- Synthesis of Organic (Trimethylsilyl)chalcogenolate Salts Cat[TMS-E] (E = S, Se, Te): the Methylcarbonate Anion as a Desilylating Agent
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A high-yield synthesis of the class of (trimethylsilyl)chalcogenolate organic salts [Cat][TMS-E] (E = S, Se, Te; Cat = BMPyr, DMPyr, NMe4, nBu3MeP) is presented. The title compounds have been prepared by the strictly aprotic reaction between the respective bis(trimethylsilyl)chalcogenide (TMS2E) and methylcarbonate ionic liquids (ILs). This constitutes a novel reaction behavior of methylcarbonate ILs, acting as a nucleophilic desilylating agent and a Lewis base instead of as a Bronsted base. Thus prepared silylchalcogenolate salts represent an activated form of the multifunctional TMS2E reactant series. Pyrrolidinium TMS-S salts have proven to be excellent precursors for the synthesis of pyrrolidinium hexasulfides. The scope of the desilylation reaction can be extended to other silyl-bearing synthons such as (trimethylsilyl)azide and (trimethylsilyl)cyanide.
- Finger, Lars H.,Scheibe, Benjamin,Sundermeyer, J?rg
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Read Online
- A method for preparing ionic liquid
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The invention provides a preparation method for an ionic liquid. The method comprises the following steps: a, reacting a tertiary amine compound, tertiary imine compound or tertiary phosphorus compound with carbonate so as to obtain an intermediate containing quaternary ammonium cation or quaternary phosphorus cation; and b, reacting the intermediate produced in the step a with an imine compound, or subjecting the intermediate produced in the step a to hydrolysis at first and then to a reaction with the imine compound or an imine salt. The imine type quaternary ammonium or quaternary phosphorus ionic liquid prepared by using the method is especially applicable to a halide-ion-sensitive electrochemical system, e.g., a lithium ion secondary battery and an electrochemical super capacitor. According to the method, raw materials are non-toxic and harmless; reaction conditions are mild; requirements on production equipment are not high; all the conventional reaction vessels applicable to liquid phase reactions can be used in principle; and operations like feeding, mixing, distilling and filtering are simple.
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Paragraph 0082; 0083
(2018/01/11)
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- The reaction of primary aromatic amines with alkylene carbonates for the selective synthesis of bis-N-(2-hydroxy)alkylanilines: The catalytic effect of phosphonium-based ionic liquids
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At T ≥ 140 °C, different primary aromatic amines (pX-C 6H4NH2; X = H, OCH3, CH3, Cl) react with both ethylene- and propylene-carbonates to yield a chemoselective N-alkylation process: bis-N-(2-hydroxyalkyl)anilines [pX-C 6H4N(CH2CH(R)OH)2; R = H, CH 3] are the major products and the competitive formation of carbamates is substantially ruled out. At 140 °C, under solventless conditions, the model reaction of aniline with ethylene carbonate goes to completion by simply mixing stoichiometric amounts of the reagents. However, a class of phosphonium ionic liquids (PILs) such as tetraalkylphosphonium halides and tosylates turn out to be active organocatalysts for both aniline and other primary aromatic amines. A kinetic analysis monitored by 13C NMR spectroscopy, shows that bromide exchanged PILs are the most efficient systems, able to impart a more than 8-fold acceleration to the reaction. The reactions of propylene carbonate take place at a higher temperature than those of ethylene carbonate, and only in the presence of PIL catalysts. A mechanism based on the Lewis acidity of tetraalkylphosphonium cations and the nucleophilicity of halide anions has been proposed to account for both the reaction chemoselectivity and the function of the catalysts.
- Selva, Maurizio,Fabris, Massimo,Lucchini, Vittorio,Perosa, Alvise,Noe, Marco
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experimental part
p. 5187 - 5198
(2010/12/25)
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- Electrochemically stable onium salts and electrolytes containing such for electrochemical capacitors
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Based on the discovery that the melting point and solubility of onium salts are affected by the asymmetry of the substitution on cation, and that the branched substituents effectively shield onium cations from electrochemical reduction, new onium salts are synthesized and high performance electrolytes based on these salts for electrochemical capacitor are provided. The composition of the new electrolyte comprises an onium salt or mixture of such onium salts dissolved in aprotic, non-aqueous solvents or mixture of such solvents. The electrolyte is able to perform at high rate of charge/discharge, at low ambient temperatures, and within wide operating voltage, due to the high solubility, low melting temperature, and the improved reduction stability of the new onium cations, respectively.
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Page column 10
(2008/06/13)
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