35935-34-3Relevant academic research and scientific papers
Upon the Structure of Room Temperature Halogenoaluminate Ionic Liquids
Abdul-Sada, Ala'a K.,Greenway, Anthony M.,Hitchcock, Peter B.,Mohammed, Thamer J.,Seddon, Kenneth R.,Zora, Jalal A.
, p. 1753 - 1754 (1986)
The X-ray structure of a monoclinic crystal of 1-methyl-3-ethylimidazolium iodide, I, reveals the presence of discrete hydrogen-bonded ion-pairs I(1-)> = 0.293 nm>: the structural implications of the presence of hydrogen-bonding in ionic liquids based upon X-AlX3 (X = Cl or Br) mixtures are discussed.
Evidence for Hydrogen Bonding in Solution of 1-Ethyl-3-methylimidazolium Halides, and its Implications for Room-temperature Halogenoaluminate(III) Ionic Ligands
Avent, Anthony G.,Chaloner, Penelope A.,Day, Martin P.,Seddon, Kenneth R.,Welton, Thomas
, p. 3405 - 3414 (1994)
Multinuclear NMR spectroscopy and conductivity measurements showed that the 1-ethyl-3-methylimidazolium cation, (1+), not only forms strong hydrogen bonds (using all three ring protons H2, H4 and H5) with halide ions in polar molecular solvents (e.g. ethanenitrile) and ionic liquids, but that it exists in a quasi-molecular state, X, in non-polar solvents (e.g. trichloro- and dichloromethane), showing a conventional aromatic stacking phenomenon.
Kinetics of the synthesis of 1-alkyl-3-methylimidazolium ionic liquids in dilute and concentrated solutions
Firaha, Dzmitry S.,Paulechka, Yauheni U.
, p. 771 - 779 (2013)
The kinetics of the reactions of 1-methylimidazole with iodoethane, 1-iodobutane, 1-bromobutane, 1-bromohexane, 1-bromooctane resulting in the formation of corresponding 1-alkyl-3-methylimidazolium halide ionic liquids in acetonitrile and cyclopentanone solutions has been studied in a wide range of concentrations and degrees of conversion. The studied reactions were found to follow the SN2 rate law in the dilute solutions. The significant deviations from the simple SN2 rate law observed at higher concentrations of the reactants were assigned to the concentration dependence of activity coefficients for the reactants and the transition states. The experimental data were processed with the conductor-like screening model-segment activity coefficient (COSMO-SAC) model and the Scatchard-Hildebrand equation. The latter was found to provide somewhat better description of the experimental results; however, the former has a wider predictive ability. The Arrhenius activation energies and the activation enthalpies were calculated for the investigated systems. The rate constants at infinite dilution were obtained for a large number of 1-haloalkane + 1-methylimidazole + solvent systems with the use of the COSMO-SAC model. It was demonstrated that the rate constants of the studied reactions in various non-hydrogen-bonding solvents can be estimated from a correlation with the Hildebrand solubility parameter.
Neoteric optical media for refractive index determination of gems and minerals
Deetlefs, Maggel,Seddon, Kenneth R.,Shara, Michael
, p. 317 - 326 (2006)
Refractive index determination of minerals and gems often requires their immersion in fluids with the same refractive index. However, these natural materials frequently have refractive indices above the ranges of common organic solvents. Most available high refractive index immersion materials are solid at room temperature, toxic, noxious, corrosive, carcinogenic, or any combination thereof. Since the physical properties of ionic liquids can be tuned by varying the cation and/or anion, we have developed immersion fluids for mineralogical studies which are relatively benign. We report here the syntheses of a range of ionic liquids (many novel) based on the 1-alkyl-3-methylimidazolium cation, which all have refractive indices greater than 1.4, and can be used as immersion fluids for optical mineralogy studies. We further show that for a series of ionic liquids with the same anion, the refractive indices can be adjusted by systematic changes in the cation. the Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2006.
