ensuring a large specific surface area of the water-oil interface. Pucker up for a Pickering emulsion: This work describes a general strategy to enhance a typical organic-aqueous heterogeneous green oxidation reaction, in which surface tunable magnetic nanoparticles are introduced into liquids to form a controllable Pickering emulsion. The catalysis results revealed that the stabilized micrometer-scale emulsion for biphasic Montanari oxidation resulted in a significantly higher reaction rate.
Feng, Linbin,Wang, Jianli,Chen, Liang,Lu, Meizhen,Zheng, Zhi,Jing, Ren,Chen, Hualiang,Shen, Xianbo
p. 616 - 624
(2015/03/05)

Antimicrobial activity and SAR study of new gemini imidazolium-based chlorides
A series of 70 new 3,3′(α,ω-dioxaalkyl)bis(1- alkylimidazolium) chlorides were synthesized. They were characterized with respect to surface active properties and antimicrobial activity against the following pathogens: Staphylococcus aureus, Enterococcus faecalis, Acinetobacter baumannii, Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, Pseudomonas aeruginosa, Candida krusei, and Candida albicans. In this article, besides description of the synthesis, we characterize a set of features of these compounds, concerning their structure (described by the length of the dioxaalkan spacer and the length of the alkyl substituent in the aromatic ring) and surface active properties (critical micelle concentration, value of surface tension at critical micelle concentration, value of surface excess, molecular area of a single particle, and free energy of adsorption of molecule). Then, we present a SAR study for Staphylococcus aureus, as one of the most widespread pathogenic strains, conducted with the help of the Dominance-based Rough Set Approach (DRSA), that involves identification of relevant features and relevant combinations of features being in strong relationship with a high antimicrobial activity of the compounds. The SAR study shows, moreover, that the antimicrobial activity is dependent on the type of substituents and their position at the chloride moiety, as well as on the surface active properties of the compounds.
Pa?kowski, ?ukasz,B?aszczyński, Jerzy,Skrzypczak, Andrzej,B?aszczak, Jan,Kozakowska, Karolina,Wróblewska, Joanna,Kozuszko, Sylwia,Gospodarek, Eugenia,Krysiński, Jerzy,S?owiński, Roman
p. 278 - 288
(2014/03/21)

New eco-friendly 1-alkyl-3-(4-phenoxybutyl) imidazolium-based ionic liquids derivatives: A green ultrasound-assisted synthesis, characterization, antibacterial activity and POM analyses
In view of the emerging importance of the ILs as "green" materials with wide applications and our general interests in green processes, a series of a twenty five new 1-alkyl-3-(4-phenoxybutyl) imidazolium-based ionic liquids (ILs) derivatives is synthesized using a facile and green ultrasound-assisted procedure. Their structures were characterized by FT-IR, 1H-NMR, 13C-NMR, 11B, 19F, 31P, and mass spectrometry. Antimicrobial screens of some selected ILs were conducted against a panel of Gram-positive and Gram-negative bacteria. The antimicrobial activity of each compound was measured by determination of the minimal inhibitory concentration (MIC) yielding very interesting and promising results. Their antibacterial activities are reported, and, on the basis of the experimental and virtual POM screening data available, attempt is also made to elucidate the structure activity relationship.
Messali, Mouslim,Aouad, Mohamed R.,El-Sayed, Wael S.,Ali, Adeeb Al-Sheikh,Hadda, Taibi Ben,Hammouti, Belkheir
p. 11741 - 11759
(2014/11/08)

Haloaurate and halopalladate imidazolium salts: Structures, properties, and use as precursors for catalytic metal nanoparticles
The synthesis and characterisation of a series of new gold- and palladium-containing symmetrical imidazolium salts are described which display significant cation-dependent effects determined by the structure of the alkyl chains of the imidazolium motifs. Whereas direct reduction of the Pd salts can produce stable nanoparticles (NPs) coated by imidazolium salts, the addition of strong base to the Pd or Au salts before reduction gives stable NPs, potentially pacified by N-heterocyclic carbene units. The possibility of NP surface protection by metal-carbon bonds in these systems is investigated by spectroscopic, synthetic, and catalytic investigations, providing support for the hypothesis. Significantly, the catalytic activity of the NPs is not inhibited by the continued presence of the ligands. The Royal Society of Chemistry 2013.
Serpell, Christopher J.,Cookson, James,Thompson, Amber L.,Brown, Christopher M.,Beer, Paul D.
p. 1385 - 1393
(2013/03/13)

