On the complexation of some univalent cations with 1,3-alternate-25,27-bis(1-octyloxy)calix[4]arene-crown-6 in nitrobenzene saturated with water

From extraction experiments and γ-activity measurements, the exchange extraction constants corresponding to the general equilibrium M⁺ (aq) + 1·Cs⁺ (nb) ? 1·M⁺ (nb) + Cs⁺ (aq) taking place in the two-phase water–nitrobenzene system (M⁺ = Ag⁺, K⁺, Rb⁺, Tl⁺; 1 = 1,3-alternate-25,27-bis(1-octyloxy)calix[4]arene-crown-6; aq is aqueous phase, nb is nitrobenzene phase) were determined. Moreover, the stability constants of the 1·M⁺ complexes in water-saturated nitrobenzene were calculated; they were found to increase in the series of K⁺ < Rb⁺ < Ag⁺ < Tl⁺.     

Synergistic extraction of some univalent cations into nitrobenzene by using cesium dicarbollylcobaltate and dibenzo-30-crown-10

From extraction experiments and γ-activity measurements, the exchange extraction constants corresponding to the general equilibrium M⁺(aq) + 1·Cs⁺(nb) ? 1·M⁺(nb) + Cs⁺(aq) taking place in the two-phase water–nitrobenzene system (M⁺ = Li⁺, Na⁺, H⁺, NH₄ ⁺, Ag⁺, K⁺, Rb⁺, Tl⁺; 1 = dibenzo-30-crown-10; aq = aqueous phase, nb = nitrobenzene phase) were determined. Furthermore, the stability constants of the 1·M⁺ complexes in water-saturated nitrobenzene were calculated; they were found to increase in the series of Cs⁺ < H⁺, Ag⁺ < NH₄ ⁺ < Na⁺ < Rb⁺ < Li⁺ < K⁺, Tl⁺.     

Extraction of NH4 +, K+, Rb+ and Tl+ into nitrobenzene using cesium dicarbollylcobaltate in the presence of dibenzo-21-crown-7

Summary From extraction experiments and g-activity measurements, the exchange extraction constants corresponding to the general equilibrium M⁺(aq) + CsL⁺(nb) ? ML⁺(nb) + Cs⁺(aq) taking place in the two-phase water-nitrobenzene system (M⁺ = NH, K⁺, Rb⁺, Tl⁺; L = dibenzo-21-crown-7; aq = aqueous phase, nb = nitrobenzene phase) were evaluated. Further, the stability constants of the ML⁺ complexes in water saturated nitrobenzene were calculated; they were found to increase in the order Cs⁺<K⁺ = Rb⁺?NH<Tl⁺.     

Complexation of the cesium cation with nonactin: extraction and DFT study

From extraction experiments and γ-activity measurements, the extraction constant corresponding to the equilibrium Cs⁺(aq) + A^?(aq) + 1(nb) ? 1·Cs⁺(nb) + A^?(nb) taking place in the two-phase water–nitrobenzene system (A^? = picrate, 1 = nonactin; aq = aqueous phase, nb = nitrobenzene phase) was evaluated as log K _ex (1·Cs⁺,A^?) = 2.8 ± 0.1. Further, the stability constant of the 1·Cs⁺ complex in nitrobenzene saturated with water was calculated for a temperature of 25 °C: log β _nb (1·Cs⁺) = 4.7 ± 0.1. Finally, by using quantum–mechanical DFT calculations, the most probable structure of the resulting cationic complex species 1·Cs⁺ was derived.     

Synergistic extraction of some univalent cations into nitrobenzene by using cesium dicarbollylcobaltate and calix[4]arene-bis(t-octylbenzo-18-crown-6)

From extraction experiments and γ-activity measurements, the exchange extraction constants corresponding to the general equilibrium M⁺ (aq) + CsL⁺ (nb) ? ML⁺ (nb) + Cs⁺ (aq) taking place in the two–phase water–nitrobenzene system (M⁺ = K⁺, Rb⁺, $ {\text{NH}}_{4}^{ + } $ , Ag⁺, Tl⁺; L = calix[4]arene-bis(t-octylbenzo-18-crown-6); aq = aqueous phase, nb = nitrobenzene phase) were evaluated. Furthermore, the stability constants of the ML⁺ complexes in nitrobenzene saturated with water were calculated; they were found to increase in the following cation order: $ {\text{NH}}_{4}^{ + } $  < K⁺ < Ag⁺ < Rb⁺ < Tl⁺.     

