NMR Study on the Possible Interactions Between Imidazolium Based Ionic Liquids and Extractants Widely Applied in Solvent Extraction and Separation of f-Ions

A detailed NMR study on the possible interactions between a series of imidazolium based ionic liquids (1-alkyl-3-methylimidazolium bis(trifluoromethylsulfonyl) amide, RmimTf(2)N, n = 4, 6, 8, 10), and compounds commonly applied in the solvent extraction and separation of 4f and 5f-ions as acidic chelating agents and neutral extractants is presented. The analytical techniques applied are H-1, C-13, F-19 and P-31 NMR spectra and NOESY experiments. Investigation of the types and strengths of the solvent-solute interactions is necessary for a better understanding of the chemical solubility, reactivity and selectivity, as ILs have a strong influence on the solvent extraction mechanism of metal ions. The goal of the scientific research is to gain insight on the role of ILs as a perspective efficient "green" medium in the solvent extraction processes. The experimental results show that no IL-ligand interactions occurred in chloroform solution independently on the length of the imidazolium alkyl chain or on the structure and acidity of the ligand. [GRAPHICS] .