Solvent extraction of lead using a nitrobenzene solution of strontium dicarbollylcobaltate in the presence of polyethylene glycol PEG 400

Summary From extraction experiments and γ-activity measurements, the extraction constant corresponding to the equilibrium Pb²⁺(aq)+SrL²⁺ (nb)↔PbL²⁺ (nb)+Sr²⁺ (aq) taking place in the two-phase water-nitrobenzene system (L=PEG 400; aq = aqueous phase, nb = nitrobenzene phase) was evaluated as logK_ex(Pb²⁺, SrL²⁺)=2.0±0.1. Further, the stability constant of the PEG 400 - lead complex in nitrobenzene saturated with water was calculated for a temperature of 25 °C: log β_nb(PbL²⁺)=12.9±0.1.     

Extraction of lithium with nitrobenzene solution of strontium bis-1,2-dicarbollylcobaltate in the presence of 15-crown-5

From extraction experiments and γ-activity measurements, the extraction constant corresponding to the equilibrium 2Li⁺(aq)+SrL₂ ²⁺(nb) 2LiL⁺(nb)+Sr²⁺(aq) taking place in the two-phase water-nitrobenzene system (L=15-crown-5; aq=aqueous phase, nb=nitrobenzene phase) was evaluated as logK _ex (2Li⁺;SrL₂ ²⁺)=−3.7. Further, the stability constant of the 15-crown-5—lithium complex in nitrobenzene saturated with water was calculated: log β_nh(LiL⁺)=7.0.     

Stability of the valinomycin - strontium complex in water saturated nitrobenzene

Summary From extraction experiments and<span style='font-size:12.0pt;font-family:Symbol; mso-bidi-font-family:Symbol'>g-activity measurements, the extraction constant corresponding to the equilibrium Ba²⁺(aq)+SrL²⁺(nb)?BaL²⁺(nb)+Sr²⁺(aq) taking place in the two-phase water-nitrobenzene system (L= valinomycin; aq= aqueous phase,</o:p>nb= nitrobenzene phase) was evaluated as logK_ex(Ba²⁺, SrL²⁺)=1.3. Furthermore, the stability constant of the valinomycin-strontium complex in nitrobenzene saturated with water was calculated for a temperature of 25 °C: logb_nb(SrL²⁺)=5.4.     

Stability of Ba2+-15-crown-5 complex in water saturated nitrobenzene

From extraction experiments and γ-activity measurements, the extraction constant of the Ba²⁺ (aq)+SrL₂/²⁺(nb)⇆⇆BaL₂/²⁺ (nb)+Sr²⁺(aq) equilibrium taking place in a two-phase water-nitrobenzene system (L=15-crown-5; aq-aqueous phase, nb=nitrobenzene phase) was evaluated as logK _ex(Ba²⁺,SrL₂/²⁺)=1.8. Further, the stability constant of the BaL₂/²⁺ complex in water saturated nitrobenzene was calculated to be log β_nh(BaL₂ ²⁺)=16.5.     

Extraction of Ba<Superscript>2+</Superscript>, Pb<Superscript>2+</Superscript> and Cd<Superscript>2+</Superscript> into nitrobenzene by using strontium dicarbollylcobaltate in the presence of tetramethyl <Emphasis Type="Italic">p-tert</Emphasis>-butylcalix[4]arene tetraketone

From extraction experiments and γ-activity measurements, the exchange extraction constants corresponding to the general equilibrium M²⁺(aq)+SrL²⁺(nb)⇔ML²⁺(nb)+Sr²⁺(aq) taking place in the two-phase water-nitrobenzene system (M²⁺ = Ba²⁺, Pb²⁺, Cd²⁺; L = tetramethyl p-tert-butylcalix[4]arene tetraketone; aq = aqueous phase, nb = nitrobenzene phase) were evaluated. Moreover, the stability constants of the ML²⁺ complexes in water saturated nitrobenzene were calculated; they were found to increase in the order Ba²⁺<Cd²⁺<Pb²⁺.     

Extraction of lead from water into nitrobenzene by using strontium dicarbollylcobaltate in the presence of benzo-15-crown-5

Summary From extraction experiments andg-activity measurements, the extraction constant corresponding to the equilibrium Pb²⁺(aq)+SrL(nb)?PbL(nb)+Sr²⁺(aq)taking place in the two-phase water-nitrobenzene system (L = benzo-15-crown-5; aq = aqueous phase, nb = nitrobenzene phase) was evaluated aslog K_ex(Pb²⁺,SrL)=0.1±0.1. Further, the stability constant of the benzo-15-crown-5-lead complex in nitrobenzene saturated with water was calculated for a temperature of25 °C:log b_nb(PbL)=13.2±0.1.     

