Cations alkylimidazolium

Hagiwara, R., Ito, Y. Room temperature ionic liquids of alkylimidazolium cations and fluoroanions, J. Fluorine Chem., 105(2), 2000, 221-227 Welton, T. Room-temperature Ionic Liquids. Solvents for Synthesis and Catalysis, Chem. Rev., 1999, 99, 2071-2084 ... 

IL with alkylimidazolium cation-fluorinated anion combination IL with non-imidazolium cation-fluorinated anion combination... 

IL with Alkylimidazolium Cation-Fluorinated Anion Combination... 

Hagiwara R, Ito Y (2000) Room temperature ionic liqttids of alkylimidazolium cations and ftuoroanions. J Fluor Chem 105 221—227... 

Figure 1. Representative cations used in PILs, including (a) primary, secondary, or tertiary ammonium cations (where Ri, R2, and/or R3 can be hydrogen atoms), (b) 1-alkylimidazolium cations, (c) l-alkyl-2-alkylimidazolium cations, (d) caprolactam, and (e) 1,1,3,3-tetramethylguanidinine.

The alkylammonium nitrate salts and salts containing the l-alkyl-2-alkylimidazolium cation with chloride or bromide anions were mostly molten salts, in that their melting points were >100 °C. In contrast, the PILs that contained alkylammonium cations with small carboxylic acids and most of the salts with an imidazolium cation were predominately RT-PILs, or had low melting points. 

The IR spectra of the as-prepared nanoparticles and nanocubes are shown in Fig. 9.22. The peaks at 2856, 2928, and 2962 cm" were assigned to the antisymmetric stretches, symmetric methylene stretches (Vas(CH2), Vs(CH2)), and antisymmetric methyl stretches (Vas (CH3)) of l-methyl-3-octylimidazolium cations. The peak at 1465 cm" was assigned to ring in-plane asymmetry stretches and CH3 (N) stretches. These results identified the presence of alkylimidazolium cations on the surfaces of the amorphous nanoparticles and the nanocubes. 

To determine the lipophilicity of ionic liquids, different stationary phases have been tested such as Supelcosil LC-8-DB, Symmetiy C8, ACE 5 C18, Symmetry C18 with aqueous acetonitrile buffered at pH 3.55 mobile phases (Molikova et al., 2010a). In this study the log few parameters were correlated with logP calculated by the HyprerChem software. Good correlations were found for homologous alkylimidazolium cations analyzed by RP HPLC especially in the case of the Symmetry C8 column (R2 = 0.9966). 

Scheme 22.28 Pyrrolidine derivatives tagged to alkylimidazolium cations and their use as organocatalysts in asymmetric Michael reactions of carbonyl compounds with a-nitroalkenes.

Fig. 2. Structure and the viscosity of several alkylimidazolium cations based RTILs (Kongef...

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