From extraction experiments and c-activity measurements, the exchange extraction constants corresponding to the general equilibrium M(aq) ? Sr(nb) ¢ M(nb) ? Sr(aq) taking part in the two-phase water– nitrobenzene system (M = Mg, Ca, Ba, Cu, Zn, Cd, Pb, UO2þ 2 , Mn , Fe, Co, Ni; aq = aqueous phase, nb = nitrobenzene phase) were evaluated. Furthermore, the individual extraction constants of the M cations in the mentioned two-phase system were calculated; they were found to increase in the following cation order: UO2þ 2 \ Zn , Ni \ Cu, Cd \ Co \ Mg \ Ca \ Mn, Fe \ Sr \ Pb \ Ba.

Individual extraction constants of some divalent metal cations in the two-phase water–nitrobenzene system

From extraction experiments in the two-phase water/nitrobenzene system and γ-activity measurements, we determined the stability constant of the dibenzo-30-crown-10·Tl+ complex species dissolved in nitrobenzene saturated with water. By using quantum–mechanical calculations, we then predicted the most probable structure of this complex species.Graphical abstract.

Complexation of the thallium cation with dibenzo-30-crown-10: extraction and theoretical study

Extraction of microamounts of europium and americium by a nitrobenzene solution of hydrogen dicarbollylcobaltate (H+B−) in the presence of tetraisopropyl methylene diphosphonate [T(iPr)MDP, L] has been investigated. The equilibrium data have been explained assuming that the complexes HL+, HL2+, ML23+, ML33+ and ML43+ (M3+ = Eu3+, Am3+) are extracted into the organic phase. The values of extraction and stability constants of the species in nitrobenzene saturated with water have been determined. It was found that the stability constants of the corresponding complexes EuLn3+ and AmLn3+, where n = 2, 3, 4 and L is T(iPr)MDP, in water-saturated nitrobenzene are comparable.

Extraction of calcium and strontium into nitrobenzene by using a synergistic mixture of hydrogen dicarbollylcobaltate and tetraisopropyl methylene diphosphonate

Extraction of microamounts of europium and americium by a nitrobenzene solution of hydrogen dicarbollylcobaltate (H+B−) in the presence of bis(diphenylphosphino)methane dioxide (DPPMDO, L) has been investigated. The equilibrium data have been explained assuming that the species $$ {\text{HL}}^{ + } $$
 , $$ {\text{HL}}_{2}^{ + } $$
 , $$ {\text{ML}}_{2}^{3 + } $$
 , $$ {\text{ML}}_{3}^{3 + } $$
 and $$ {\text{ML}}_{4}^{3 + } $$
 (M3+ = Eu3+, Am3+) are extracted into the organic phase. The values of extraction and stability constants of the species in nitrobenzene saturated with water have been determined. It was found that the stability constants of the corresponding complexes $$ {\text{EuL}}_{n}^{3 + } $$
 and $$ {\text{AmL}}_{n}^{3 + } $$
 , where n = 2, 3 and L is DPPMDO, in water–saturated nitrobenzene are comparable, whereas in this medium the stability of the cationic species $$ {\text{AmL}}_{4}^{3 + } $$
 (L = DPPMDO) is somewhat higher than that of $$ {\text{EuL}}_{4}^{3 + } $$
 with the same ligand L.

Synergistic extraction of europium and americium into nitrobenzene by using hydrogen dicarbollylcobaltate and 1,2-(diphenylphosphino)ethane dioxide

From extraction experiments and c-activity measurements, the exchange extraction constants corre- sponding to the general equilibrium M 2þ aq ðÞ þSr 2þ org ðÞ , M 2þ org ðÞ þSr 2þ aq ðÞ taking place in the two-phase water-phenyltrifluoromethyl sulfone (abbrev. FS 13) system (M 2? = Mg 2? ,C a 2? ,B a 2? ,C u 2? ,Z n 2? ,C d 2? ,P b 2? , UO 2þ 2 ,M n 2? ,F e 2? ,C o 2? ,N i 2? ;a q= aqueous phase, org = FS 13 phase) were evaluated. Furthermore, the indi- vidual extraction constants of the M 2? cations in this two- phase system were calculated; they were found to increase in the series of Mg 2? ,UO 2þ 2 \ Ca

Individual extraction constants of some univalent cations in the two-phase water–phenyltrifluoromethyl sulfone system

Extraction of microamounts of europium and americium by a nitrobenzene solution of hydrogen dicarbollylcobaltate (H + B - ) in the presence of N, N, N', N'- tetraisobutyl - 2, 6 - dipicolinamide [T(iBu)DPA, L] has been investigated. The equilibrium data have been explained assuming that the cations HL + , HL + 2 , ML 3 2 + and ML 3 3 + (M 3+ = Eu 3+ , Am 3+ ) are extracted into the organic phase. The values of extraction and stability constants of the species in nitrobenzene saturated with water have been determined.

Extractive Properties of Synergistic Mixture of Hydrogen Dicarbollylcobaltate and N, N, N', N' - Tetraisobutyl - 2, 6 - Dipicolinamide in the Water - Nitrobenzene System with Regard to Eu3+ and Am3+

Igor V. Srnirnov

Papers

Extractive Properties of Synergistic Mixture of Hydrogen Dicarbollylcobaltate and N, N, N', N' - Tetraisobutyl - 2, 6 - Dipicolinamide in the Water - Nitrobenzene System with Regard to Eu3+ and Am3+