Extraction of Pb2+ with sodium dicarbollylcobaltate in the presence of 15-crown-5

From extraction experiments with ²² Na as a tracer, the exchange extraction constant corresponding to the equilibrium Pb²⁺ (aq)+2 NaL⁺ (nb)PbL₂ ²⁺ (nb)+2 Na⁺ (aq) in the two-phase water-nitrobenzene system (L = 15-crown-5; aq = aqueous phase, nb = nitrobenzene phase) was evaluated as log K_ex (Pb²⁺ , 2NaL⁺ ) = 4.7±0.1. Moreover, the stability constant of the complex PbL₂ ²⁺ in nitrobenzene saturated with water was calculated for a temperature of 25 °C as log _nb (PbL₂ ²⁺ ) = 17.9±0.1.     

Distribution of Strontium in the System Water — Ca(NO3)2 — Nitrobenzene — Strontium Dicarbollylcobaltate — 18-crown-6

From several strontium distribution experiments with ⁸⁵Sr tracer, the extraction constant corresponding to the equilibrium Ca²⁺(aq)+SrL²⁺(nb) CaL²⁺(nb)+Sr²⁺ (aq) in the two-phase water-nitrobenzene system (L = 18-crown-6; aq = aqueous phase, nb = nitrobenzene phase) was tentatively evaluated as log K _ex (Ca²⁺,SrL²⁺) = –1.9±0.1. Furthermore, the stability constant of the calcium — 18-crown-6 complex in nitrobenzene saturated with water was calculated for a temperature of 25 °C: log _nb(Cal²⁺) = 10.1±0.1.     

Solvent extraction of magnesium, zinc and manganese into nitrobenzene by using strontium dicarbollylcobaltate in the presence of valinomycin

From extraction experiments and γ-activity measurements, the exchange extraction constants corresponding to the general equilibrium M²⁺(aq)+SrL²⁺(nb)⇔ML²⁺(nb)+Sr²⁺(aq) taking place in the two-phase water-nitrobenzene system (M²⁺ = Mg²⁺, Zn²⁺, Mn²⁺; L = valinomycin; aq = aqueous phase, nb = nitrobenzene phase) were evaluated. Further, the stability constants of the ML²⁺ complexes in water saturated nitrobenzene were calculated. They were found to increase in the order of Mg²⁺<Mn²⁺<Zn²⁺.     

Stability of the 15-crown-5-sodium complex in water saturated nitrobenzene

From extraction experiments with²²Na as a tracer, the extraction constant corresponding to the equilibrium Ba²⁺(aq)+2NaL⁺(nb)⇄ ⇄BaL₂ ²⁺(nb)+2Na⁺(aq) taking place in the two-phase water-nitrobenzene system (L=15-crown-5; aq=aqueous phase, nb=nitrobenzene phase) was evaluated as logK _ex (Ba²⁺,2NaL⁺)=3.3±0.1. Further, the stability constant of the complex BaL₂ ²⁺ in nitrobenzene saturated with water was calculated: log β_nh(BaL ₂ ²⁺ )=16.4±0.1.     

Stability of the valinomycin - lithium complex in nitrobenzene saturated with water

Summary From extraction experiments and γ-activity measurements, the extraction constant corresponding to the equilibrium Li⁺(aq)+NaL⁺(nb) ↔LiL⁺(nb)+Na⁺(aq) taking place in the two-phase water-nitrobenzene system (L = valinomycin; aq = aqueous phase, nb = nitrobenzene phase) was evaluated as logK_ex(Li⁺,NaL⁺)=-1.1. Further, the stability constant of the valinomycin-lithium complex species in nitrobenzene saturated with water was calculated: logβ_nb(LiL⁺)=6.3.     

Solvent extraction of barium picrate by p-tert-butylcalix[4]arene-tetrakis (N,N-diethylacetamide)

Summary From extraction experiments andg-activity measurements, the extraction constant of the Ba²⁺(aq)+2A^-(aq)+L(nb)?BaL²⁺(nb)+2A^-(nb) equilibrium in the two-phase water-nitrobenzene system (L = p-tert-butylcalix[4]arene-tetrakis (N,N-diethylacetamide); aq = aqueous phase, nb = nitrobenzene phase) was evaluated as logK_ex(BaL²⁺,2A^-)=6.5±0.1. Furthermore, the stability constant of the p-tert-butylcalix[4]arene-tetrakis (N,N-diethylacetamide)̵barium complex in nitrobenzene saturated with water was calculated for at 25 °C as logb_nb(BaL²⁺)=15.4±0.1.     

Stability of complex of Na+ with 18-crown-6 in nitrobenzene saturated with water

From extraction experiments and γ-activity measurements, the extraction constant corresponding to the equilibrium Na⁺(aq)+HL⁺(nb)⇆NaL⁺(nb)+H⁺(aq) taking place in the two-phase water-nitrobenzene system (L=18-crown-6; aq=aqueous phase, nb=nitrobenzene phase) was evaluated as logK _ex (Na⁺,HL⁺)=0.1. Further, the stability constant of the 18-crown-6-sodium complex in nitrobenzene saturated with water was calculated: logβ _nh(NaL⁺)=8.0.     

