- Photoresponsive Self-Assembly of Surface Active Ionic Liquid
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A novel photoresponsive surface active ionic liquid (SAIL) 1-(4-methyl azobenzene)-3-tetradecylimidazolium bromide ([C14mimAzo]Br) with azobenzene located in the headgroup was designed. Reversible vesicle formation and rupture can be finely controlled by photostimuli without any additives in the aqueous solution of the single-tailed ionic liquid. The photoisomerization of the azobenzene derivative was investigated by 1H NMR and UV-vis spectroscopy. Density functional theory (DFT) calculations further demonstrate that trans-[C14mimAzo]Br has less negative interaction energy, which is beneficial to aggregate formation in water. The incorporation of trans-azobenzene group increases the hydrophobicity of the headgroup and reduces the electrostatic repulsion by delocalization of charge, which are beneficial to the formation of vesicles. However, the bend of cis-azobenzene makes the cis-isomers have no ability to accumulate tightly, which induces the rupture of vesicles. Our work paves a convenient way to achieve controlled topologies and self-assembly of single SAIL.
- Wu, Aoli,Lu, Fei,Sun, Panpan,Gao, Xinpei,Shi, Lijuan,Zheng, Liqiang
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- A Remarkable Fluorescence Quenching Based Amplification in ATP Detection through Signal Transduction in Self-Assembled Multivalent Aggregates
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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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supporting information
p. 13595 - 13600
(2020/10/06)
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- Aggregation behavior of zwitterionic surface active ionic liquids with different counterions, cations, and alkyl chains
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A group of zwitterionic surface active ionic liquids (SAILs) with different counterions, cations and alkyl chains, 3-(1-alkyl-3-imidazolio)propanesulfonate β-naphthalene sulfonate, (CnIPS-Nsa, n = 12, 14), 3-(1-dodecyl-3-imidazolio)propanesulfonate benzenesulfonate (C12IPS-Bsa), and dodecyl-N,N-dimethylammonio-3-propane sulfonate β-naphthalene sulfonate (SB-12-Nsa), were synthesized. Their aggregation behaviors in aqueous solutions were systematically investigated by surface tension, dynamic light scattering (DLS) and 1H NMR spectroscopy. Surface tension and DLS results illustrated that the surface properties, micelle size, and micellization behavior of zwitterionic SAILs in aqueous solutions are significantly affected by the anion type, anionic structure and the hydrophobicity of the alkyl chain. The SAILs with more hydrophobic anions and long alkyl chains are expected to favor the micellization. The steric hindrance and hydrophobicity of the cations, as well as the binding strength of the cations with the anions, also play important roles in the aggregation of zwitterionic SAILs. Additionally, the micelle formation mechanism was acquired by detailed analysis of the 1H NMR spectra. The existence of π-π stacking between imidazolium and counterions was proved. The enhanced π-π stacking and hydrophobic effect of Nsa- can promote the aggregation of zwitterionic SAILs. Density functional theory (DFT) calculations illustrated that the negative interaction energy of the complexes were C12IPS-Bsa/H2O > SB-12-Nsa/H2O > C12IPS-Nsa/H2O > C14IPS-Nsa/H2O. It is more difficult to form micelles in complexes with more negative interaction energy. The counterion electronegativity of Nsa- is smaller than that of Bsa-, which favors the formation of micelles.
- Sun, Panpan,Shi, Lijuan,Lu, Fei,Zheng, Liqiang
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p. 27370 - 27377
(2016/03/30)
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- 1,1 the [...] -di-alkyl -3,3 the [...] -(2-phosphate ester -1,3-propyl) imidazole in the process for the preparation of salt compound
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The invention relates to a 1,1'-dialkyl-3,3'-(2-phosphate-1,3-propylidene)imidazolium compound and a preparation method thereof. The structural formula of the 1,1'-dialkyl-3,3'-(2-phosphate-1,3-propylidene)imidazolium compound is shown in the specification, wherein n is 6, 8, 10, 12 and 14, and the alkyl imidazole can be replaced with alkyl benzimidazole. The 1,1'-dialkyl-3,3'-(2-phosphate-1,3-propylidene)imidazolium is a amphoteric dimeric surfactant, and a concrete synthesis method comprises the following steps: synthesizing 1, 3-dichloro-2-propanol, synthesizing N-alkyl imidazole, synthesizing 1,1'-dialkyl-3,3'-(2-hydroxyl-1,3-propylidene)imidazole hydrochloride, and synthesizing 1,1'-dialkyl-3,3'-(2-phosphate-1,3-propylidene)imidazolium. The 1,1'-dialkyl-3,3'-(2-phosphate-1,3-propylidene)imidazolium compound and the preparation method are easily available in raw materials, the reaction technology conditions are easy to control, operation is simple, the product is easy to purify, and yield is high. The compound has low critical micelle concentration, and can be used as a wetting agent, an emulsifier, a foaming agent and a foam stabilizer. A molecular structure has macrocyclic cefpimizole group and phosphate ester, and thus the compound has good thermal stability, solubility, salinity resistance, temperature resistance and acid and base resistance.