Chemo-immunotherapeutic antimalarials targeting isoprenoid biosynthesis
We synthesized 30 lipophilic bisphosphonates and tested them in malaria parasite killing (targeting parasite geranylgeranyl diphosphate synthase, GGPPS) and human γδ T cell activation (targeting human farnesyl diphosphate synthase, FPPS). Similar patterns of activity were seen in inhibiting human FPPS and Plasmodium GGPPS, with short to medium chain-length species having most activity. In cells, shorter chain-length species had low activity, due to poor membrane permeability, and longer chain length species were poor enzyme inhibitors. Optimal activity was thus seen with ～C 10 side-chains, which have the best combination of enzyme inhibition and cell penetration. We also solved the crystal structure of one potent inhibitor, bound to FPPS. The results are of interest since they suggest the possibility of a combined chemo/immuno-therapeutic approach to antimalarial development in which both direct parasite killing and γδ T cell activation can be achieved with a single compound.
Zhang, Yonghui,Zhu, Wei,Liu, Yi-Liang,Wang, Hong,Wang, Ke,Li, Kai,No, Joo Hwan,Ayong, Lawrence,Gulati, Anmol,Pang, Ran,Freitas-Junior, Lucio,Morita, Craig T.,Oldfield, Eric
supporting information
p. 423 - 427
(2013/06/05)

Symmetrical 1, 3-Dialkylimidazolium Based Ionic Liquid Crystals
The synthesis and characterization for a series of symmetrical 1, 3-dialkylimidazolium salts with different chain lengths and counter anions together with their 1-alkylimidazole precursors are described. Liquid crystal (LC) properties of these salts are studied. Images under polarizing optical microscopy show focal conic texture together with homeotropic domains. A smectic A mesophase, typical for rod-like imida-zolium salts, is assigned. Studies from powder X-ray diffraction suggest a lamellar structure with non-interdigitated monolayer arrangement for the LC salts in the mesophase. In addition, a short note on the structure and property relationship for rod-like, discor fan-like, and dendritic shaped imidazolium ionic liquid crystals (ImILCs) forming smectic, columnar, and cubic phase is briefly summarized. Acomparison of minimum alkyl chain length needed for 1-alkyl-3-methyl and symmetrical 1, 3-dialkyl ImILCs to exhibit LC behavior is addressed.
Rohini, Rondla,Lee, Ching-Kuan,Lu, Jung-Tang,Lin, Ivan J.B.
p. 745 - 754
(2013/11/06)

β-Carotene: A green, inexpensive, and convenient solvatochromic probe for the determination of solvent polarizability
Solvent polarizability has been previously determined by using the solvatochromic probe 3,20-di-tert-butyl-2,2,21,21-tetramethyl-3,5,7,9,11,13,15, 17,19-docosanonaene whose synthesis involves 15 steps. We show here that the natural dye β-carotene, 1,1′-(3,7,12,16-tetramethyl-1,3,5,7,9,11,13, 15,17-octadecanonaene-1,18-diyl)bis[2,6,6-trimethylcyclohexene], can be conveniently employed for the accurate determination of the same solvent property. This conclusion is based on both theoretical calculations and experimental data. The former includes free energies of solvation, and the wavenumber of the longest wavelength (i.e., the solvatochromic) transition. Both quantities for β-carotene correlate linearly with the corresponding values of the docosanonaene, with slopes and correlation coefficients of practically unity. The plot of experimentally calculated solvent polarizability of β-carotene versus that of the docosanonaene was found to be linear for 68 solvents. Previously unknown solvent polarizability values are reported for eight ROCH2CH2OH (R = C1 to C10) and four 1-allyl-3-R-imidazolium chloride ionic liquids (R = C6 to C10). The dependence of solvent polarizability on the number of carbon atoms in the hydrocarbon chains of several classes of solvents is calculated, it shows the importance of van der Waals interactions in ionic liquids.
Loffredo, Carina,Pires, Paulo Augusto R.,Imran, Muhammad,El Seoud, Omar A.
p. 16 - 24,9
(2020/07/31)

