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1.
From extraction experiments and γ-activity measurements, the extraction constant corresponding to the equilibrium Mg2+(aq) + 1·Sr2+(nb) ⇆ 1·Mg2+(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 (Mg2+, 1·Sr2+) = 0.0 ± 0.1. Further, the stability constant of the 1·Mg2+ complex in nitrobenzene saturated with water was calculated for a temperature of 25 °C as log βnb (1·Mg2+) = 9.1 ± 0.2. By using quantum mechanical DFT calculations, the most probable structures of the non-hydrated 1·Mg2+ and hydrated 1·Mg2+·3H2O complex species were predicted. 相似文献
2.
Experimental and theoretical study on the complexation of the cesium cation with dibenzo-30-crown-10
E. Makrlík P. Toman P. Vaňura 《Journal of Radioanalytical and Nuclear Chemistry》2012,292(3):1137-1140
From extraction experiments and γ-activity measurements, the extraction constant corresponding to the equilibrium Cs+ (aq) + A− (aq) + 1(nb)
\rightleftarrows \rightleftarrows
1·Cs+(nb) + A−(nb) taking place in the two-phase water–nitrobenzene system (A− = picrate, 1 = dibenzo-30-crown-10; aq = aqueous phase, nb = nitrobenzene phase) was evaluated as log K
ex (1·Cs+, A−) = 4.0 ± 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+) = 5.9 ± 0.1. Finally, by using quantum–mechanical DFT calculations, the most probable structure of the resulting cationic
complex species 1·Cs+ was derived. 相似文献
3.
E. Makrlík P. Toman P. Vaňura P. Selucký R. Rathore 《Journal of Radioanalytical and Nuclear Chemistry》2010,286(1):55-59
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 part in the two-phase water–nitrobenzene system (A− = picrate, 1 = hexaarylbenzene-based receptor; 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 hexaarylbenzene-based receptor·Cs+ complex (abbrev. 1·Cs+) in nitrobenzene saturated with water was calculated for a temperature of 25 °C: log β
nb (1·Cs+) = 4.7 ± 0.1. By using quantum mechanical DFT calculations, the most probable structure of the 1·Cs+ complex species was solved. In this complex having C
3 symmetry, the cation Cs+ synergistically interacts with the polar ethereal oxygen fence and with the central hydrophobic benzene bottom via cation–π
interaction. Finally, the calculated binding energy of the resulting complex 1·Cs+ is −220.0 kJ/mol, confirming relatively high stability of the considered cationic complex species. 相似文献
4.
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 logKex(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 βnb(PbL2+)=12.9±0.1. 相似文献
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 Kex(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 bnb(PbL)=13.2±0.1. 相似文献
6.
From extraction experiments and γ-activity measurements, the exchange extraction constants corresponding to the general equilibrium
M2+(aq) + 1 · Sr2+(nb) ⇔ 1 · M2+(nb) + Sr2+(aq) taking place in the two-phase water–nitrobenzene system (M2+ = Mg2+, Ca2+, Ba2+, Cu2+, Zn2+, Pb2+, Mn2+, Ni2+; 1 = nonactin; 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 order: Mg2+, Mn2+ < Ba2+, Cu2+, Zn2+, Ni2+ < Sr2+ < Ca2+ < Pb2+. 相似文献
7.
Emanuel Makrlík Ji?í Dybal Jan Budka Petr Vaňura 《Monatshefte für Chemie / Chemical Monthly》2009,287(1):1155-1158
Abstract
From extraction experiments and γ-activity measurements, the extraction constant corresponding to the equilibrium H3O+(aq) + 1·Na+(nb) \leftrightarrows \leftrightarrows 1·H3O+ (nb) + Na+ (aq) taking place in the two-phase water–nitrobenzene system (1 = p-tert-butylcalix[4]arenetetrakis(N,N-dimethylacetamide); aq = aqueous phase, nb = nitrobenzene phase) was evaluated as log K ex (H3O+, 1·Na+) = −0.1 ± 0.1. Further, the stability constant of the 1·H3O+ complex in water-saturated nitrobenzene was calculated for a temperature of 25 °C as log β nb (1·H3O+) = 10.9 ± 0.2. By using quantum mechanical DFT calculations, the most probable structure of the 1·H3O+ cationic complex species was derived. In this complex, the hydroxonium ion H3O+ is bound partly to one phenoxy oxygen atom and partly to two carbonyl oxygens of 1 by strong hydrogen bonds and obviously by other electrostatic interactions. 相似文献8.
E. Makrlík P. Toman P. Vaňura 《Journal of Radioanalytical and Nuclear Chemistry》2013,295(2):1119-1122
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. 相似文献
9.
