L-n-butyl-3-methylimidazolium BMIM

The first successful hydrogenation reactions in ionic liquids were studied by the groups of de Souza [45] and Chauvin [46] in 1995. De Souza et al. investigated the Rh-catalyzed hydrogenation of cyclohexene in l-n-butyl-3-methylimidazolium ([BMIM]) tetrafluoroborate. Chauvin et al. dissolved the cationic Osborn complex [Rh(nbd)(PPh3)2][PFg] (nbd = norbornadiene) in ionic liquids with weakly coordinating anions (e.g., [PFg] , [BFJ , and [SbF ] ) and used the obtained ionic catalyst solutions for the biphasic hydrogenation of 1-pentene as seen in Scheme 5.2-7. 

Wasserscheid P, van Hal R, Bosmann A (2002) l-n-Butyl-3-methylimidazolium ([bmim]) octylsulfate-an even greener ionic liquid. Green Chem 4 400-404... 

Chapter 13 discusses the design and analysis of the microscopic features of binary solvent systems formed by room temperature ionic liquids (RTILs) with molecular solvents. For this purpose, protic ionic hquids (PILs), ethylammoiuum nitrate (FAN), and l-n-butyl-3-methylimidazolium (bmim)-based ILs and the molecular solvents such as acetonitrile, dimethyl sulfoxide, A,A-dimethylfonnamide, and protic (different alcohols) are selected. The study focuses on the identification of solvent mixtures of relevant solvating properties to propose them as new solvents. ... 

Figure 4.2-6 shows RDFs for the center of mass of [PFe] with the l-n-butyl-3-methylimidazolium [BMIM]" and [BMMIM]+ cations. The first sharp peak in g(r) for the [BMIM][Pp6] system is due to the anion localizing near the C2 carbon of the ring (the carbon between the two nitrogens). This behavior has been observed in nearly all simulations involving l-alkyl-3-meth)dimidazolium cations [11,12,14,15,... 

Wasserscheid, R, R. van Hal, and A. Bosmann. 2002. l-N-Butyl-3-Methylimidazolium ([Bmim]) Octylsulfate-an Even Greener Ionic Liquid. Green Chemistry 4 (4) 400-404. 

Table 2. Dynamic viscosities q of various l-n-butyl-3-methylimidazolium (BMIM) salts at 20 °C.

The advantage of the stoichiometric technique is that it is extremely simple. Care has to be taken to remove all gases dissolved in the IL sample initially, but this is easily accomplished because one does not have to worry about volatilization of the IL sample when the sample chamber is evacuated. The disadvantage of this technique is that it requires relatively large amounts of ILs to obtain accurate measurements for gases that are only sparingly soluble. At ambient temperature and pressure, for instance, 10 cm of l-n-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF6]) would take up only 0.2 cm of a gas with a Henry s law constant of... 

Bhargava, B.L., and Balasubramanian, S., Insights into the structure and dynamics of a room-temperature ionic liquid Ab initio molecular dynamics simulation studies of l-n-butyl-3-methylimidazolium hexafluorophosphate ([bmim][PFj]) and the [bmim][PFj]-C02 mixture, /. Phys. Chem. B, 111, 4477-4487, 2007. 

Alkylation at nitrogen has been achieved by treating indole or pyrrole with alkyl halides in ionic solutions of potassium carbonate in l-n-butyl-3-methylimidazolium tetrafluoroborate [bmim][BFJ <06TL2435>. Bis-protection of 3,3 -diiodo-2,2 -biindoles with Me, Boc, COjEt, or SOjPh has been described by Roy and Gribble <06SC3487>. 

Their abbreviations, for use in reaction schemes, are not universally defined, but amongst the common styles are, for example, l-n-butyl-3-methylimidazolium chloride = [BMIM][C1] or [bmim][Cl]. 

Published studies on the solubilities of gases in ionic liquids (ILs) have increased dramatically since 2000. These studies include common industrial gases such as CO2, reaction gases such as O2, as well as other gases of interest, such as light hydrocarbons. The number of ILs synthesized and analyzed has also increased, though the majority of these studies stiU focus on l-n-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF6]) as a benchmark IL. 

Recently, l-n-butyl-3-methylimidazolium and n-butylpyridinium salts [bmim]BF IL were used for catalytic media for the cycloaddition of carbon dioxide to propylene oxide reported by Blanchard L. A. et al. and Sergei V D. et al. [93, 94] (Scheme 7. la and b). 

The reduction of Pd(acac)2 (acac=acetylacetonate), dissolved in l-n-butyl-3-methylimidazolium hexafluorophosphat [BMIM][PF6] or l- -butyl-3-methylimidazolium tetrafluoroborate[BMIM][BF4] as ionic liquids, by molecular hydrogen (4 atm) at 75 °C affords stable, nanoscale Pd(0) particles with sizes of 4.9+0.8 ntn. In as much as 1,3-butadiene is at least four times more soluble in the l-n-butyl-3-methylimidazolium tetrafluoroborate than butenes, the selective partial hydrogenation could be performed by Pd(0) nanoparticles embedded in the ionic liquid (Umpierre et al., 2005). 

The reaction of NaBH4 with RuCls dissolved in l-n-butyl-3-methylimidazolium hexafluorophosphate [BM1M][PF6] and l- -butyl-3-methylimidazolium tetrafluoroborate [BMIM] [BF4] as ionic liquid is a simple and reproducible method for the synthesis of stable ruthenium oxide nanoparticles with a narrow size distribution within 2-3 nm. These nanoparticles showed high catalytic activity either in the solventless or liquid-liquid biphasic hydrogenation of olefins and arenes under mild reaction conditions. Nanometric ruthenium oxide confined in a zeolitic framework was recently reported as an efficient catalyst for alcohol oxidation under mild aerobic conditions. The nanofjarticles could be reused in solventless conditions up to 10 times in the hydrogenation of 1-hexene yielding a total turnover number for exposed Ru(0) atoms of 175,000 (Rossi et al., 2004 Rossi et al., 2004). 

EMIM = l-ethyl-3-methylunidazolium CF3SO3 = triflate anion ( ) BMIM = l-n-butyl-3-methylimidazolium < ) Oc = octyl Ts = H3CC6H4-SO2 (tosyl). 

Similarly, the cross-coupling reaction between imidazole and phenylboronic acid was performed with different ILs, and the results are grouped in Fig. 4. Among the ILs tested, hydrophilic [bmim][BF4] was found to be superior (95% yield) than that of hydrophobic [bmimHPFe] (80% yield), whereas the crosscoupling reaction was not successful in other molten salts such as n-tetrabuty-lammonium bromide (n-Bu4Br) and l-n-butyl-3-methylimidazolium bromide, [bmim][Br], under similar reactions conditions. These results clearly indicate that both the cation and anion play a signiflcant role in this cross-coupling reactions. 

Oxidation of 1-hexene by molecular oxygen has been conducted in 1-n-butyl-3- methylimidazolium hexafluorophosphate bmim I L. SC CO2, SC CO2/[bmim]PF6 mixed solvent, and in the absence of solvent. The selectivity to the desired product 2-hexanone is much higher when the reaction is carried out in the mixed solvent, and the catalysts is more stable in SC CO2/[bmim]PF6 mixed solvent than in SC CO2. 

ENIM]C1 AICI31 [BP] Cl AICI3 J [BMIM] = 1-butyl-3-methylimidazolium cation [EMIM] = l-ethyl-3-methylimidazolium cation [BP] = N-l-butylpyridinium cation... 

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