L-Octyl-3-methylimidazolium hexafluorophosphate

Fig. 6.21 Linear sweep voltammograms recorded at modified glassy carbon electrodes in 5.0 pM NO2, 0.1 M phosphate buffer solution 0.1 Vs potential scan rate. Different electrode coatings have been considered a) carbon nanotubes (CNTs), b) CNTs-Chit, (c) OMIMPF6-CNT-Chit d) (OMIMPFg-CNT) gel, e) (OMIMPFg-CNT) gel-Chit (Chit chitosan OMIMPFe l-octyl-3-methylimidazolium hexafluorophosphate) (Adapted with permission of the authors. Reproduced from Ref. [221] with the permission of Wiley)...

Two ionic liquids, i.e., l-butyl-3-methylimidazolium hexafluoro-phosphate, cf. Figure 1.5, and l-octyl-3-methylimidazolium hexa-fluorophosphate have been compared as extraction solvents. It was foimd that l-octyl-3-methylimidazolium hexafluorophosphate showed higher recoveries for each analyte. 

BMIm-PF l-buthyl-3-methylimidazolium hexafluorophosphate HMIm-PFg l-hexyl-3-methylimidazolium hexafluorophosphate OMIm-PFg l-octyl-3-methylimidazolium hexafluorophosphate... 

Lohithakshan, K.V. Aggarwal, S.K (2008) Solvent extraction studies of Pu(IV) with CMPO in l-octyl-3-methylimidazolium hexafluorophosphate (CsmimPF6) room temperature ionic liquid (RTIL). Radiochim. Acta 96 93-97. 

Lipases from C. antarctica and P. cepacia showed higher enantioselectivity in the two ionic liquids l-ethyl-3-methylimidazolium tetrafluoroborate and l-butyl-3-methylimidazolium hexafluoroborate than in THE and toluene, in the kinetic resolution of several secondary alcohols [49]. Similarly, with lipases from Pseudomonas species and Alcaligenes species, increased enantioselectivity was observed in the resolution of 1 -phenylethanol in several ionic liquids as compared to methyl tert-butyl ether [50]. Another study has demonstrated that lipase from Candida rugosa is at least 100% more selective in l-butyl-3-methylimidazolium hexafluoroborate and l-octyl-3-nonylimidazolium hexafluorophosphate than in n-hexane, in the resolution of racemic 2-chloro-propanoic acid [51]. 

The fluorescent probe 4-aminophthalimide (63) as well as its /V,/V-diethyl homomorph (89) were used by Samanta and coworkers148 149 to study the polarity and fluorescence dynamics in l-alkyl-3-methylimidazolium salts. The alkyl groups were variously ethyl, butyl and octyl and the anions were nitrate, tetrafluoroborate, hexafluorophosphate and bis(triflyl)imide. Similar conclusions were reached concerning the effects of alkyl chain length and anion as those obtained by Carmichael and Seddon142 using Nile Red. The solvation dynamics were found to depend on the viscosity of the media. Further use of 63 in l-butyl-3-methylimidazolium hexafluorophosphate was reported by Ingram and... 

ILs, mainly quaternary ammonium salts with hydrophobic anions, e.g., l-n-octyl-3-methylimidazolium hexafluorophosphate and tetrafluoroborate, are nonvolatile solvents that can be also applied in extraction. The selection of anions decides the IL hy-drophobicity, the formation of a two-phase system with water, the solubility of n.s in water and of water in ILs, and the IL s hydroscopic properties. Up to now, the hydrophobic ILs that form separated phases with water contain potentially dangerous anions, such as PFe and BF4T, which may decompose and produce fluoride ions. ILs are more viscous than typical solvents and may interfere with the transfer of ionic species. New applications for small-scale separations may emerge in the future. 

F) Water/l-octyl-3-methylimidazolium chloride (amphiphihc)/l-butyl-3-methyhmidazolium hexafluorophosphate (nonpolar phase) ... 

More data for liquid-ionic liquid partition coefficients of different organic compounds were described for the biphasic systems containing alkyl ammonioum ionic liquids ethylammonium nitrate, n-propylammonium nitrate, or di-n -propylammonium thiocyanate and hexane, toluene, octan-l-ol, or dichloromethane (Poole, 2007 Shetty et al., 1987 Shetty et al., 1990) or aqua biphasic systems formed by l-butylammonium-3-methylimidazolium hexafluorophosphate and water or heptane ( Berthod Carda-Broch, 2003 Khachatryn et al., 2005 Carda-Broch et al., 2003) or the l-octyl-3-methylimidazolium hexa-fluorophosphate-water biphasic system ( Liu et al., 2004). 

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