Novel class of functionalized ionic liquids with grafted CMPO-moieties for actinides and rare-earth elements recovery

Abstract

The general approach to a novel class of functionalized ionic liquids 4-6 bearing grafted diphenylcarbamoylmethylphosphine oxide complexing groups in the cation has been elaborated. The synthetic route comprises the preparation of the intermediate (diphenylphosphorylmethylcarbamoyl)propylimidazole 3, followed by sequential quaternization by alkyl halides (chlorides or bromides) and anionic exchange in the case of ionic liquids bearing the hexafluorophosphate anion. The structures of two ionic liquids were confirmed by X-ray analysis, revealing the strong intramolecular hydrogen bond formed by the acidic protons of the heterocycle and oxygen atom either of the P=O or C=O group, depending on the anion nature. In neutral media, these ionic ligands form complexes ML(2) with europium chloride or europium nitrate via an O,O-bidentate mode similar to known neutral CMPO compounds. The solid phase extractants prepared by immobilization of these FILs on solid matrixes possess sorption activity towards actinides and rare-earth elements in nitric acid solutions.

Probing of the local environment and calculation of J.O. parameters for Eu3+ CMPO functionalized pillararene complexes by time resolved fluorescence spectroscopy

“…Use of room temperature ionic liquid as solvent can also avoid the problem of third phase formation [31]. Reports are also available in the literature to demonstrate the high efficiency of even CMPO functionalized ionic liquid for extraction of actinides [32][33]. In our previous paper we have demonstrated the efficacy of DGA and phosphine oxides functionalized pillararene ligands in extraction of trivalent actinides and lanthanides as well as transition metals [34][35][36].…”

Recovery of scandium(iii) from diluted aqueous solutions by a supported ionic liquid phase (SILP)

“…This further makes SILPs suitable not only for applications in catalysis, [29][30][31][32] but also for metal ions adsorption and preconcentration. 28,[33][34][35] SILPs are classied in two groups. The rst group consists of the classic SILP materials where the IL is impregnated on a porous support material.…”

Using Crystal Structures of Ionic Compounds to Explore Complexation and Extraction of Rare Earth Elements in Ionic Liquids

“…These range from largely noncoordinating ILs, such as dialkylimidazolium salts of perfluoroanions [11] or long-chain alkylammonium and phosphonium halides [12] and nitrates [13], to those which are designed to actively coordinate the metal ion [14][15][16]. On the other hand, ILs (and related systems such as deep eutectic solvents [17]) have also been designed which can dissolve highly insoluble metal phases (such as oxides) [18].…”