Anisotropic ionic conductivity in fluorinated ionic liquid crystals suitable for optoelectronic applications
In this work, we report a library of thirteen fluorinated ionic liquids consisting of iodide salts of 1-alkyl-3-polyfluoroalkyl-imidazolium cations. By changing the length of the alkyl and polyfluoroalkyl pendants, we discovered that particular combinations of these result in compounds showing a mesophase. The nature and the molecular arrangement of the mesophase are characterised by polarised optical microscopy and powder X-ray diffraction analysis, among others. We demonstrate that, after the addition of I2 to generate the I-/I3- redox couple, anisotropic ionic conductivity takes place along preferential pathways in the lamellar structure of the mesophase. Notably, the addition of I2 does not suppress the mesophase temperature range, contrary to previously reported systems. Furthermore, the tendency of these materials to supercool allows the molecular arrangement in the mesophase to be retained in a solid film at ambient temperatures. Finally, we demonstrate their applicability as a quasi-solid electrolyte by preparing dye-sensitised solar cells with power conversion efficiencies comparable to the previous reports.
Abate, Antonio,Petrozza, Annamaria,Cavallo, Gabriella,Lanzani, Guglielmo,Matteucci, Francesco,Bruce, Duncan W.,Houbenov, Nikolay,Metrangolo, Pierangelo,Resnati, Giuseppe
p. 6572 - 6578
(2013/07/26)

Synthesis, limitations, and thermal properties of energetically- substituted, protonated imidazolium picrate and nitrate salts and further comparison with their methylated analogs
The possibility of forming simple energetic ionic liquids via the straightforward protonation of heterocyclic amines with nitric or picric acid was explored with 1-alkylimidazoles, 1-alkyl-2-methylimidazoles, and nitro, dinitro, and dicyano-substituted derivatives. The melting points of most of the prepared salts were lower than expected and of the 30 compounds prepared, more than half were found to melt below 100 °C. Limitations in the approach were found as a result of the use of energetic electron withdrawing substituents, such as nitro or cyano, which results in a reduction in nucleophilicity of the heterocycle and an inability to form salts with the acids studied. Interesting thermal behavior was observed with several of the new salts including supercooling and crystallization on heating. Comparison of the simple protonated imidazolium nitrate and picrate salts with their methylated analogs indicated that the protonated ionic liquids do not differ substantially in their melting points from the methylated analogs. However, the thermal stabilities of protonated imidazolium salts are much lower than their alkylated derivatives. Nitrate salts with alkylated cations tend to be more thermally stable than the corresponding picrate salts, but with protonated cations, the picrate salts tend to be approximately 70-80 °C more stable than the nitrate salts. Moreover, accelerating rate calorimetry (ARC) revealed that alkylated salts decompose much less exothermically (in some cases endothermically) than the protonated analogs, and that among all the analyzed salts, the most energetic materials found were protonated 1-methylimidazolium nitrate and 1,2-dimethylimidazolium picrate. The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2012.
Smiglak, Marcin,Hines, C. Corey,Reichert, W. Matthew,Vincek, Adam S.,Katritzky, Alan R.,Thrasher, Joseph S.,Sun, Luyi,McCrary, Parker D.,Beasley, Preston A.,Kelley, Steven P.,Rogers, Robin D.
experimental part
p. 702 - 722
(2012/05/04)

Activated carbon as a catalyst for the synthesis of N-alkylimidazoles and imidazolium ionic liquids
An activated carbon Norit RX3 has been treated with acids (sulphuric, nitric and sulphonitric mixture). The modified activated carbons have been characterized by elemental analysis, point of zero charge, N2 adsorption, XPS and FTIR. The solids obtained have been used as acidic heterogeneous catalyst in the reaction between imidazole and haloalkanes. The reaction with 1-bromobutane yields an ionic liquid, N,N-di-n-butyl-imidazolium bromide (1). Reaction with 2-bromobutane and 1-chlorohexane yields the corresponding N-alkyl-imidazoles (2) and (3). Sulphuric acid treated carbon is the most active catalyst.
Durán-Valle,Madrigal-Martínez,Martínez-Gallego,Fonseca,Matos,Botelho Do Rego
experimental part
p. 108 - 114
(2012/07/16)

