- Preparation of protic ionic liquids with minimal water content and 15N NMR study of proton transfer
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Low-molecular-weight Bronsted acids and amine bases were used to reproducibly prepare very dry, high-purity room-temperature protic ionic liquids (PILs). A series of eight amine bases and six Bronsted acids were combined to produce 48 mixtures, of which 18 were liquid at room temperature. The phase transitions and thermal decomposition temperatures were determined for each mixture; whereas viscosity, density and conductivity were determined for the room-temperature liquids. By utilising 15N NMR it was possible to distinguish between neutral and ionised amine bases (ammonia vs. ammonium-type ion), which indicated that the protic ionic liquids were completely ionised when made as a stoichiometric mixture. However, a Walden plot comparison of fluidity and molar conductivity indicated the majority of PILs had much lower conductivity than predicted by viscosity unless the base contained excess proton-donating groups. This disparity is indicative of protic ionic molecules forming neutral aggregates or non-Newtonian fluid hydrogen-bonded networks with a secondary Grotthuss proton-hopping mechanism arising from polyprotic bases. the Owner Societies 2010.
- Burrell, Geoffrey L.,Burgar, Iko M.,Separovic, Frances,Dunlop, Noel F.
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- Biocompatible Ionic Liquid Promote One-Pot Synthesis of 2-Amino-4H-Chromenes Under Ambient Conditions
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Abstract: The synthesis of 2-amino-4H-chromenes through one-pot multicomponent reactions has received great attention due to the high atom efficiency and the broad bioactivities of the products. Here, the catalytic performances of a series of functional ionic liquids towards this type of reaction were investigated and the results showed that the ionic liquid, choline acetate ([Choline][Ac]), could efficiently promote this reactions under room temperature without the necessary of organic solvents. The reaction is easy to be conducted and the following work-up procedures are very simple. The pure products can be obtained through extraction and washing procedures, no column separation procedures are needed. Intriguingly, this reaction system can be easily scaled up to multi-gram, suggesting its perspective in industrial applications. In addition, the ionic liquid [Choline][Ac] can be easily prepared from cheap and biocompatible materials, and it can be feasibly recycled and reutilized for at least five cycles. Graphic Abstract: Various aldehydes, malononitrile and activated phenols could be converted to thecorresponding 2-amino-4H-chromenes with good to excellent isolated yields underthe catalysis of choline acetate at room temperature. [Figure not available: see fulltext.]
- Zhu, Anlian,Li, Qixing,Feng, Wanlu,Fan, Dongshuang,Li, Lingjun
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p. 720 - 733
(2020/08/07)
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- Binary Mixture of Double Protic Ionic Liquid: Density, Viscosity, Refractive Index, Surface Tension, and Derivative Properties
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This work presents density (ρ), dynamic viscosity (η), refractive index (nD), and surface tension (γ) experimental data for three pure protic ionic liquids: 2-hydroxyethylammonium acetate ([2-HEA][Ac]), bis(2-hydroxyethyl)ammonium acetate ([BHEA][Ac]), and bis(2 hydroxyethyl)ammonium butyric ([BHEA][Bu]), along with experimental data for two binary systems, as follows: ([2-HEA][Ac] + [BHEA][Ac]) and ([2-HEA][Ac] + [BHEA][Bu]), at a temperature range ofT= 278.15 to 343.15 K and atmospheric pressure (101.3 kPa). For the ([2-HEA][Ac] + [BHEA][Ac]) binary system, excess volume and refractive index deviation values are negative, while for the ([2-HEA][Ac] + [BHEA][Bu]) binary system are positive. For the first, there is a volume contraction, with higher probability of ion interactions. For the latter system, an expansive trend and lower ion interactions were found when compared to the ([2-HEA][Ac] + [BHEA][Ac]) system. Viscosity deviations values show a negative behavior for both binary systems studied. These results could indicate the predominance of dispersive forces. Furthermore, for the [2-HEA][Ac] + [BHEA][Ac] system, surface tension deviation values are positive. On the other hand, for the [2-HEA][Ac] + [BHEA][Bu] system this derivative property are negative. From these results, the [2-HEA][Ac] + [BHEA][Ac] binary system could be characterized by presenting prevalent dispersion forces and an unequal distribution of the mixture components between the bulk and interface.
- Buarque, Filipe S.,Camêlo, Lídia C. A.,Soares, Cleide M. F.,Mattedi, Silvana,Ferreira, Ailton F. B.,Feitosa, Filipe X.,Souza, Ranyere L.,de Sant’Ana, Hosiberto B.,Lima, álvaro S.