E. Makrlík P. Toman P. Vaňura V. Kašička R. Rathore 《Journal of solution chemistry》2011,40(8):1418-1426
From extraction experiments and γ-activity measurements, the exchange extraction constant corresponding to the equilibrium Ag+(aq) + 1⋅Cs+(nb) ⇆ 1⋅Ag+(nb) + Cs+(aq) taking part in the two-phase water–nitrobenzene system (where 1 = hexaarylbenzene-based receptor; aq = aqueous phase, nb = nitrobenzene phase) was evaluated to be log 10
K
ex(Ag+, 1⋅Cs+) = −1.0±0.1. Further, the stability constant of the hexaarylbenzene-based receptor⋅Ag+ complex (abbreviation 1⋅Ag+) in nitrobenzene saturated with water, was calculated at a temperature of 25 °C: log 10
β
nb(1⋅Ag+) = 5.5±0.2. By using quantum mechanical DFT calculations, the most probable structure of the 1⋅Ag+ complex species was solved. In this complex having C3 symmetry, the cation Ag+ synergistically interacts with the polar ethereal oxygen fence and with the central hydrophobic benzene ring via cation–π interaction. 相似文献
10.
From extraction experiments and γ-activity measurements, the extraction constant corresponding to the equilibrium
\textCs + ( \textaq ) + \textA - ( \textaq ) + 1( \textnb )\underset \rightleftharpoons 1·\textCs + ( \textnb ) + \textA - ( \textnb ) {\text{Cs}}^{ + } \left( {\text{aq}} \right) + {\text{A}}^{ - } \left( {\text{aq}} \right) + {\mathbf{1}}\left( {\text{nb}} \right)\underset {} \rightleftharpoons {\mathbf{1}}\cdot{\text{Cs}}^{ + } \left( {\text{nb}} \right) + {\text{A}}^{ - } \left( {\text{nb}} \right) taking place in the two-phase water-nitrobenzene system (A− = picrate, 1 = dibenzo-21-crown-7; aq = aqueous phase, nb = nitrobenzene phase) was evaluated as log K
ex (1·Cs+, A−) = 4.4 ± 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 βnb (1·Cs+) = 6.3 ± 0.1. Finally, by using quantum mechanical DFT calculations, the most probable structure of the resulting cationic
complex species 1·Cs+ was solved. 相似文献
11.
Emanuel Makrlík Petr Vaňura Pavel Selucky 《Monatshefte für Chemie / Chemical Monthly》2008,275(2):597-600
From extraction experiments and γ-activity measurements, the exchange extraction constants corresponding to the general equilibrium
M
2+ (aq) + 1 · Sr2+ (nb) ⇄ 1 · M
2+ (nb) + Sr2+ (aq) taking place in the two-phase water-nitrobenzene system (M
2+ = Cu2+, Zn2+, Cd2+, Pb2+, UO2
2+, Fe2+, Co2+, and Ni2+; 1 = valinomycin; aq = aqueous phase, nb = nitrobenzene phase) were evaluated. Moreover, the stability constants of the 1 · M
2+ complexes in water saturated nitrobenzene were calculated; they were found to increase in the order Fe2+ < Cd2+, Co2+ < Ni2+ < UO2
2+, Zn2+ < Cu2+ < Pb2+. 相似文献
12.
E. Makrlík P. Vańura V. Bečková 《Journal of Radioanalytical and Nuclear Chemistry》1999,241(3):659-661
From extraction experiments and γ-activity measurements, the extraction constant corresponding to the equilibrium Pb2+(aq)+SrL2
2+(nb)⇆PbL2
2+(nb)+Sr2+(aq) taking place in the two-phase water-nitrobenzene system (L=15-crown-5; aq = aqueous phase, nb = nitrobenzene phase) was
evaluated: logK
ex (Pb2+,SrL2
2+)=3.0. Further, the stability constant of the PbL2
2+ complex in nitrobenzene saturated with water was calculated: log βnb(PbL
2
2+
)=17.8 相似文献
13.
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 = valinomycin; aq = aqueous phase, nb = nitrobenzene phase) was evaluated as log K
ex (Ca2+, 1·Sr2+) = 2.4±0.1. Further, the stability constant of the valinomycin-calcium complex (abbrev. 1·Ca2+) in nitrobenzene saturated with water was calculated for a temperature of 25 °C: log β
nb (1·Ca2+) = 8.3±0.1. By using quantum mechanical DFT calculations, the most probable structure of the 1·Ca2+·2H2O complex species was predicted. In this complex, the “central” Ca2+ cation is bound by strong bonds to two oxygen atoms of the respective water molecules and to four ester carbonyl oxygens
of the parent valinomycin ligand 1. Finally, the calculated binding energy of the considered complex 1·Ca2+·2H2O is −319.2 kcal/mol, which confirms the relatively high stability of this cationic complex species. 相似文献
14.