1,2-Bis[N-(N′-alkylimidazolium)]ethane salts: A new class of organic ionic plastic crystals
A new class of organic ionic plastic crystals was discovered. A series of alkylene 1,2-bis[N-(N′-alkylimidazolium)] salts with Br- and PF6- anions was prepared and most of the ethylene (C 2) linked compounds undergo multiple solid-solid phase transitions as determined by differential scanning calorimetry (DSC). The salts with longer spacers (C3 or C4) between the imidazolium units do not display any solid-solid transitions. The PF6- salts with terminal C10 and C12n-alkyl moieties are "classical" organic ionic plastic crystals by Timmermans' definition; they have low ΔSf (11 J K-1 mol-1 for C10 and 12 J K-1 mol-1 for C12). Additionally, the C2 linked bis-imidazolium salts with n-butyl, n-hexyl, n-heptyl and n-octyl termini all undergo two, three or four solid state transitions and exhibit ΔSf values in the range of 36-49 J K-1 mol-1, which are similar to those of other known ionic plastic crystalline materials. These materials were additionally characterized via ionic conductivity and solid state NMR. These ionic plastic crystals are presumably single-ion conductors, but the ionic conductivities appear to be too low for practical applications. The activation energy for conduction decreases as these compounds are heated through each solid-solid transition. The lack of any change in solid state 2H NMR spectra with temperature indicates that there is no change in phenyl ring flipping, suggesting no change in the imidazolium local environment. A resolution of this apparent dichotomy is perhaps that the counterions reside with the ethylene spacers between imidazolium moieties.
Lee, Minjae,Choi, U Hyeok,Wi, Sungsool,Slebodnick, Carla,Colby, Ralph H.,Gibson, Harry W.
supporting information; experimental part
p. 12280 - 12287
(2011/12/21)

Halogen bond anion templated assembly of an imidazolium pseudorotaxane
Halogen bonding has been exploited in the assembly of an interpenetrated molecular system. The strength of chloride-anion-templated pseudorotaxane formation with a 2-bromo-functionalized imidazolium threading component and an isophthalamide macrocycle (see picture) is significantly enhanced compared to hydrogen-bonded pseudorotaxane analogues. (Figure Presented).
Serpell, Christopher J.,Kilah, Nathan L.,Costa, Paulo J.,Felix, Vitor,Beer, Paul D.
supporting information; experimental part
p. 5322 - 5326
(2010/10/19)

Etherification of glycerol by isobutylene: Tuning the product composition
Etherification of glycerol by isobutylene was conducted in a batch mode using acidic and partially neutralized Amberlyst-15 ionic resin, p-toluenesulfonic acid, silicotungstic acid, cesium salt of silicotungstic acid, and ionic liquid containing sulfonic acid groups. All the catalysts are comparable in terms of the initial rate of glycerol conversion into mono-ether (except cesium salt of heteropolyacid), but differ substantially with respect to the yields of higher ethers of glycerol. Ionic liquid and heteropolyacid are immiscible/insoluble in higher ethers of glycerol. As a result they have unique capability of suppressing the formation of tri-ether during the initial stage of glycerol conversion. Acidic Amberlyst-15 in the form of fine powder has the highest activity per unit weight for glycerol etherification and relatively high activity in isobutene oligomerization. Partial exchange of acidic protons with cations Na+, Ag+, Mg2+, and Al3+ decreases the rates of all the processes, but isobutylene oligomerization is suppressed more efficiently. Ag+- and Al3+-modified Amberlyst demonstrates higher yields of tri-ether and has specific pattern of interaction with gaseous isobutene distinctive to other metal-substituted Amberlysts.
Lee, Hee Jong,Seung, Doyoung,Jung, Kwang S.,Kim, Hwayong,Filimonov, Igor N.
body text
p. 235 - 244
(2012/01/02)

Peroxopolyoxometalate-based room temperature ionic liquid as a self-separation catalyst for epoxidation of olefins
A new peroxopolyoxometalate-based room temperature ionic liquid (POM-RTIL) has been synthesized and used as catalyst for efficient epoxidation of various olefins. The RTIL catalyst was found to be well dissolved in the solvent (ethyl acetate) during the reaction, while it can self-separate from the reaction media at room temperature after the reaction completed, which made the recovery and reuse of the IL catalyst convenient. The POM-RTIL catalyst can be recycled for five times without significant loss of activity.
Li, Huan,Hou, Zhenshan,Qiao, Yunxiang,Feng, Bo,Hu, Yu,Wang, Xiangrui,Zhao, Xiuge
scheme or table
p. 470 - 475
(2010/11/21)

Heteroaryl Salts and Methods For Producing and Using the Same
The invention provides heteroaryl salts and methods for producing the same. In particular, the invention provides heteroaryl salts of the formula: and methods for producing the same, where M, a, X1, X2, X3, and X4 are those defined herein.
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Page/Page column 6

(2009/07/17)