Complexation of the cesium cation with 1,3-alternate-25,27-bis(1-octyloxy)calix[4]arene-crown-6

From extraction experiments and γ-activity measurements, the extraction constant corresponding to the equilibrium Cs⁺(aq) + I^?(aq) + 1(nb) ? 1·Cs⁺(nb) + I^?(nb) taking place in the two–phase water–nitrobenzene system (1 = 1,3-alternate-25,27-bis(1-octyloxy)calix[4]arene-crown-6; aq = aqueous phase, nb = nitrobenzene phase) was evaluated as log K _ex (1·Cs⁺, I^?) = 2.9 ± 0.1. Further, the stability constant of the 1·Cs⁺ complex in nitrobenzene saturated with water was calculated for a temperature of 25 °C: log β_nb (1·Cs⁺) = 8.8 ± 0.1. Finally, by using quantum–mechanical DFT calculations, the most probable structure of the resulting cationic complex species 1·Cs⁺ was derived.     

Extraction and theoretical study on the complexation of the strontium cation with beauvericin

From extraction experiments and γ-activity measurements, the extraction constant corresponding to the equilibrium Sr²⁺(aq) + 2A^?(aq) +1(nb) ? 1·Sr²⁺(nb) + 2A^?(nb) taking place in the two-phase water–nitrobenzene system (A^? = picrate, 1 = beauvericin; aq = aqueous phase, nb = nitrobenzene phase) was evaluated as log K _ex(1·Sr²⁺,2A^?) = ?0.6 ± 0.1. Further, the stability constant of the 1·Sr²⁺ complex in nitrobenzene saturated with water was calculated for a temperature of 25 °C: log β _nb(1·Sr²⁺) = 8.5 ± 0.1. Finally, by using quantum-mechanical DFT calculations, the most probable structure of the resulting cationic complex 1·Sr²⁺ was derived.     

Interactions of some protonated α-amino acid methyl esters with hexaethyl p-tert-butylcalix[6]arene hexaacetate in nitrobenzene saturated with water

The exchange extraction constants corresponding to the general equilibrium C⁺(aq) + 1·Cs⁺(nb) ? 1·C⁺ (nb) + Cs⁺(aq) occurring in the two-phase water–nitrobenzene system (C⁺ = protonated α-amino acid methyl ester, 1 = hexaethyl p-tert-butylcalix[6]arene hexaacetate; aq = aqueous phase, nb = nitrobenzene phase) were evaluated on the basis of extraction experiments and γ-activity measurements. Further, the stability constants of the 1·C⁺ cationic complex species in nitrobenzene saturated with water were calculated; they were found to increase in the following cation order: protonated l-tryptophan methyl ester < protonated l-phenylalanine methyl ester < protonated l-leucine methyl ester < protonated l-methionine methyl ester < protonated l-valine methyl ester.     

Complexation of some univalent organic cations with benzo-18-crown-6 in nitrobenzene saturated with water

From extraction experiments and γ-activity measurements, the exchange extraction constants corresponding to the general equilibrium C⁺(aq) + 1·Na⁺(nb) ? 1·C⁺(nb) + Na⁺(aq) taking place in the two-phase water–nitrobenzene system (C⁺ = univalent organic cation, 1 = benzo-18-crown-6; aq = aqueous phase, nb = nitrobenzene phase) were evaluated. Moreover, the stability constants of the 1·C⁺ complex species in nitrobenzene saturated with water were calculated; they were found to increase in the following cation order: protonated tyramine, protonated l-valine methyl ester < protonated dopamine < protonated serotonin < methylammonium < protonated hexamethylenetetramine < ethanolammonium < protonated dl-noradrenaline.     

Extraction and theoretical study on complexation of the strontium cation with antamanide

By using extraction experiments and γ-activity measurements, the extraction constant corresponding to the equilibrium Sr²⁺(aq) + 2A^?(aq) + 1(nb) ? 1·Sr²⁺(nb) + 2A^?(nb) occurring in the two-phase water–nitrobenzene system (A^? = picrate, 1 = antamanide; aq = aqueous phase, nb = nitrobenzene phase) was determined as log K _ex (1·Sr²⁺, 2A^?) = ?0.3 ± 0.1. Further, the stability constant of the 1·Sr²⁺ complex in nitrobenzene saturated with water was calculated for a temperature of 25 °C: log β _nb (1·Sr²⁺) = 8.8 ± 0.1. Finally, applying quantum mechanical density functional level of theory calculations, the most probable structure of the cationic complex species 1·Sr²⁺ was derived. In the resulting complex, the “central” cation Sr²⁺ is bound by six bond interactions to the corresponding six oxygen atoms of the parent ligand 1. The interaction energy of the considered 1·Sr²⁺ complex was found to be ?1,114.9 kJ/mol, confirming the formation of this cationic species as well.     