Ionic liquids containing plant derived benzoate as anions, exhibiting supramolecular polymeric aggregation: Impact of the aggregation on organic catalysis in aqueous medium
Javed, Muhammad Naveed,Ali Hashmi, Imran,Muhammad, Shoaib,Bari, Ahmed,Ghulam Musharraf, Syed,Junaid Mahmood, Syed,Javed, Saima,Imran Ali, Firdous,Rafique, Faisal,Amjad Ilyas, Muhammad,Ahmed Waseem, Waqas
, (2021/05/10)
Naturally occurring benzoic acid (BA) derived anions have been used to prepare halogen free hydrophilic ionic liquids (ILs 1–4). The supramolecular polymeric aggregation behaviour of these ILs has been studied through high-resolution electron spray ioniza
Photocatalytic C-F Bond Borylation of Polyfluoroarenes with NHC-boranes
Chen, Kai,Chen, Xiao-Qing,Hu, Yuan-Zhuo,Xia, Peng-Ju,Xiang, Hao-Yue,Xiao, Jun-An,Yang, Hua,Ye, Zhi-Peng
supporting information, p. 1742 - 1747 (2020/03/24)
The first photoredox-catalyzed defluoroborylation of polyfluoroarenes with NHC-BH3 has been facilely achieved at room temperature via a single-electron-transfer (SET)/radical addition pathway. This new strategy makes full use of the advantage of photoredox catalysis to generate the key boryl radical via direct activation of a B-H bond. Good functional group tolerance and high regioselectivity offer this protocol incomparable advantages in preparing a wide array of valuable polyfluoroarylboron compounds. Moreover, both computational and experimental studies were performed to illustrate the reaction mechanism.
Bidentate cation-anion coordination in the ionic liquid 1-ethyl-3-methylimidazolium hexafluorophosphate supported by vibrational spectra and NBO, AIM and SQMFF calculations
Assenine, Mohammed Amin,Brandán, Silvia Antonia,Bresson, Serge,Haddad, Boumediene,Paolone, Annalisa,Villemin, Didier
, (2020/04/08)
Experimental attenuated total reflectance (ATR) and Raman spectra for the synthesized ionic liquid 1-Ethyl-3-methylimidazolium hexafluorophosphate [EMIM+][PF6 ?] have been combined with the functional hybrid B3LYP and the 6-31G? and 6-311++G?? basis sets in order to evaluate the coordination mode of [PF6 ?] anion and determine the its structural, electronic, topological and vibrational properties. The scaled quantum mechanical force fields (SQMFF) methodology allowed us to obtain a set of scaled force constants fitting the observed wavenumbers because, so far, they have not reported. Experimental ATR and Raman spectra for the ionic liquid [EMIM+][PF6 ?] in the solid phase are consistent with the corresponding predicted by using both levels of theory. Here, complete vibrational assignments of 72 normal modes of vibration expected for ionic liquid were performed by using B3LYP/6-311++G?? level and considering that the [PF6 ?] anion adopts a bidentate coordination mode. Atomic Merz-Kollman (MK) charges and bond orders studies have revealed a distorted octahedral symmetry of anion in the ionic liquid and have suggested bidentate coordination of anion by two C–H?F hydrogen bonds, as experimentally was also proposed. Natural bond orbital (NBO) and atoms in molecules (AIM) calculations support the high stability of ionic liquid and its high dipole moment value. Frontier orbitals for the three species show that the [PF6 ?] anion increases the reactivity of ionic liquid. Here, we determine that the B3LYP/6-311++G?? molecular force field for the ionic liquid [EMIM+][PF6 ?] with the bidentate coordination mode adopted by [PF6 ?] anion is well represented, as also was supported by the scaled force constants calculated for both C–H?F hydrogen bonds.