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Paragraph 0069; 0070
(2016/12/07)
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- A Comprehensive Study on the Synthesis and Micellization of Disymmetric Gemini Imidazolium Surfactants
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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
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p. 681 - 691
(2016/07/06)
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- Synthesizing method of imidazole type Gemini surfactant
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The invention discloses a synthesizing method of imidazole type Gemini surfactant. The synthesizing method is characterized in that N-alkyl imidazole is synthesized by using imidazole and alkyl bromide, reaction temperature is 25 DEG C, reaction time is 8 hours, and the yield is about 70%; bromoacetic acid 1, 4-butanediyl ester is synthesized by using bromoacetic acid and dihydric alcohol, reaction temperature is 125 DEG C, and reaction time is 24 hours; the final product is synthesized by using the N-alkyl imidazole and the bromoacetic acid 1, 4-butanediyl ester, reaction temperature is 85 DEG C, reaction time is 36 hours, and yield is about 85%. The synthesizing path is shown as follows, wherein n=2, 4, 6.
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Paragraph 0010
(2016/10/09)
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- Synthesis of polyoxymethylene dimethyl ethers from methylal and trioxane catalyzed by Br?nsted acid ionic liquids with different alkyl groups
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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
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p. 57968 - 57974
(2015/07/20)
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- Temperature-responsive proton-conductive liquid crystals formed by the self-assembly of zwitterionic ionic liquids
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In the present study, we synthesized a series of ionic liquids by mixing amphiphilic imidazolium-type zwitterions with sulfonic acids containing different substituent groups. Nanostructured proton conductors having hexagonal and cubic structures were constructed by the self-assembly of these zwitterionic ionic liquids. These nanostructured proton conductors exhibited an assembled-structure dependent proton conduction behavior. The introduction of highly ordered liquid crystal structures efficiently improved ionic conductivity, suggesting the induction of proton conduction through a hopping mechanism. Temperature-responsive ionic conductivity behavior based on phase transition within the self-assembled liquid crystal structures was also observed.
- Gao, Xinpei,Lu, Fei,Dong, Bin,Zhou, Tao,Liu, Yizhi,Zheng, Liqiang
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p. 63732 - 63737
(2015/08/11)
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- Imidazolium-based zwitterionic surfactants: Characterization of normal and reverse micelles and stabilization of nanoparticles
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This paper presents the physicochemical properties of micellar aggregates formed from a series of zwitterionic surfactants of the type 3-(1-alkyl-3-imidazolio)propane-sulfonate (ImS3-n), with n = 10, 12, 14, and 16. The ImS3-n dipolar ionic surfactants represent a versatile class of dipolar ionic compounds, which form normal and reverse micelles. Furthermore, they are able to stabilize nanoparticles in water and in organic media. Aqueous solubility is too low at room temperature to allow characterization of micellar aggregates but increases with addition of salts, allowing determination of aggregation number and cmc. As expected, these parameters depend on the length of the alkyl chain, and cmc values follow Klevens equation. In the presence of NaClO4, all ImS3-n micelles become anionoid by incorporating ClO4- on the micellar interface. A special feature of these surfactants is the ability to form reverse micelles and solubilize copious amounts of saline solutions in chloroform. 1H NMR and infrared spectroscopic evidence showed that the maximum water to surfactant molar ratio w0 achievable depends on the concentration and type of salt dissolved. Reverse micelles of the ImS3-n surfactants can be used to stabilize metallic nanoparticles, whose size may be tuned by the amount of water dissolved.
- Souza, Franciane D.,Souza, Bruno S.,Tondo, Daniel W.,Leopoldino, Elder C.,Fiedler, Haidi D.,Nome, Faruk
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p. 3587 - 3595
(2015/04/14)
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- Synthesis of methylal from methanol and formaldehyde catalyzed by Br?nsted acid ionic liquids with different alkyl groups
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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
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p. 87200 - 87205
(2015/11/09)
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- Antimicrobial activity and SAR study of new gemini imidazolium-based chlorides
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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
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p. 278 - 288
(2014/03/21)
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- CO2/N2 triggered Switchable surfactants with imidazole group
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In order to overcome the hydrolysis of 2-alkyl-1-hydroxyethyl imidazoline and its unsatisfactory emulsification-demulsification switchability to water-alkane, the long-chain N-alkylimidazole compounds were synthesized by n-octyl bromide, n-decyl bromide, n-dodecyl bromide, n-tetradecyl bromide and n-hexadecyl bromide with imidazole, respectively and characterized by MS, 1H NMR and FTIR. The long-chain N-alkylimidazole compounds can be reversibly transformed into charged surfactants by exposure to CO2. Surface tension values indicated that N-alkylimidazolium bicarbonates had excellent surface activity compared with corresponding conventional surfactants with a lower γ CMC. The surface behaviors of the five surfactants can be illustrated by A min. Five conductivity cycles by bubbling CO2 and N2 alternately indicated that these surfactants could be switched by CO2 reversibly and repeatedly. Emulsions were repeatedly stabilized for five cycles by N-alkylimidazolium bicarbonate and broken by bubbling N2 through the solutions to reverses the reaction, releasing CO2.
