Imidazolium methyl

FIG. 11 Titration plot of alkanesulfonates. Sample 60 wt % of Hostapur SAS 60, monosulfonates fraction contents ca. 140 mg/100 ml (10% MeOH) solution to be titrated 10 ml, 5 ml buffer pH 3 (Merck), 5 ml MeOH, diluted to 100 ml with water titrant 0.004 mol/l TEGOtrant A 100 (l,3-didecyl-2-methyl-imidazolium chloride, Metrohm 6.2317.000) titrator Titrino 716 DMS with automatic titrator 727 and propellant stirrer titration mode dynamic end point titration (DET), high-sense electrode Metrohm 6.0504.15Q, reference electrode Ag/AgCl Metrohm 6.0733.100, EP = end point. 

Coupling one of these cations with one of these anions gives an ionic molecule that has high electron density at the anionic end. The computer image at top right shows this for butyl methyl imidazolium hexafluorophosphate. 

Figure 5.23 Ring of 48 tip-generated Fe clusters on Au(1 1 1) in l-butyl-3-methyl-imidazolium BF4 + approximately 50mM FeCl3. (Reproduced with permission from Ref. [95].)...

As reported by Griengl and coworkers, benzaldehyde, decanal, undecanal, and dodecanal were reacted with HCN in a two-phase solvent system aqueous buffer and ionic liquids 1 -ethyl-3-methylimidazolium tetrafluoroborate, 1 -methyl-3-propylimidazolium tetrafluoroborate, and l-butyl-3-methyl-imidazolium tetrafluoroborate in the presence of the HNLs from Prunus amygdalus and Hevea brasiliensis. When compared with the use of organic solvents as the nonaqueous phase, the reaction rate was significantly increased and the enantioselectivity remained good [51]. 

To introduce the Rh-centre in the supported ionic liquid, a solution of [Rh(CO)2(acac)] in acetonitrile was treated with either the ligand tri(m-sulfonyl)triphenyl phosphine trisodium salt (TPPTS) or the ligand tri(m-sulfonyl)triphenyl phosphine tris(l- butyl-3-methyl-imidazolium) salt (TPPTI) (Rh/P ratio of 1 10). The ligand TPPTI was found to dissolve in [BMIM][BF4] and... 

Full dissolution has been reported to proceed in ionic liquids such as butyl- or allyl-methyl-imidazolium chloride under microwave irradiation [59, 60], The Clanton is claimed to be essential to favor the de-agglomerization of the cellulose by breaking its H-bonds that hold it together [61]. The cellulose can subsequently be precipitated from the ionic liquid upon addition of, for example, water, without significant depolymerization. 

Interestingly, catalyst 3a showed higher racemization activities in ionic liquids such as [EMlm]BF4 and [BMlm]PF,5 ([EMlm]=l-ethyl-3-methylimidazolium, [BMlm]=l-butyl-3-methyl-imidazolium) [19]. The DKR in ionic liquids has one big... 

Application may be found for ionic liquids of resonance-stabilized methanides which can easily be prepared from the alkali salts. The first synthetic step includes the formation of the nearly insoluble silver salts in water (AgX, X = methanide). Since the silver salts dissolve in 2N aqueous NH3, adding ethyl(methyl)imidazolium bromide (EMHBr") results in the formation of a water-soluble ethyl(methyl)imidazolium methanide (EMHX") which can be separated from the AgBr precipitate by filtration. ... 

Stabilized by bulky organic cations such as EMI+ or BMI+ [BMI+ = butyl(methyl) imidazolium]. Nitrosomethanide-based ionic liquids are very hygroscopic and immediately absorb water when exposed to air. The experimentally determined melting points vary between —4°C and 35 °C (Figure 40, Table 11), with the BMI+ salts always possessing the lower melting point. ... 

The cations in ionic liquids are generally bulky monovalent organics. The typical cations of ionic liquids, not including the familiar alkylammonium and alkylphosphonium ions, are shown in Fig. 2. It is primarily the cations, which account for the low melting points of ionic liquids. The dialkylimidazolium ions, such as 1-butyl-3-methyl imidazolium [BMIM], have been widely investigated because low-melting ionic liquids can be made readily from such cations and because of their thermal and chemical stability. 