Eutectic ionic liquids as potential electrolytes in dye-sensitized solar cells: Physicochemical and conductivity studies
Kurnia, Kiki Adi,Mohd Faridz Hilmy, Nurfathiah Izzaty,Yahya, Wan Zaireen Nisa
, (2020/10/06)
Ionic liquids (ILs) have been introduced as the electrolyte in dye-sensitized solar cells (DSSC) to replace organic solvents due to their non-flammability, chemical, and thermal stability, as well as less prone to evaporation and leakage. A series of eutectic ILs mixtures composed of 1-ethyl-3-methylimidazolium iodide, [C2C1im]I, 1-ethylpyridinium iodide [C2py]I, 1-propylpyridinium iodide, [C3py]I and 1-butylpyridinium iodide, [C4py]I was developed. The structures and purity of the compounds were validated by nuclear magnetic resonance and Karl Fischer Titration. Their physicochemical properties, such as viscosities and ionic conductivities were evaluated for their potential use as electrolytes in DSSCs. The melting temperature of pure ionic liquids and the mixtures were determined using differential scanning calorimetry in the temperature range of 123.15 K to 393.15 K. It is found that eutectic mixtures were formed at the molar ratios of {0.75[C2py]I:0.25[C2C1im], {0.25[C2py]I:0.75[C2C1im]I}, {0.50[C2py]I:0.50[C2C1im]I}, {0.25[C2C1im]I:0.75 [C4py]I}, {0.75[C2C1im]I:0.25[C4py]I}, and {0.50[C2C1im]I:0.50[C4py]I} with the latter forming a highly stable liquid with no apparent melting peak in the studied temperature range. To understand the formation of eutectic composition, a correlation between molecular structures and the interaction energies of the cations and anions of ILs was performed using the Conductor-like Screening Model for Real Solvents (COSMO-RS). Dynamic viscosities of the binary mixtures were evaluated in the temperature range of 283.15 K to 353.15 K with 10 K increment. The highest ionic conductivity was exhibited by the eutectic ILs electrolyte {0.50[C2C1im]I:0.50[C4py]I:I2(50 wt%)} at 9.67 mS·cm?1 showing its potential for electrolyte application in DSSC.
Ionic Liquids Catalyzed Friedel–Crafts Alkylation of Substituted Benzenes with CCl4 Toward Trichloromethylarenes
Lyu, Xinyu,Wang, Wencheng,Sun, Yiqun,Zhao, Qian,Qiu, Tao
, p. 665 - 671 (2019/01/04)
Abstract: An ionic liquid catalyzed Friedel–Crafts alkylation reaction of substituted benzenes with CCl4 was developed. The reaction proceeded efficiently under mild conditions, gave corresponding trichloromethylarenes with diversity functional groups in moderate to good yields. The influence of Lewis acidity of ionic liquids on the conversion of the alkylation reaction has been investigated. Notably, the probable mechanism of this reaction has been proposed with the assistance of 27Al NMR spectroscopy. It was noteworthy that the predominance of [Al2Cl7]? species in EmimCl–AlCl3, N = 0.67 could be detected by 27Al NMR spectral analysis, and [AlCl4]? was generated at the beginning of reaction. Additionally, it was found that [AlCl4]? could be transformed into [Al2Cl7]? when the reaction finished. Some control experiments confirmed that the interaction between Lewis acidic species [Al2Cl7]? of the ionic liquid and CCl4 led to the change in speciation of aluminum during the alkylation reactions. Graphical Abstract: [Figure not available: see fulltext.].
Towards Safer Rocket Fuels: Hypergolic Imidazolylidene-Borane Compounds as Replacements for Hydrazine Derivatives
Huang, Shi,Qi, Xiujuan,Liu, Tianlin,Wang, Kangcai,Zhang, Wenquan,Li, Jianlin,Zhang, Qinghua
, p. 10187 - 10193 (2016/07/19)
Currently, toxic and volatile hydrazine derivatives are still the main fuel choices for liquid bipropellants, especially in some traditional rocket propulsion systems. Therefore, the search for safer hypergolic fuels as replacements for hydrazine derivatives has been one of the most challenging tasks. In this study, six imidazolylidene-borane compounds with zwitterionic structure have been synthesized and characterized, and their hypergolic reactivity has been studied. As expected, these compounds exhibited fast spontaneous combustion upon contact with white fuming nitric acid (WFNA). Among them, compound 5 showed excellent integrated properties including wide liquid operating range (?70–160 °C), superior loading density (0.99 g cm?3), ultrafast ignition delay times with WFNA (15 ms), and high specific impulse (303.5 s), suggesting promising application potential as safer hypergolic fuels in liquid bipropellant formulations.
