Extraction Behavior of Cu(II) Ion From Chloride Medium to the Hydrophobic Ionic Liquids Using 1,10-Phenanthroline

Abstract

The study of liquid-liquid extraction of Cu(II) ion was carried out by using a series of hydrophobic ionic liquids; 1-butyl-3-methylimidazolium hexafluorophosphate ([C₄mimPF₆]), 1-hexyl-3-methylimidazolium hexafluorophospahate ([C₆mimPF₆]), 1-butyl-3-methylimidazolium bistrifluoromethylsulfonyl imide ([C₄mimNTf₂]) and 1-hexyl-3-methylimidazolium bistrifluoromethylsulfonyl imide ([C₆mimNTf₂]) as extraction phase. Cu(II) prefer to extract into [C₄mimPF₆] which is the less hydrophobic of ionic liquids. The extraction behavior of Cu(II) ion depends on the type of counterion and the extraction of Cu(II) ion in ionic liquid system proceeds via similar mechanism with a molecular organic solvent. From these results, it was proposed that the extraction of Cu complexes from chloride medium proceeds through ion pair mechanism.

Keywords:

• 1,10-phenanthroline
• Cu(II) ion
• ion pair
• ionic liquid
• liquid-liquid extraction

ACKNOWLEDGEMENTS

The success of this research can be attributed to University Malaya Centre for Ionic Liquid (UMCIL), University of Malaya, and this research was financially supported by the TA010/2010 and PPP grants (PS334-2010A).

Notes

[Cu(II)] = 0.001 M, ratio of ionic liquid to aqueous phase 0.5:10, [phen] = 0.05 M, [HCl] = 0.01 M.