It has been noted that imidazolium ions are not inert. Under mild basic conditions, they are deprotonated to give reaetive nucleophiles. For reactions in basic media, the C2 hydrogen of the imidazolium ring can be replaced with an alkyl group. In one study, the C2 hydrogen was substituted by a methyl group. Ionie liquids based on the C2 methylated imidazolium cation were evaluated for the... 

An ionic liquid was fully immobilized, rather than merely supported, on the surface of silica through a multiple-step synthesis as shown in Fig. 15 (97). A ligand tri(m-sulfonyl)triphenyl phosphine tris(l-butyl-3-methyl-imidazolium) salt (tppti) was prepared so that the catalyst, formed from dicarbonylacetylacetonate rhodium and the ligand (P/Rh = 10), could be soluble in both [BMIMJBFq and [BMIM]PF6. The supported ionic liquid-catalyst systems showed nearly three times higher rate of reaction (rate constant = 65 min ) that a biphasic system for the hydroformylation of 1-hexene at 100°C and 1500 psi in a batch reactor, but the n/i selectivity was nearly constant the same for the two ( 2.4). Unfortunately, both the supported and the biphasic ionic liquid systems exhibited similar metal leaching behavior. 

PREPARATION OF 1-BUTYL-3-METHYL IMIDAZOLIUM-BASED ROOM TEMPERATURE IONIC LIQUIDS... 

According to the nature of their counter anion, ionic liquids (ILs) can dissolve a large amount of carbohydrates. In 2003, Moreau and co-workers reported the acid-catalyzed dehydration of fructose in a microbatch reactor at 80°C using l-butyl-3-methyl imidazolium tetrafluoroborate (BM1M BF4 ) (hydrophilic), and l-butyl-3-methyl imidazolium hexafluorophosphate (BMIM Fe (hydrophobic) (Scheme 10) [95]. 

Aerobic oxidation of primary alcohols to aldehydes and secondary alcohols to ketones was accomplished in ionic liquids (bmim, l-butyl-3-methyl-imidazolium cation) as RuCl2(PPh3)j/(bmim)V80°C RuClj or [RuCl Cp-cymene)] were also used... 

The imidazolium compounds l-ethyl-3-methyl-imidazolium-chloride (EMIM-Cl), l-butyl-3-methyl-imidazolium-chloride (n-BuMIM-Cl), and l-hexyl-3-methyl-imidazolium-chloride (n-HeMIM-Cl), toluene (anhydrous, 99.99%), and HCl were obtained from Sigma Aldrich whereas, l-octyl-3-methyl-imidazolium-chloride (n-OcMIM-Cl), l-Dodecyl-3-methyl-imidazolium-chloride (n-DoMIM-Cl) were... 

Dihydroimidazo[2,l-b]oxazoles were prepared fi om an intramolecular nucleophilic ipso-substitution of 2-alkylsulfonylimidazoles <99S1613>. The synthesis of hitherto unknown 2-(2,4,6-triarylphenyl)substituted 4,5-dihydro-1/f-imidazolium perchlorates from 2-methyl imidazolium perchlorates and 2,4,6-triarylpyrylium perchlorate salts was published <99JC813>. Substituted aromatic heterocycles from reactions of 2,3-dihydrospiro[l/f-4-and... 

Die Herstellung von 2-Chlor-4-methyl-imidazolium-chloriden durch Cyclisierung von N-(2-Propinyl)-harnstoffen mit Phosphor(V)-chlorid wurde bereits im Bd. E4, S. 383 beschrie-ben. 

Diphenyl-imidazolium-perchlorat addiert in Gegenwart von Kalium-tert.-butanolat Phe-nylisothiocyanat zum Betain I (49%), das durch Iodmethan zum 1,3-Diphenyl-2-[methylthio-phenylimino-methyl -imidazolium-iodid (II) methyliert wird696. 

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