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Oxidation ionic liquid

Organoboron compound, geminal, 219 Organodiboron derivatives, 193 Organodielement halides, 79-83 Organoelement halides, 99 Os-Cl exchange, 186 Osmium boryl complexes, 179 Oxidation, ionic liquids, 278-279... [Pg.288]

Borodin, O. Smith, G. D. Geiculescu, O. Creager, S. E. Hallac, B. DesMarteau, D., LB Transport in Lithium Sulfonylimide-01igo(Ethylene Oxide) Ionic Liquids and OUgo(Ethylene Oxide) Doped with Litfsi. J. Phys. Chem. B 2006,110, 24266-24274. [Pg.398]

Borodin O et al (2006) Li Transport in lithium sulfonylunide-oligo(ethylene oxide) ionic liquids and oligo(ethylene oxide) doped with LiTFSI. J Phys Chem B 110 24266... [Pg.234]

Zhao, D. S. Liu, R. Wang, J. L. Liu, B. (2008). Photochemical oxidation-ionic liquid extraction coupling technique in deep desulphurization of light oil. Energy Fuels, 22, 1100-1103, ISSN 0887-0624. [Pg.629]

The all-decisive requirement for the fractionation by means of CPF consists of the availability of a suitable solvent enabling the realization of liquid-liquid equilibria. For some polymers, such solvents are unknown. In such cases, it is possible to evade this issue by transforming the polymer into a soluble derivative. This strategy has been applied to cellulose although several direct solvents for cellulose (e.g., N-methylmorpholine-N-oxide, ionic liquids, and dimethylacetamide (DMAc) plus liCl) exist, it is probably more economic to realize the fractionation through the derivatives. Two such products, hydroxylethyl cellulose and trimethylsilylcellulose, ° have been fractionated by means of CPF. For hydroxylethyl cellulose water was used as solvent and THF served as nonsolvent, while toluene and dimethyl sulfoxide were used in the case of trimethylsilylcellulose. [Pg.71]

A key criterion for selection of a solvent for electrochemical studies is the electrochemical stability of the solvent [12]. This is most clearly manifested by the range of voltages over which the solvent is electrochemically inert. This useful electrochemical potential window depends on the oxidative and reductive stability of the solvent. In the case of ionic liquids, the potential window depends primarily on the resistance of the cation to reduction and the resistance of the anion to oxidation. (A notable exception to this is in the acidic chloroaluminate ionic liquids, where the reduction of the heptachloroaluminate species [Al2Cl7] is the limiting cathodic process). In addition, the presence of impurities can play an important role in limiting the potential windows of ionic liquids. [Pg.104]

It must be noted that impurities in the ionic liquids can have a profound impact on the potential limits and the corresponding electrochemical window. During the synthesis of many of the non-haloaluminate ionic liquids, residual halide and water may remain in the final product [13]. Halide ions (Cl , Br , I ) are more easily oxidized than the fluorine-containing anions used in most non-haloaluminate ionic liquids. Consequently, the observed anodic potential limit can be appreciably reduced if significant concentrations of halide ions are present. Contamination of an ionic liquid with significant amounts of water can affect both the anodic and the cathodic potential limits, as water can be both reduced and oxidized in the potential limits of many ionic liquids. Recent work by Schroder et al. demonstrated considerable reduction in both the anodic and cathodic limits of several ionic liquids upon the addition of 3 % water (by weight) [14]. For example, the electrochemical window of dry [BMIM][BF4] was found to be 4.10 V, while that for the ionic liquid with 3 % water by weight was reduced to 1.95 V. In addition to its electrochemistry, water can react with the ionic liquid components (especially anions) to produce products... [Pg.104]

Singer and Scammells have investigated the y-Mn02 oxidation of codeine methyl ether (CME) to thebaine in the ionic liquid [BMIM][BF4] [63]. The ionic liquid was used in different ways and with mixed results (Scheme 5.1-35). For example, the oxidation of CME in the ionic liquid gave 38 % yield after 120 hours. A similar reaction under biphasic conditions (with diethyl ether) gave a 36 % yield of thebaine. This reaction gave a 25 % yield of thebaine when carried out in tetrahydrofuran... [Pg.190]

As well as this quite obvious environmental aspect, the switch from a volatile, flammable, organic solvent to an ionic liquid may significantly improve the safety of a given process. This will be especially true in oxidation reactions in which air or pure oxygen are used as oxidants the use of common organic solvents is often restricted due to the potential formation of explosive mixtures between oxygen and... [Pg.217]