Solvent extraction of europium trifluoromethanesulfonate into nitrobenzene by using three electroneutral receptors

From extraction experiments and $ \gamma $ -activity measurements, the extraction constants corresponding to the general equilibrium Eu³⁺(aq) + 3 A^?(aq) + L(nb) $ \Leftrightarrow $ EuL³⁺(nb) + 3A^?(nb) taking place in the two-phase water–nitrobenzene system ( $ {\text{A}}^{ - } = {\text{CF}}_{ 3} {\text{SO}}_{3}^{ - } $ ; L = electroneutral receptors denoted by 1, 2, and 3 – see Scheme 1; aq = aqueous phase, nb = nitrobenzene phase) were evaluated. Further, the stability constants of the EuL³⁺ complexes in nitrobenzene saturated with water were calculated; they were found to increase in the series of 3 < 2 < 1.

Complexation of the cesium cation with lithium ionophore VIII: extraction and DFT study

From extraction experiments and γ-activity measurements, the extraction constant corresponding to the equilibrium Cs⁺(aq) + 1·Na ⁺ (nb) = 1·Cs⁺(nb) + Na⁺(aq) taking place in the two-phase water-nitrobenzene system (1 = lithium ionophore VIII; aq = aqueous phase, nb = nitrobenzene phase) was evaluated as log K _ex (Cs⁺, 1·Na⁺) = ?0.5 ± 0.1. Further, the stability constant of the 1·Cs⁺ complex in nitrobenzene saturated with water was calculated for a temperature of 25 °C: log β _nb (1·Cs⁺) = 4.8 ± 0.2. Finally, by using quantum mechanical DFT calculations, the most probable structure of the cationic complex species 1·Cs⁺ was derived. In the resulting complex, the “central” cation Cs⁺ is bound by six bond interactions to the corresponding six oxygen atoms of the parent ligand 1.     

Experimental and DFT study on the complexation of Ba2+ with beauvericin

From extraction experiments and γ-activity measurements, the exchange extraction constant corresponding to the equilibrium Ba²⁺(aq) + 1·Sr²⁺(nb) ?1·Ba²⁺(nb) + Sr²⁺(aq) taking place in the two-phase water–nitrobenzene system (1 = beauvericin; aq = aqueous phase, nb = nitrobenzene phase) was evaluated as log K _ex (Ba²⁺, 1·Sr²⁺) = 1.2 ± 0.1. Further, the stability constant of the beauvericin–barium complex (abbrev. 1·Ba²⁺) in nitrobenzene saturated with water was calculated for a temperature of 25 °C: log β _nb (1·Ba²⁺) = 9.5 ± 0.2. Finally, by using quantum mechanical DFT calculations, the most probable structure of the 1·Ba²⁺ complex species was predicted.     

Complexation of some univalent organic cations with hexaethyl p-tert-butylcalix[6]arene hexaacetate in nitrobenzene saturated water

From extraction experiments and γ-activity measurements, the exchange extraction constants corresponding to the general equilibrium C⁺(aq) + 1·Cs⁺(nb) ?1·C⁺ (nb) + Cs⁺(aq) taking place in the two–phase water–nitrobenzene system (C⁺ = methylammonium, ethylammonium, propylammonium, ethanolammonium, diethanolammonium, triethanolammonium, protonated tyramine, protonated dopamine, protonated DL–noradrenaline; 1 = hexaethyl p-tert-butylcalix[6]arene hexaacetate; aq = aqueous phase, nb = nitrobenzene phase) were evaluated. Furthermore, the stability constants of the 1·C⁺ complex species in nitrobenzene saturated with water were calculated; they were found to increase in the following cation order: protonated tyramine < protonated dopamine < triethanolammonium < diethanolammonium < protonated DL-noradrenaline < propylammonium < ethanolammonium < ethylammonium < methylammonium.     

Experimental and theoretical study on the complexation of Ca2+ with beauvericin

From extraction experiments and γ-activity measurements, the exchange extraction constant corresponding to the equilibrium Ca²⁺(aq) + 1·Sr²⁺(nb) ? 1·Ca²⁺(nb) + Sr²⁺(aq) taking place in the two-phase water–nitrobenzene system (1 = beauvericin; aq = aqueous phase, nb = nitrobenzene phase) was evaluated as log K _ex(Ca²⁺, 1·Sr²⁺) = 1.1 ± 0.1. Further, the stability constant of the 1·Ca²⁺ complex in nitrobenzene saturated with water was calculated for a temperature of 25 °C: log β _nb(1·Ca²⁺) = 10.1 ± 0.2. Finally, by using quantum mechanical density functional level of theory calculations, the most probable structures of the non-hydrated 1·Ca²⁺ and hydrated 1·Ca²⁺·H₂O complex species were predicted.     

