- Hexahalometallate salts of trivalent scandium, yttrium and lanthanum: Cation-anion association in the solid state and in solution
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The hexahalide salts, [NnBu4]3[LaCl6], [BMPYRR]3[LaCl6] (BMPYRR = 1-butyl-1-methylpyrrolidinium), [EMIM]3[MX6] (EMIM = 1-ethyl-3-methylimidazolium; M = La, X = Cl, Br, I; M = Sc, Y, Ce, X = Cl) and [EDMIM]3[MX6] (EDMIM = 1-ethyl-2,3-dimethylimidazolium; M = Y, X = Cl; M = La, X = Cl, I) have been prepared and X-ray crystal structures determined for several of them, with a view to probing the effect of varying the trivalent metal ion, the halide and the counter-cation on the structures adopted in the solid state. The crystal structures of the EMIM and EDMIM salts show extensive H-bonding between the halide ligands and organic cations; based upon the H-bonding distances, this appears to be strongest for the [EMIM]3[MCl6] salts, becoming progressively weaker for heavier metal ion or halide. In terms of the cations, changing from EMIM to EDMIM also reduces the strength of the H-bonding. The strength of the cation-anion pairing in solution has also been probed in solution via NMR spectroscopy where possible (45Sc, 89Y and 189La) and, for the EMIM salts, via the shift of δ(H2) relative to [EMIM]Cl at a standard concentration. The trends observed in solution mirror those determined in the solid state.
- Champion, Martin J. D.,Levason, William,Pugh, David,Reid, Gillian
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- Synthesis of new hetero-arylidene-9(10H)-anthrone derivatives and their biological evaluation
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New hetero-arylidene-9(10H)-anthrone derivatives (1) were synthesized from reaction of 1,2-dimethyl-3-alkyl imidazolium salts (2) and 9-anthracenecarboxaldehyde. Ion exchange of the anion with dioctyl sulfosuccinate and lithium bis(trifluoromethanesulfonyl)imide led to the preparation of other derivatives. The antiproliferative effect of the compounds was evaluated in human ovarian (A2780) and colorectal (HCT116) carcinoma cell lines and in normal primary human fibroblasts. Compound 1 presented an antiproliferative effect related to the imidazolium pattern of substitution with compounds having a decyl group at the R-position (1c and 3c) showing the highest cytotoxic activities in all cell lines independently of the counter ion. Compounds 1b and 1c internalize A2780 cancer cells via a passive or an active transport, respectively, inducing A2780 cell death via an extrinsic apoptosis (1b) or intrinsic apoptosis and oncosis (1c). The localization of both compounds in the cytoplasm coupled to the absence of reactive oxygen species (ROS) induction suggest that the mechanisms of toxicity might be different than those of other anthracyclines currently used in chemotherapy.
- Baptista, Pedro V.,Branco, Paula S.,Fernandes, Alexandra R.,Malta, Gabriela,Peixoto, Daniela,Roma-Rodrigues, Catarina,Ferreira, Luísa M.
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- Ionic liquid containing electron-rich, porous polyphosphazene nanoreactors catalyze the transformation of CO2 to carbonates
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We show that ionic liquids (ILs) interact with electron-rich, porous polyphosphazene (PPZ), to form hybrid PPZ-IL nanoreactors able to simultaneously capture and transform CO2 into carbonates. The PPZ nanospheres swell in organic solvents and e
- Huang, Zhangjun,Uranga, Jorge G.,Zhou, Shiliu,Jia, Haiyan,Fei, Zhaofu,Wang, Yefeng,Bobbink, Felix D.,Lu, Qinghua,Dyson, Paul J.
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- Alkali stability excellent imidazole and imidazolium cation
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and membranes and devices comprising the polymers. Also provided are methods of making the inventive compounds and polymers.
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Paragraph 0243-0244; 0299-0301
(2018/04/13)
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- Developments in the Reactivity of 2-Methylimidazolium Salts
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Unexpected and unusual reactivity of 2-methylimidazolium salts toward aryl-N-sulfonylimines and aryl aldehydes is here reported. Upon reaction with aryl-N-sulfonylimines, the addition product, arylethyl-2-imidazolium-1-tosylamide (3), is formed with moderate to good yields, while upon reaction with aldehydes, the initial addition product (6) observed in NMR and HPLC-MS experimental analysis is postulated by us as an intermediate to the final conversion to carboxylic acids. Studies in the presence and absence of molecular oxygen allow us to conclude that the imidazolium salts is crucial for the oxidation. A detailed mechanistic study was carried out to provide insights regarding this unexpected reactivity.
- Peixoto, Daniela,Figueiredo, Margarida,Gawande, Manoj B.,Corvo, Marta C.,Vanhoenacker, Gerd,Afonso, Carlos A.M.,Ferreira, Luisa M.,Branco, Paula S.
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p. 6232 - 6241
(2017/06/23)
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- Imidazolium Cations with Exceptional Alkaline Stability: A Systematic Study of Structure-Stability Relationships
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Highly base-stable cationic moieties are a critical component of anion exchange membranes (AEMs) in alkaline fuel cells (AFCs); however, the commonly employed organic cations have limited alkaline stability. To address this problem, we synthesized and characterized the stability of a series of imidazolium cations in 1, 2, or 5 M KOH/CD3OH at 80 °C, systematically evaluating the impact of substitution on chemical stability. The substituent identity at each position of the imidazolium ring has a dramatic effect on the overall cation stability. We report imidazolium cations that have the highest alkaline stabilities reported to date, >99% cation remaining after 30 days in 5 M KOH/CD3OH at 80 °C.
- Hugar, Kristina M.,Kostalik, Henry A.,Coates, Geoffrey W.
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supporting information
p. 8730 - 8737
(2015/07/27)
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- Convenient syntheses of bulky group containing imidazolium ionic liquids
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We report syntheses of bulky group containing imidazolium based ionic liquids. The bulky groups were introduced at N-1, C-2, and N-3 positions of the imidazole ring using convenient methodologies. Copyright
- Kumar, Neeraj,Jain, Rahul
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experimental part
p. 370 - 374
(2012/06/04)
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