Emanuel Makrlík Petr Vaňura Pavel Selucký 《Monatshefte für Chemie / Chemical Monthly》2008,139(6):597-600
From extraction experiments and γ-activity measurements, the exchange extraction constants corresponding to the general equilibrium
M
2+ (aq) + 1 · Sr2+ (nb) ⇄ 1 · M
2+ (nb) + Sr2+ (aq) taking place in the two-phase water-nitrobenzene system (M
2+ = Cu2+, Zn2+, Cd2+, Pb2+, UO2
2+, Fe2+, Co2+, and Ni2+; 1 = valinomycin; aq = aqueous phase, nb = nitrobenzene phase) were evaluated. Moreover, the stability constants of the 1 · M
2+ complexes in water saturated nitrobenzene were calculated; they were found to increase in the order Fe2+ < Cd2+, Co2+ < Ni2+ < UO2
2+, Zn2+ < Cu2+ < Pb2+.
Correspondence: Emanuel Makrlík, Faculty of Applied Sciences, University of West Bohemia, Pilsen, Czech Republic. 相似文献
15.
Emanuel Makrlík J. Budka P. Vaňura P. Selucky 《Monatshefte für Chemie / Chemical Monthly》2009,287(3):157-160
Abstract
From extraction experiments and γ-activity measurements, the exchange extraction constants corresponding to the general equilibrium \textM2 + ( \textaq ) + 1 ·\textSr2 + ( \textnb ) \rightleftarrows 1 ·\textM2 + ( \textnb ) + \textSr2 + ( \textaq ) {\text{M}}^{2 + } \left( {\text{aq}} \right) + {\mathbf{1}} \cdot {\text{Sr}}^{2 + } \left( {\text{nb}} \right) \rightleftarrows {\mathbf{1}} \cdot {\text{M}}^{2 + } \left( {\text{nb}} \right) + {\text{Sr}}^{2 + } \left( {\text{aq}} \right) taking place in the two-phase water–nitrobenzene system (M2+ = Ca2+, Ba2+, Cu2+, Zn2+, Cd2+, Pb2+, UO2 2+, Mn2+, Co2+, Ni2+; 1 = tetraphenyl p-tert-butylcalix[4]arene tetraketone; aq = aqueous phase, nb = nitrobenzene phase) were evaluated. Further, the stability constants of the 1 · M2+ complexes in water-saturated nitrobenzene were calculated; they were found to increase in the cation order Ba2+, Mn2+ < Co2+ < Cu2+, Ni2+ < Zn2+, Cd2+, UO2 2+ < Ca2+ < Pb2+. 相似文献16.
E. Makrlík P. Vaňura S. Böhm P. Ruzza 《Journal of Radioanalytical and Nuclear Chemistry》2014,300(3):1291-1294
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. 相似文献
17.
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. 相似文献
18.
E. Makrlík P. Toman P. Vaňura 《Journal of Radioanalytical and Nuclear Chemistry》2013,295(3):1887-1891
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. 相似文献
19.
From extraction experiments and γ-activity measurements, the extraction constant corresponding to the equilibrium H+(aq) + 1
·Na+(nb) ⇆ 1
·H+(nb) + Na+(aq) taking place in the two-phase water-nitrobenzene system (1 = p-tert-butylcalix[4]arene-tetrakis(N, N-diethylacetamide); aq = aqueous phase, nb = nitrobenzene phase) was evaluated as log K
ex(H+, 1
·Na+) = −1.4 ± 0.1. Further, the stability constant of the p-tert-butylcalix[4]arene-tetrakis(N,N-diethylacetamide)-H+ complex in water saturated nitrobenzene was calculated for a temperature of 25°C as log βnb(1
· H+) = 8.1 ± 0.1. 相似文献
20.
Summary. From extraction experiments and γ-activity measurements, the extraction constant corresponding to the equilibrium H+(aq) + 1
·Na+(nb) ⇆ 1
·H+(nb) + Na+(aq) taking place in the two-phase water-nitrobenzene system (1 = p-tert-butylcalix[4]arene-tetrakis(N, N-diethylacetamide); aq = aqueous phase, nb = nitrobenzene phase) was evaluated as log K
ex(H+, 1
·Na+) = −1.4 ± 0.1. Further, the stability constant of the p-tert-butylcalix[4]arene-tetrakis(N,N-diethylacetamide)-H+ complex in water saturated nitrobenzene was calculated for a temperature of 25°C as log βnb(1
· H+) = 8.1 ± 0.1. 相似文献