Another means of in situ metal-carbene complex formation in an ionic liquid is the direct oxidative addition of the imidazolium cation to a metal center in a low oxidation state (see Scheme 5.2-2, route b)). Cavell and co-workers have observed oxidative addition on heating 1,3-dimethylimidazolium tetrafluoroborate with Pt(PPli3)4 in refluxing THF [32]. The Pt-carbene complex formed can decompose by reductive elimination. Winterton et al. have also described the formation of a Pt-car-bene complex by oxidative addition of the [EMIM] cation to PtCl2 in a basic [EMIM]C1/A1C13 system (free CP ions present) under ethylene pressure [33]. The formation of a Pt-carbene complex by oxidative addition of the imidazolium cation is displayed in Scheme 5.2-4. [Pg.224]

Catalytic oxidation reactions in ionic liquids have been investigated only very recently. This is somewhat surprising in view of the well loiown oxidation stability of ionic liquids, from electrochemical studies [11], and the great commercial importance of oxidation reactions. Moreover, for oxidation reactions with oxygen, the nonvolatile nature of the ionic liquid is of real advantage for the safety of the reaction. While the application of volatile organic solvents may be restricted by the formation of explosive mixtures in the gas phase, this problem does not arise if a nonvolatile ionic liquid is used as the solvent. [Pg.232]

The oxidation of alkenes and allylic alcohols with the urea-EL202 adduct (UELP) as oxidant and methyltrioxorhenium (MTO) dissolved in [EMIM][BF4] as catalyst was described by Abu-Omar et al. [61]. Both MTO and UHP dissolved completely in the ionic liquid. Conversions were found to depend on the reactivity of the olefin and the solubility of the olefinic substrate in the reactive layer. In general, the reaction rates of the epoxidation reaction were found to be comparable to those obtained in classical solvents. [Pg.233]

Finally, it should be mentioned that ionic liquids have successfully been used in classical, stoichiometric oxidation reactions as well. Singer et al., for example, described the application of [BMIM][Bp4] in the oxidation of codeine methyl ether to thebaine [64]. The ionic liquid was used here as a very convenient solvent to extract excess Mn02 and associated impurities from the reaction mixture. [Pg.234]

The ease of formation of the carbene depends on the nucleophilicity of the anion associated with the imidazolium. For example, when Pd(OAc)2 is heated in the presence of [BMIM][Br], the formation of a mixture of Pd imidazolylidene complexes occurs. Palladium complexes have been shown to be active and stable catalysts for Heck and other C-C coupling reactions [34]. The highest activity and stability of palladium is observed in the ionic liquid [BMIM][Brj. Carbene complexes can be formed not only by deprotonation of the imidazolium cation but also by direct oxidative addition to metal(O) (Scheme 5.3-3). These heterocyclic carbene ligands can be functionalized with polar groups in order to increase their affinity for ionic liquids. While their donor properties can be compared to those of donor phosphines, they have the advantage over phosphines of being stable toward oxidation. [Pg.269]

It was quite recently reported that La can be electrodeposited from chloroaluminate ionic liquids [25]. Whereas only AlLa alloys can be obtained from the pure liquid, the addition of excess LiCl and small quantities of thionyl chloride (SOCI2) to a LaCl3-sat-urated melt allows the deposition of elemental La, but the electrodissolution seems to be somewhat Idnetically hindered. This result could perhaps be interesting for coating purposes, as elemental La can normally only be deposited in high-temperature molten salts, which require much more difficult experimental or technical conditions. Furthermore, La and Ce electrodeposition would be important, as their oxides have interesting catalytic activity as, for instance, oxidation catalysts. A controlled deposition of thin metal layers followed by selective oxidation could perhaps produce cat-alytically active thin layers interesting for fuel cells or waste gas treatment. [Pg.300]

Many organic chemical transformations have been carried out in ionic liquids hydrogenation [4, 5], oxidation [6], epoxidation [7], and hydroformylation [8] reactions, for example. In addition to these processes, numerous synthetic routes involve a carbon-carbon (C-C) bond-forming step. As a result, many C-C bondforming procedures have been studied in ambient-temperature ionic liquids. Among those reported are the Friedel-Crafts acylation [9] and allcylation [10] reactions, allylation reactions [11, 12], the Diels-Alder reaction [13], the Heck reaction [14], and the Suzuld [15] and Trost-Tsuji coupling [16] reactions. [Pg.319]

Another iron porphyrin complex with 5,10,15,20-tetrakis(2, 6 -dichloro-3 -sulfonatophenyl)porphyrin was applied in ionic liquids and oxidized veratryl alcohol (3,4-dimethoxybenzyl alcohol) with hydrogen peroxide in yields up to 83% to the aldehyde as the major product [145]. In addition, TEMPO was incorporated via... [Pg.103]


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See also in sourсe #XX -- [ Pg.153 , Pg.291 ]




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Benzylic alcohols, oxidation ionic liquid

Imidazolium ionic liquids, oxidation

Ionic liquid oxide cathodes

Liquid oxidizer

Metal oxide-ionic liquid interface

Oxides ionic

Oxidizing liquid

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