- Chai, Mingfeng,Zheng, Zhibo,Bao, Lei,Qiao, Weihong
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p. 383 - 390
(2014/05/20)
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- Chemo-immunotherapeutic antimalarials targeting isoprenoid biosynthesis
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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
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supporting information
p. 423 - 427
(2013/06/05)
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- Symmetrical 1, 3-Dialkylimidazolium Based Ionic Liquid Crystals
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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.
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p. 745 - 754
(2013/11/06)
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- Synthesis of a new zwitterionic surfactant containing an imidazolium ring. Evaluating the chameleon-like behavior of zwitterionic micelles
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Synthesis of a new zwitterionic surfactant containing the imidazolium ring 3-(1-tetradecyl-3-imidazolio)propanesulfonate (ImS3-14) is described. The solubility of ImS3-14 is very low but increases on addition of a salt which helps to stabilize the micellized surfactant. Fluorescence quenching and electrophoretic evidence for ImS3-14 shows that the micellar aggregation number is only slightly sensitive to added salts, as is the critical micelle concentration, but NaClO4 markedly increases zeta potentials of ImS3-14 in a similar way as in N-tetradecyl-N,N-dimethylammonio-1- propanesulfonate (SB3-14) micelles. The rate of specific hydrogen ion catalyzed hydrolysis of 2-(p-heptoxyphenyl)-1,3-dioxolane and equilibrium protonation of 1-hydroxy-2-naphthoate ion in zwitterionic micelles of ImS3-14 and SB3-14 are increased markedly by NaClO4 which induces anionoid character and uptake of H3O+, but NaCl is much less effective in this respect. Comparison of ImS3-14 with SB3-14 is based on experimental evidence, and computational calculations indicate similarities and differences in structures of both compounds.
- Tondo, Daniel W.,Leopoldino, Elder C.,Souza, Bruno S.,Micke, Gustavo A.,Costa, Ana C. O.,Fiedler, Haidi D.,Bunton, Clifford A.,Nome, Faruk
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experimental part
p. 15754 - 15760
(2011/10/19)
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- Morita-baylis-hillman reaction on water without organic solvent, assisted by a 'catalytic' amount of amphiphilic imidazole derivatives
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A Morita-Baylis-Hillman (MBH) reaction using water as a solvent without any organic solvent can be performed by using an amphiphilic N-alkylimidazole. This reaction is accelerated by the addition of water and is the first example of a 'catalytic' MBH reaction without organic solvent in the presence of water.
- Asano, Keisuke,Matsubara, Seijiro
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experimental part
p. 3219 - 3226
(2010/02/28)
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- Synthesis of novel chiral ionic liquids and their phase behavior in mixtures with smectic and nematic liquid crystals
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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
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p. 2742 - 2749
(2007/10/03)
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- Synthesis of N-alkylated derivatives of imidazole as antibacterial agents
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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
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p. 2863 - 2865
(2007/10/03)
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- Formation and Deposition of Langmuir Films of Binary and Ternary Systems
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Long chained alkylheteroaromatic compounds such as: 3-n-alkylpyrroles, 1-n-alkylimidazoles, phenylhydrazones of 3-n-alkanoylpyrrole and poly(3-n-alkylthiophenes) with 12 to 18 carbon atoms in the alkyl chain were synthesized as materials for formation of Langmuir and Langmuir-Blodgett films by both individual species as well as by mixtures. It was shown that a positive synergy exists in binary and ternary mixtures containing poly(3-n-alkylthiophenes) resulting in formation of good-quality film on aqueous surface. Several compounds were found to be good films builders for poly(3-n-alkylthiophenes) facilitating the film transfer onto solid surfaces. Among the species examined the best builder was 3-n-octadecylpyrrole. Key words: Langmuir-Blodgett films, poly(3-n-alkylthiophenes), alkylpyrroles, alkylimidazoles, synthesis
- Kucharski, S.,Janik, R.,Bryjak, M.,Bienkowski, M.,Chyla, A.,Sworakowski, J.
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p. 447 - 460
(2007/10/02)
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- Synthese et proprietes antibacteriennes et antifongiques d'une serie de 1-alkylimidazoles
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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.
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p. 449 - 454
(2007/10/02)
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