Polyoxometalate-based protic alkylimidazolium salts as reaction-induced phase-separation catalysts for olefin epoxidation
Two protic alkylimidazolium polyoxometalates, together with two corresponding aprotic N-methyl-alkylimidazolium polyoxometalates were synthesized and characterized by the methods of NMR, IR and TGA etc. Then, these salts were employed as catalysts for the epoxidation of cyclooctene in different media. The novel protic N-dodecylimidazolium peroxotungstate [HDIm]2[{WO(O2)2}2(μ-O)] was found to be a room temperature liquid molten salt (ionic liquid) and the most effective catalyst for the epoxidation of cyclooctene among these salts. The ionic liquid catalyst [HDIm]2[{WO(O2)2} 2(μ-O)] can also be extended to the epoxidation of some other substrates. On the basis of this experimental observation, an efficient reaction-induced phase-separation catalyst system has been developed in this work. The reaction system can switch from tri-phase to emulsion and then to biphase and finally to all the catalyst self-precipitating at the end of the reaction, which made the recovery and reuse of the present catalyst very convenient.
Qiao, Yunxiang,Hou, Zhenshan,Li, Huan,Hu, Yu,Feng, Bo,Wang, Xiangrui,Hua, Li,Huang, Qingfa
experimental part
p. 1955 - 1960
(2010/06/15)

Artificial enzymes with thiazolium and imidazolium coenzyme mimics
Hydrophobic thiazolium and imidazolium coenzyme mimics in the presence of modified-polyethylenimine enzyme mimics catalyze the benzoin condensation 2300-3300 times faster than the coenzyme mimics alone. Polycationic enzyme mimics provide not only a hydrophobic binding domain for coenzyme and substrate, but also electrostatic stabilization of anionic species that arise along the reaction pathway of the benzoin condensation. Copyright
Zhao, Huanyu,Foss Jr., Frank W.,Breslow, Ronald
supporting information; experimental part
p. 12590 - 12591
(2009/04/10)

Synthesis and properties of chiral imidazolium ionic liquids with a (1R,2S,5R)-(-)-menthoxymethyl substituent
A series of 1-[(1R,2S,5R)-(-)-menthoxymethyl]-3-alkylimidazolium salts have been synthesized, producing both hydrophilic and hydrophobic chiral imidazolium ionic liquids. Their physicochemical properties, single-crystal X-ray structures, antimicrobial activities, and antielectrostatic effects were determined and these compounds have proven to represent not only potential new solvents in asymmetric synthesis, but also effective, disinfectants with antielectrostatic activity. Given the number and diversities of the possible conformations and interionic interactions, coupled with the chiral nature of the cations, it should come as no surprise that these salts exhibit ionic liquid behavior and are so difficult to crystallize. The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.
Pernak, Juliusz,Feder-Kubis, Joanna,Cieniecka-Ros?onkiewicz, Anna,Fischmeister, Cedric,Griffin, Scott T.,Rogers, Robin D.
p. 879 - 892
(2008/02/12)

Self-assembled N-alkylimidazolium perfluorooctanesulfonates
Thermostability of a smectic A phase composed of N-alkyl-imidazolium heptadecafluorooctanesulfonate was improved by the formation of nonpolar layer composed of mixed perfluoroalkyl and aliphatic chains. Copyright
Mukai, Tomohiro,Yoshio, Masafumi,Kato, Takashi,Ohno, Hiroyuki
p. 442 - 443
(2007/10/03)

Synthesis of novel chiral ionic liquids and their phase behavior in mixtures with smectic and nematic liquid crystals
Alkylation of 1-alkyl-1H-imidazoles 2a-f with citronellyl bromide 1b opens access to chiral 1H-imidazolium bromides 3a-f (Scheme 1). A similar strategy yielded the chiral pyridinium ionic liquid 6 (Scheme 2). Dialkylation of 1H-imidazole (7) gave the C2-symmetric 1,3-dicitronellyl-1H- imidazolium bromide (8) (Scheme 3). Differential scanning calorimetry and optical polarizing microscopy revealed smectic mesophases for 1-citronellyl-3-tetradecy-1H-limidazolium bromide (3e) and 1- citronellylpyridinium bromide (6) (Table). In binary mixtures with smectic and nematic liquid crystals 9 and 10, 1-citronellyl-3-methyl-1H-imidazolium bromide (3a) behaved differently. Increasing quantities of 3a cause a decrease of the smectic-phase width for the mixture 3a/9 (Fig. 3), whereas the phase width of the nematic phase for 3a/10 remained nearly constant (Fig. 4).
Tosoni, Martin,Laschat, Sabine,Baro, Angelika
p. 2742 - 2749
(2007/10/03)

