The effect of hydrophobic picrate on the extraction and separation of lanthanides(III) with carbamoylmethylene phosphine oxide

Role of hydrophobic counteranions in the ion pair extraction of lanthanides(iii) with an electrically neutral extractant

“…5 was used for Eu(III). 3,9 The activity coefficients of NO 3 À were calculated on the basis of the Debye-Hu ¨ckel theoretical equation using 3 A ˚as an ion size parameter. 10 From the slope of the plot in Fig.…”

“…The '' dehydration '' was previously found in a lanthanide(III)-complex cation paired with three picrate ions in benzene, by measuring the amount of coextracted water with the ion pair. 3 The ion pair of the metalcomplex cation with picrate ions was, indeed, much less hydrated than that of the same cation with NO 3 À ions. This can be explained from the lack of '' conserving effects '' on the hydration shell of the metal ion paired with picrate ions.…”

“…Here, a hydrophobic and weakly coordinatebonding anion is very useful for the enhancement of the extractability from aqueous solutions of low ionic strength. 2,3 Furthermore, such an anion has the great advantage of improving the selectivity for metal ions, in addition to enhancing the extractability for them: 3 In contrast, a synergism using two coordinate bonding extractants generally decreases the selectivity. 4 In the present study, tetrakis [3,5-bis(trifluoromethyl)phenyl] borate (TFPB À ) is employed as a hydrophobic anion.…”

Importance of counter-ions in alkali and alkaline-earth cation extraction by 18-crown-6: molecular dynamics studies at the water/sc-CO2interface

“…49 Aqueous lanthanide(III) cation extraction to benzene by CMPO (carbamoylphosphine oxide) is greatly enhanced by adding small amounts of Pic À anions. 50 To our knowledge, there are no systematic investigations on the anion effect on cation extraction to sc-CO 2 , but the work of Inamoto and co-workers 7 clearly demonstrates the enhancement of K + extraction by 18C6 and its derivatives to CO 2 , via the formation of 1 : 1 : 1 complexes of K + &18C6,PFO À type. This is consistent with our simulation results on this system, in which some complexes are extracted to CO 2 , while with Pic À as counter-ions, no such extraction proceeds (see also ref.…”

Solvent extraction of intra-lanthanides using a mixture of TBP and TODGA in ionic liquid

“…The similar cooperative effect of neutral organic ligand and hydrophobic anions was previously observed for the extraction of Ln(III) from nitric acid solutions. 48,49 Therefore, in TODGA/TBP/IL system, hydrophobic Tf2Nanions probably play a role of counter ions resulting in more hydrophobic metal species compared with that with nitrate anions. Moreover, not only solvation or ion pairing mechanism but also ion-exchange could take place in the system with ionic liquid as diluent due to its ionic nature, in particular at low aqueous acidity.…”