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p. 4309 - 4325
(2021/11/18)
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- Cytotoxicity of protic ionic liquids towards the HaCat cell line derived from human skin
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In this work we have investigated the toxicity of 10 PILs, consisting of ethyl-, ethanol-, diethanol- and triethanolammonium cations paired with nitrate, formate, acetate and glycolate anions. Their toxicity was quantified by the EC50 values of each of these PILs towards HaCat cells, which are derived from human skin cells. Additional salts and solvents were used for comparison including DMSO, choline chloride, potassium nitrate, sodium acetate and ethanol to distinguish if the toxicity changes were due to ionicity, short chain amphiphilic behaviour, or specific ion effects. The toxicity followed the general trend of choline chloride acetate containing PILs DMSO sodium acetate ethanol nitrate containing PILs or salt. Ethanolammonium acetate and ethylammonium acetate were identified as having the lowest toxicities of the PILs, being slightly more toxic than choline chloride or DMSO. Overall the toxicity was found to be highly dependent on the cation and anion combination, with the anion having a stronger affect. It was evident that the PILs can be tailored to vary their toxicities, and this is expected to be dependent on which cell lines are used.
- Abraham, Amanda N.,Arunkumar, Radhika,Drummond, Calum J.,Greaves, Tamar L.,Shukla, Ravi
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- The hydrophilic ionic liquid at room temperature and its use
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PROBLEM TO BE SOLVED: To provide a novel ionic liquid that is liquid at a room temperature and is hydrophilic, particularly water-soluble, and use thereof.SOLUTION: This invention provides a hydrophilic room-temperature ionic liquid including a cation and an anion, the cation being a quaternary ammonium cation of the formula (I), and the anion being a carboxylate anion, where R represents a 1-5C straight-chain or branched-chain alkylene group, and n represents an integer of 1-3.
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Paragraph 0105; 0106
(2019/09/11)
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- Hydroxyl alkyl ammonium ionic liquid assisted green and one-pot regioselective access to functionalized pyrazolodihydropyridine core and their pharmacological evaluation
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Herein our team explored a promising synthetic trail to Functionalized pyrazolodihydropyridine core using hydroxyl alkyl ammonium ionic liquid via one-pot fusion of 3-methyl-1-phenyl-1H-pyrazole-5-amine, different heterocyclic aldehydes and 1, 3-Cyclic diones. The aimed compounds were obtained by Domino-Knoevenagel condensation and Michael addition followed by cyclization. The reaction transformation involves the formation of two C–C and one C–N bond formation. The perspective of the present work is selectively approached to Functionalized pyrazolodihydropyridine core excluding other potential parallel reactions under environmentally benign reaction condition. The present protocol show features such as the low E-factor, ambiphilic behavior of ionic liquid during reaction transformation, scale-up to a multigram scale, reusability of the ionic liquid, mild reaction condition, and produce water as a byproduct. All newly derived compounds were evaluated for their in vitro biological activities. In preliminary biological studies compound, 4c showed better potency than the standard drug ampicillin against Gram-negative bacteria (E. coli); the compound 4i exhibited outstanding activity against S. aeruginosa which is far better than ampicillin, chloramphenicol, and ciprofloxacin. The compound 4m was found more potent against C. albicans, than that of griseofulvin and show equipotency to nystatin whereas, in preliminary antitubercular screening, compound 4o was exhibited more potency than rifampicin. Noteworthy compounds 4f and 4i were found most active in antiproliferative screening.
- Patel, Divyang M.,Sharma, Mayank G.,Vala, Ruturajsinh M.,Lagunes, Irene,Puerta, Adrián,Padrón, José M.,Rajani, Dhanji P.,Patel, Hitendra M.
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p. 137 - 150
(2019/01/30)
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- Micelle Formation of Protic Ionic Liquids in Aqueous Solution
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The ionic liquids potentialities to organize themselves in aqueous solution and produce aggregates were analyzed through the conductivity technique and after using a new mathematical model based on stochastic theories, to indicate the linearity change moment; it was possible to analyze the presence of these aggregates. It earns interest at science of colloids and interfacial chemistry due to the recognized ability of certain surfactant ionic liquids to reduce the surface tension of aqueous solutions and to aggregate in the form of micelles, even at low concentrations, allowing their use as stabilizing or destabilizing agents in homogeneous polymerization in water/oil emulsions. Within this context, this work aims to verify the possible micellar properties of the ionic liquids. Critical micellar concentration values for ions ammonium alkyl carboxylates were obtained. It was also shown that the CMC is directly related to the lipophilic groups of the cation and entropic factors.