Solvent extraction of sodium from water into nitrobenzene by using strontium dicarbollylcobaltate in the presence of benzo-15-crown-5

Summary From extraction experiments andg-activity measurements, the extraction constant corresponding to the 2Na⁺(aq)+SrL(nb)?2NaL⁺(nb)+Sr²⁺(aq) equilibrium taking place in the two-phase water-nitrobenzene system (L=benzo-15-crown-5; aq=aqueous phase, nb=nitrobenzene phase) was evaluated as log K_ex(2Na⁺,SrL)=1.0±0.1. Further, the stability constant of the benzo-15-crown-5-sodium complex in nitrobenzene saturated with water was calculated for a temperature of 25 °C: log b_nb(NaL⁺)=7.8±0.1.     

Solvent extraction of strontium picrate from water into nitrobenzene in the presence of benzo-15-crown-5

From extraction experiments with 85Sr as a tracer, the extraction constant corresponding to the equilibrium Sr²⁺(aq) + 2A^- (aq) + 2L (nb) Û SrL₂ ^,2+ (nb) 2A^- (nb) in the two-phase water-nitrobenzene system (A^- = picrate, L = benzo-15-crown-5; aq = aqueous phase, nb = nitrobenzene phase) was evaluated as log K _ex     

Stability of the ammonium-p-tert-butylcalix[4]arene-tetrakis (N,N-diethylacetamide) complex in nitrobenzene saturated with water

Summary From extraction experiments andg-activity measurements, the extraction constant corresponding to the equilibrium NH(aq)+NaL⁺(nb)?NH₄L⁺(nb)+Na⁺(aq) taking place in the two-phase water-nitrobenzene system (L = p-tert-butylcalix[4]arene-tetrakis (N,N-diethylacetamide); aq = aqueous phase, nb = nitrobenzene phase) was evaluated as logK_ex(NH,NaL⁺)=-1.8. Further, the stability constant of the p-tert-butylcalix[4]arene-tetrakis (N,N-diethylacetamide)-ammonium complex in nitrobenzene saturated with water was calculated for a temperature of 25 °C: logb_nb(NH₄L⁺)=6.7.     

Extraction of silver from water into nitrobenzene using sodium dicarbollylcobaltate in the presence of valinomycin

Summary From extraction experiments andg-activity measurements, the extraction constant corresponding to the Ag⁺(aq) + NaL⁺(nb)?AgL⁺(nb) + Na⁺(aq) equilibrium in the two-phase water-nitrobenzene system (L=valinomycin; aq=aqueous phase, nb=nitrobenzene phase) was evaluated as log K_ex(Ag⁺,NaL⁺)=-0.6±0.1. The stability constant of the valinomycin-silver complex in nitrobenzene saturated with water was calculated: log b_nb(AgL⁺)=4.6±0.1. The stability constants of complexes of some univalent cations with valinomycin were summarized and discussed.     

Extraction of barium picrate into nitrobenzene in the presence of benzo-15-crown-5

From extraction experiments with ¹³³Ba as a tracer, the extraction constant corresponding to the equilibrium Ba²⁺(aq) + 2A^-(aq) + 2L(nb) BaL₂ ²⁺(nb) + 2A^-(nb) in the two-phase water-nitrobenzene system (A^- = picrate, L = benzo-15-crown-5; aq = aqueous phase, nb = nitrobenzene phase) was evaluated as log K _ex (BaL₂ ²⁺, 2A^-) = 5.7. Furthermore, the stability constant of the benzo-15-crown-5 - barium complex in nitrobenzene saturated with water was calculated: log b_nb (BaL₂ ²⁺) = 14.6.     

Experimental Evidence for a Valinomycin – Proton Complex

Summary. From extraction experiments and γ-activity measurements, the extraction constant corresponding to the equilibrium H⁺ (aq) + NaL⁺ (nb) = HL⁺ (nb) + Na⁺ (aq) taking place in the two-phase water-nitrobenzene system (L = valinomycin, aq = aqueous phase, nb = nitrobenzene phase) was evaluated as log K_ex (H⁺, NaL⁺) = −1.1 ± 0.1. Further, the stability constant of the valinomycin-proton complex in nitrobenzene saturated with water was calculated as log β_nb(HL⁺) = 5.3 ± 0.1. Finally, the stability constants of complexes of some univalent cations with valinomycin were summarized and discussed.     

Extraction of H+, NH4 +, Ag+ and Tl+ into nitrobenzene by using sodium dicarbollylcobaltate in the presence of tetramethyl p-tert-butylcalix[4]arene tetraketone

From extraction experiments and γ-activity measurements, the exchange extraction constants corresponding to the general equilibrium M⁺(aq)+NaL⁺(nb)⇔ML⁺(nb)+Na⁺(aq) taking place in the two-phase water-nitrobenzene system (M⁺ = H⁺, NH₄⁺, Ag⁺, Tl⁺; L = tetramethyl p-tert-butylcalix[4]arene tetraketone; aq = aqueous phase, nb = nitrobenzene phase) were evaluated. Moreover, the stability constants of the ML⁺ complexes in water saturated nitrobenzene were calculated; they were found to increase in the order Tl⁺<NH₄⁺<Ag⁺ <H⁺ <Na⁺.