Synthesis of N-alkylated derivatives of imidazole as antibacterial agents
N-Alkylation of imidazole, 2-methylimidazole and 2-methyl-4-nitroimidazole have been carried out to achieve effective antibacterial agents. The products were then investigated for antibacterial activity against Escherichia coil, Staphylococcus aureus and Pseudomonas aeruginosa. Antibacterial effects of 1-alkylimidazole derivatives increase as the number of carbons in alkyl chain increases up to nine carbons. Also substitution of 2-methyl and 2-methyl-4-nitro groups on imidazole ring increases the antibacterial activity.
Khabnadideh,Rezaei,Khalafi-Nezhad,Bahrinajafi,Mohamadi,Farrokhroz
p. 2863 - 2865
(2007/10/03)

Synthese et proprietes antibacteriennes et antifongiques d'une serie de 1-alkylimidazoles
A homologous series of 1-alkylimidazoles (pentyl to octadecyl) has been obtained with a good yield (75-95percent) by the phase transfer catalyzed reaction of imidazole with the appropriate alkyl halides.The antifungal and antibacterial activities of these compounds were tested.A poor activity was observed towards the Gram-negative (Gram-) microorganisms, whereas the aerobic and anaerobic Gram-positive (Gram+) microorganisms and some yeasts (Pityrosporum ovale) were inhibited.We found that the inhibitory potency of such compounds increased with increasing chain length,passing through a maximum with chain length C10-C13 and decreased for the higher homologs.An explanation is suggested in relation to the ability of these compounds to bind with the active sites of the microorganisms and to adopt a conformation able to promote the migration through the biological membranes.
Savignac, A. de,Roques, C.,Hinedi, M.,Michel, G.,Lattes, A.
p. 449 - 454
(2007/10/02)

3-Imidazolium cephalosporin derivatives
A cephalosporin compound substituted by imidazolium ring in 3-position of cephem having the following formula (I), and pharmaceutically acceptable salt thereof, STR1 wherein R1 is an organic residue known in β-lactam antibiotics, R2 is hydrogen atom or methoxy, n is 0 or 1, A is a nitrogen-containing group constituting imidazolium ring, is useful as an agent for preventing and treating bacterial infections.
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(2008/06/13)

Highly Efficient NaOCl Olefin Epoxidations Catalyzed by Imidazole or Pyridine "Tailed" Manganese Porphyrins under Two-Phase Conditions. Influence of pH and of the Anchored Axial Ligand
Mn(III) tetraarylporphyrins 2 and 3, bearing a pyridine or an N-alkyl-substituted imidazole function anchored by an aliphatic chain, are extremely efficient catalysts for olefin epoxidations carried out with NaOCl under aqueous-organic two-phase conditions.Reaction rates are strongly increased by lowering the pH of the aqueous phase, and at pH 9.5 catalyst turnovers are in the range of 0.8-3.3 per s at 0 deg C.At the lower pH values rates are only slightly affected by the presence of a phase-transfer catalyst, whereas the latter becomes important at the pH of commercial bleach (12.5-13.0).A similar behavior has been found for epoxidations catalyzed by Mn(III) tetraphenylporphyrin 1, carried out in the presence of a molar excess of 3-pycoline or N-hexylimidazole.The latter is a particularly effcient axial ligand.
Montanari, Fernando,Penso, Michele,Quici, Silvio,Vigano, Patrizia
p. 4888 - 4893
(2007/10/02)

An improved and convenient procedure for the synthesis of 1-substituted imidazoles
1-Protected imidazoles, such as 1-acetyl- and 1-benzoylimidazoles, react with various halides, such as benzyl, allyl, α-keto, and alkyl halides, to give 1-protected-3-substituted imidazolium salts in high yields. The resultant imidazolium salts are easily deprotected by treatment with water or alcohols to give the corresponding 1-substituted imidazoles in excellent yields. In this reaction the yields of 1-substituted imidazoles vary with the kinds of halides used and/or with the protecting groups, and the yields increase in the following order: benzyl halides≥allyl halides~α-keto halides>alkyl halides, and acetyl≥benzoyl>ethoxycarbonyl>diethoxymethyl>trimethylsilyl>tosyl.
Kamijo,Yamamoto,Harada,Iizuka
p. 1213 - 1221
(2007/10/02)

Pharmaceutically active imidazole derivatives
The invention relates to a class of imidazoles substituted by cycloalkyl or cycloalkenyl which have pharmacological properties making them useful in medicine, in particular in the prophylaxis and treatment of thrombo-embolic disorders.
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(2008/06/13)