Synergistic extraction of some divalent metal cations into nitrobenzene by using strontium dicarbollylcobaltate and electroneutral macrocyclic lactam receptor

From extraction experiments and $ \gamma $ -activity measurements, the exchange extraction constants corresponding to the general equilibrium M²⁺(aq) + 1·Sr²⁺(nb) $ \Leftrightarrow $ 1·M²⁺(nb) + Sr²⁺(aq) taking place in the two-phase water–nitrobenzene system (M²⁺ = Mg²⁺, Ca²⁺, Ba²⁺, Pb²⁺, Cu²⁺, Zn²⁺, Cd²⁺, $ {\hbox{UO}}_{2}^{2 + } $ , Mn²⁺, Co²⁺, Ni²⁺; 1 = macrocyclic lactam receptor–see Scheme 1; aq = aqueous phase, nb = nitrobenzene phase) were evaluated. Moreover, the stability constants of the 1·M²⁺ complexes in nitrobenzene saturated with water were calculated; they were found to increase in the following cation order: Mg²⁺ < Co²⁺ < Cu²⁺, Mn²⁺, Ni²⁺ < Cd²⁺ < Ca²⁺ < Ba²⁺, Zn²⁺ < Pb²⁺ <  $ {\hbox{UO}}_{2}^{2 + } $ .

Solvent extraction of H3O+, NH4+, Ag+, K+, Rb+ and Tl+ into nitrobenzene by using cesium dicarbollylcobaltate in the presence of a hexaarylbenzene-based receptor

From extraction experiments and γ-activity measurements, the extraction constants corresponding to the general equilibrium M⁺(aq) + 1·Cs⁺(nb) \rightleftarrows \rightleftarrows 1·M⁺(nb) + Cs⁺(aq) taking part in the two-phase water–nitrobenzene system (1 = hexaarylbenzene-based receptor; M⁺ = H₃O⁺, NH₄ ⁺, Ag⁺, K⁺, Rb⁺, Tl⁺; aq = aqueous phase, nb = nitrobenzene phase) were evaluated. Furthermore, the stability constants of the ML⁺ complex species in nitrobenzene saturated with water were calculated; they were found to increase in the series of Rb⁺ < K⁺ < Ag⁺, Tl⁺ < H₃O⁺, NH₄ ⁺.     

Extraction of some univalent cations into phenyltrifluoromethyl sulfone by using sodium dicarbollylcobaltate in the presence of benzo-18-crown-6

From extraction experiments and γ-activity measurements, the exchange extraction constants corresponding to the general equilibrium M⁺ (aq) + 1·Na⁺ (org) $ \Leftrightarrow $ 1·M⁺ (org) + Na⁺ (aq) taking place in the two-phase water–phenyltrifluoromethyl sulfone (abbrev. FS 13) system (M⁺ = Li⁺, H₃O⁺, NH₄ ⁺, Ag⁺, Tl⁺, K⁺, Rb⁺, Cs⁺; 1 = benzo-18-crown-6; aq = aqueous phase, org = FS 13 phase) were evaluated. Further, the stability constants of the 1·M⁺ complexes in FS 13 saturated with water were calculated; they were found to increase in the series of $ {\text{Cs}}^{ + } \, < \,{\text{Rb}}^{ + } \, < \,{\text{H}}_{ 3} {\text{O}}^{ + } \, < \,{\text{Ag}}^{ + } \, < \,{\text{Li}}^{ + } \, < \,{\text{NH}}_{4}^{ + } \, < \,{\text{K}}^{ + } \, < \,{\text{Tl}}^{ + } $ .     

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⁺.     

Stability of the valinomycin-rubidium complex in water saturated nitrobenzene

From the extraction experiments and -activity measurements, the extraction constant corresponding to the Rb⁺(aq)+CsL⁺(nb)RbL⁺(nb)+Cs⁺(aq) equilibrium in the two-phase water-nitrobenzene system (L=valinomycin; aq=aqueous phase, nb=nitrobenzene phase) was evaluated in the form logK _ex (Rb⁺, CsL⁺)=0.9. Further, the stability constant of the valinomycin-rubidium complex in nitrobenzene saturated with water was calculated as log _nb(RbL⁺)=11.7.