- Santos, Dheiver
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p. 1480 - 1487
(2018/05/23)
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- Synthesis of high-density aviation fuels with methyl benzaldehyde and cyclohexanone
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A new two-step process was developed for the synthesis of high-density jet fuel range tricyclic alkanes with methyl benzaldehydes and cyclohexanone which can be derived from lignocellulose. In the first step, C14 oxygenates (i.e. 2-(2-methylbenzylidene)cyclohexanone or 2-(4-methylbenzylidene)cyclohexanone) were obtained by the solvent-free aldol condensation of 2-methyl benzaldehyde (or 4-methyl benzaldehyde) and cyclohexanone. Among the investigated catalysts, the EAOAc ionic liquid (a renewable catalyst which was prepared with ethanolamine and acetic acid) exhibited the highest activity and good stability for this reaction. Over it, high carbon yields (~85%) of C14 oxygenates were achieved under mild reaction conditions (353 K, 6 h). In the second step, the C14 oxygenates were selectively converted into 1-methyldodecahydro-1H-fluorene and 3-methyldodecahydro-1H-fluorene by the aqueous phase hydrodeoxygenation (APHDO) over a commercial Pd/C catalyst. According to our measurement, the 1-methyldodecahydro-1H-fluorene and 3-methyldodecahydro-1H-fluorene as obtained have high densities (0.99 g mL-1 and 0.96 g mL-1, respectively, at 298 K). As a potential application, they can be used as additives to improve the volumetric heat values of the current bio-jet fuels.
- Xu, Jilei,Li, Ning,Li, Guangyi,Han, Fengan,Wang, Aiqin,Cong, Yu,Wang, Xiaodong,Zhang, Tao
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p. 3753 - 3760
(2018/08/22)
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- Diethanolamine and N,N-diethylethanolamine ionic liquids as precatalyst-precursors and reaction media in green Heck reaction protocol
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It was found that Heck reaction with PdCl2 in diethanolamine and N,N-diethylethanolamine ionic liquids (ILs) is more efficient than analogous reactions performed in classical organic solvents. The used ILs facilitate solubility of the Pd(II) precatalysts, increase catalyst stability during the reaction, and function as reaction media, bases, precatalyst-precursors, good coordinating ligands, and mobile support for active Pd species. Thus, Heck reaction occurs without additional solvents, ligands and bases, that makes experimental procedure much simpler. Our DFT investigation provides mechanistic insight into the formation of the trans-[PdCl2(DEA)2] complex that acts as a precatalyst.
- Petrovi?, Zorica D.,Simijonovi??, Duica,Petrovi?, Vladimir P.,Markovi?, Svetlana
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experimental part
p. 45 - 50
(2010/11/16)
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- Nonadditivity of Faradaic currents and modification of capacitance currents in the voltammetry of mixtures of ferrocene and the cobaltocenium cation in protic and aprotic ionic liquids
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Unexpected nonadditivity of currents encountered in the electrochemistryof mixtures of ferrocene (Fc) and cobaltocenium cation (Cc+) as the PF6- salt has been investigated by direct current (dc) and Fourier-transformed alternating current (ac) cyclic vol tammetry in two aprotic (1-butyl-3-methylimidazolium tetrafluoroborate and 1-butyl-3-methylimidazolium hexafluorophosphate) and three protic (triethylammonium formate, bis(2-hydroxyethyl)ammonium acetate, and triethylammonium acetate) ionic liquids (ILs). The voltammetry of the individual Fc0/+ and Cc+/0 couples always exhibits near-Nernstian behavior at glassy carbon and gold electrodes. As expected for anideal process, the reversible formal potentials and diffusion coefficie nts at 23 ± 1°C in each IL determined from measurement on individual Fc and Cc+ solutions were found to be independent of electrode material, concentration, and technique used for the measurement. However, when Fc and Cc+ were simultaneously present, the dc and ac peak currents per unit concentration for the Fc0/+ and Cc+/0 processes were found to be significantly enhanced in both aprotic and protic ILs. Thus, the apparent diffusion coefficient values calculated for Fc and Cc+ were respectively found to be about 25 and 35percent larger than those determined individually in the aprotic ILs. A similar change in the Fc0/+ mass transport characteristics was observed upon addition of tetrabutylammonium hexafluorophosphate (Bu4NPF 6), and the double layer capacitance also varied in distinctly different ways when Fc and Cc+ were present individually or in mixtures. Importantly, the nonadditivity of Faradaic current is not associated with a change in viscosity or from electron exchange as found when some solutes are added to ILs. The observation that the 1H NMR T1 relaxation times for the proton resonance in Cc+ also are modified in mixed systems implies that specific interaction with aggregates of the constituentIL ionic species giving rise to subtle structural changes plays an impo rtant role in modifying the mass transport, double layer characteristics, and dynamics when solutes of interest in this study are added to ILs. Analogous voltammetric changes were not observed in studies in organic solvent media containing 0.1 M added supporting electrolyte. Implicationsof the nonadditivity of Faradaic and capacitance terms in ILs are consi dered.
- Shiddiky, Muhammad J. A.,Torriero, Angel A. J.,Zhao, Chuan,Burgar, Iko,Kennedy, Gareth,Bond, Alan M.
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supporting information; experimental part
p. 7976 - 7989
(2009/12/03)
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