L-butyl-3-methyl imidazolium chloride

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... 

The reaction does not occur obviously in three commonly used ILs l-butyl-3-methyl-imidazolium chloride ([BMIm]Cl), 1-butyl-3-methyl-imidazolium tetra-fluoroborate ([BMIm]BF4), l-butyl-3-methyl-imidazolium hexafluorophosphate ([BMIm]PF6). Only 3 % yield can be obtained in water, indicating PEG is the best solvent for the oxidation of secondary alcohols when using Co(II)/ZnO as catalyst. This is because PEG can form Co(II) complex (Co(II)L), which can activate 02 molecule and thereby promote the oxidation of organic compounds (Scheme 3.3) [26]. 

Potentiostat, (typically, Echochemie, Autolab PGSTAT), Schlenk tube x 2, aluminum sheet, mild steel rods, P400 sand paper, anhydrous AICI3, l-butyl-3-methyl imidazolium chloride ([BMIM]C1), toluene, acetone, dichloromethane, HC1, HNO3, H3PO4, acetic acid, isopropanol. 

In another approach, the dehydration has been conducted in ionic liquids (l-alkyl-3-methylimidazolium chloride) under acid or metal chloride catalysis yielding HMF up to more than 80% nearly without any formation of by-products like levulinic acid [32], When using chromium(II) chloride as catalyst even D-glucose could be used as feedstock since this catalyst is effective for the in situ isomerization of o-glucose to o-fructose before dehydration takes place to produce HMF in 70% yield. The catalyst system N-heterocyclic carbene/CrCU in l-butyl-3-methyl imidazolium chloride has been developed for the selective conversion of D-fructose (96% yield) and o-glucose (81% yield) [33]. 

Figure 4.7 CVs for the oxidation of AA (1.0 mM] at bare [curve a] and l-butyl-3-methyl imidazolium chloride [[BMIM][Cl]]-modified [curve b] GC electrodes in 0.10 M phosphate buffer. Curves a and b represent CVs obtained at the above electrodes in the same solution containing no AA. Scan rate, 100 mV s" Reprinted with permission from Ref. [48]. Copyright 2005 American Chemical Society.

Current investigations are aimed at providing polymers derived from renewable resources but with electroactive properties. For example, an ionic liquid (l-butyl-3-methyl imidazolium chloride BMIM-Cl) was used as a plasticizer in starch, zein and their blends, and compared to glycerol, as a classical plasticizer of starch [96]. 

Xie, L. L., Favre-Reguillon, A., Wang, X. X., Fu, X., Pellet-Rostaing, E., Toussaint, G., Geantet, C., Vrinat, M. Lemaire, M. (2008). Selective Extraction of Neutral Nitrogen Compounds Found in Diesel Feed by l-Butyl-3-Methyl-Imidazolium Chloride. Green Chemistry, Vol. 10, No. 5, pp. 524-531, ISSN 1463-9262... 

Geantet, G. Vrinat, M. Lemaire, M. (2008). Selective extraction of neutral nitrogen compounds found in diesel feed by l-butyl-3-methyl-imidazolium chloride. Green Chem., 10, 524-531, ISSN 1463-9270. 

Recently, the air- and water-stable combinations of l-n-butyl-3-methyl-imidazolium chloride with sodium tetrafluoroborate or sodium hexafluoro-phosphate have been prepared. The rhodium complexes [RhCl(PPh3)3] and [Rh(COD)2](BF4) are completely soluble in these ionic liquids and catalyze the hydrogenation of cyclohexene in a typical two-phase reaction with numbers of turnovers of up to 6000 (131). 

Fig. 4.1 Simplified electrochemical windows of 1-butyl-pyridinium chloride and l-ethyl-3-methyl-imidazolium chloride.

As discussed above, the HOR and the closely related hydrogen evolution reaction (HER the reverse of Eq. 17.2) are of fundamental and applied interest to electrochemists and each has been studied in RTILs [33, 38, 60-62]. Compton and co-workers reported that the appearance and position of the HER peak during HOR/HER electrochemistry in RTILs depends on the stability of the protonated anion (the RTIL anions accommodate the protons generated during the HOR) and on the equilibrium position of the protonation reaction [60]. For example, the HOR is quasireversible in [N(Tf2)] -based RTILs while the reduction process is not observed at all in 1-hexyl-3-methyl imidazolium chloride and l-butyl-3-methyl imidazolium nitrate, indicating that the electrochemically generated protons react with the anions of the RTIL [60, 61]. 

Phenothiazines contain positively charged amine groups in a mobile phase at low pH. Therefore, they are retained in the presence of ionic liquids through the combination of electrostatic interactions and hydrophobic effects. The effects of the concentration and the type of ionic liquid on the retention of the analyfes, peak symmetry, and efficiency were examined. The following trends increase the retention factor of the analytes and improve system efficiency 1-but-yl-3-methylimidazolium hexafluorophosphate > l-ethyl-3-methyl-imidazolium hexafluorophosphate > l-butyl-3-methylimidazolium chloride. 

Figure 45 Structure of l-(l-butyl) pyridinium chloride (BPC) and l-methyl-3 ethyl-imidazolium chloride (MEIC).

Endres F, Freyland W (1998) Electrochemical scanning tunneling microscopy investigation of HOPG and silver electrodeposition on HOPG from the acid room-temperature molten salt aluminum chloride l-methyl-3-butyl-imidazolium chloride. J Phys Chem B 102(50) 10229-10233... 

In one of the first studies, Stepnowski Zaleska compared the effectiveness of three methods UV photodegradation, UV photolysis of hydrogen peroxide, and photocatalysis on UV-irradiated Ti02. For these investigations imidazolium ILs with different alkyl chain length were chosen (1-butyl-, l-hexyl-3-methylimidazolium, l-methyl-3-octylimidazolium, l-ethyl-3-ethylimidazolium chloride or tetrafluoroborate, methyl imidazole as reference). The stability of these compoxmds with respect to all the photodegradation methods used... 

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