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1.
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 C 3 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
2.
On the basis of extraction experiments and γ-activity measurements, the extraction constant corresponding to the equilibrium Pb2+(aq) + 1·Sr2+(nb) ? 1·Pb2+(nb) + Sr2+(aq) occurring in the two-phase water–nitrobenzene system (1 = cyclosporin A; aq = aqueous phase, nb = nitrobenzene phase) was evaluated as log K
ex (Pb2+, 1·Sr2+) = 0.1 ± 0.1. Further, the stability constant of the 1·Pb2+ complex in nitrobenzene saturated with water was calculated for a temperature of 25 °C: log β
nb (1·Pb2+) = 9.2 ± 0.2. Finally, applying quantum chemical DFT calculations, the most probable structure of the proven 1·Pb2+ cationic complex species was derived. In the resulting complex, the “central” cation Pb2+ is bound by four bonding interactions to the corresponding four oxygen atoms of the parent cyclosporin A ligand. The interaction energy, E(int), of the considered 1·Pb2+ complex was found to be ?1016.3 kJ/mol, confirming also the formation of this complex. 相似文献
3.
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
4.
From extraction experiments and γ-activity measurements, the exchange extraction constants corresponding to the general equilibrium
M 2+(aq) + 1 · Sr 2+(nb) ⇔ 1 · M 2+(nb) + Sr 2+(aq) taking place in the two-phase water–nitrobenzene system (M 2+ = Mg 2+, Ca 2+, Ba 2+, Cu 2+, Zn 2+, Pb 2+, Mn 2+, Ni 2+; 1 = nonactin; aq = aqueous phase, nb = nitrobenzene phase) were evaluated. Moreover, the stability constants of the 1 · M 2+ complexes in nitrobenzene saturated with water were calculated; they were found to increase in the following order: Mg 2+, Mn 2+ < Ba 2+, Cu 2+, Zn 2+, Ni 2+ < Sr 2+ < Ca 2+ < Pb 2+. 相似文献
5.
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
6.
From extraction experiments and γ-activity measurements, the exchange extraction constant corresponding to the equilibrium Ca 2+ (aq)+ 1·Sr 2+ (nb) ⇆ 1·Ca 2+ (nb) + Sr 2+ (aq) taking place in the two-phase water-nitrobenzene system ( 1 = valinomycin; aq = aqueous phase, nb = nitrobenzene phase) was evaluated as log K
ex (Ca 2+, 1·Sr 2+) = 2.4±0.1. Further, the stability constant of the valinomycin-calcium complex (abbrev. 1·Ca 2+) in nitrobenzene saturated with water was calculated for a temperature of 25 °C: log β
nb ( 1·Ca 2+) = 8.3±0.1. By using quantum mechanical DFT calculations, the most probable structure of the 1·Ca 2+·2H 2O complex species was predicted. In this complex, the “central” Ca 2+ 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·Ca 2+·2H 2O is −319.2 kcal/mol, which confirms the relatively high stability of this cationic complex species. 相似文献
7.
Abstract From extraction experiments and γ-activity measurements, the extraction constant corresponding to the equilibrium H 3O +(aq) + 1·Na +(nb)
\leftrightarrows \leftrightarrows
1·H 3O + (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 (H 3O +, 1·Na +) = −0.1 ± 0.1. Further, the stability constant of the 1·H 3O + complex in water-saturated nitrobenzene was calculated for a temperature of 25 °C as log β
nb ( 1·H 3O +) = 10.9 ± 0.2. By using quantum mechanical DFT calculations, the most probable structure of the 1·H 3O + cationic complex species was derived. In this complex, the hydroxonium ion H 3O + 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.
From extraction experiments and γ-activity measurements, the extraction constant corresponding to the equilibrium
\text Cs + ( \text aq ) + \text A - ( \text aq ) + 1( \text nb )\underset \rightleftharpoons 1·\text Cs + ( \text nb ) + \text A - ( \text nb ) {\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 β nb ( 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
9.
From extraction experiments and γ-activity measurements, the extraction constant corresponding to the equilibrium Sr 2+(aq) + 2A ?(aq) + 1(nb) ? 1·Sr 2+(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·Sr 2+,2A ?) = ?0.6 ± 0.1. Further, the stability constant of the 1·Sr 2+ complex in nitrobenzene saturated with water was calculated for a temperature of 25 °C: log β nb( 1·Sr 2+) = 8.5 ± 0.1. Finally, by using quantum-mechanical DFT calculations, the most probable structure of the resulting cationic complex 1·Sr 2+ was derived. 相似文献
10.
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 + = H 3O +, NH 4
+, 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 + < H 3O +, NH 4
+. 相似文献
11.
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 β nb( 1
· H +) = 8.1 ± 0.1. 相似文献
12.
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 β nb( 1
· H +) = 8.1 ± 0.1. 相似文献
13.
From extraction experiments and γ-activity measurements, the extraction constant corresponding to the equilibrium 2Li +(aq)+SrL 2
2+(nb) 2LiL +(nb)+Sr 2+(aq) taking place in the two-phase water-nitrobenzene system (L=15-crown-5; aq=aqueous phase, nb=nitrobenzene phase) was evaluated
as log K
ex
(2Li +;SrL 2
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. 相似文献
14.
From extraction experiments and γ-activity measurements, the exchange extraction constants corresponding to the general equilibrium
M 2+(aq)+SrL 2+(nb)⇔ML 2+(nb)+Sr 2+(aq) taking place in the two-phase water-nitrobenzene system (M 2+ = Ba 2+, Pb 2+, Cd 2+; L = tetramethyl p-tert-butylcalix[4]arene tetraketone; aq = aqueous phase, nb = nitrobenzene phase) were evaluated. Moreover, the stability constants
of the ML 2+ complexes in water saturated nitrobenzene were calculated; they were found to increase in the order Ba 2+<Cd 2+<Pb 2+. 相似文献
15.
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 + = methylammonium, ethylammonium, propylammonium, ethanolammonium, diethanolammonium, triethanolammonium, cation TRIS+, hydrazinium, hydroxylammonium; 1 = benzo-18-crown-6; aq = aqueous phase, nb = nitrobenzene phase) were evaluated. Furthermore, 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: triethanolammonium < propylammonium < ethylammonium, diethanolammonium < methylammonium < ethanolammonium < cation TRIS + < hydrazinium < hydroxylammonium. 相似文献
16.
From extraction experiments and γ-activity measurements, the exchange extraction constant corresponding to the equilibrium Ba 2+(aq) + 1·Sr 2+(nb) ?1·Ba 2+(nb) + Sr 2+(aq) taking place in the two-phase water–nitrobenzene system ( 1 = beauvericin; aq = aqueous phase, nb = nitrobenzene phase) was evaluated as log K ex (Ba 2+, 1·Sr 2+) = 1.2 ± 0.1. Further, the stability constant of the beauvericin–barium complex (abbrev. 1·Ba 2+) in nitrobenzene saturated with water was calculated for a temperature of 25 °C: log β nb ( 1·Ba 2+) = 9.5 ± 0.2. Finally, by using quantum mechanical DFT calculations, the most probable structure of the 1·Ba 2+ complex species was predicted. 相似文献
17.
By using extraction experiments and γ-activity measurements, the extraction constant corresponding to the equilibrium Sr 2+(aq) + 2A ?(aq) + 1(nb) ? 1·Sr 2+(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·Sr 2+, 2A ?) = ?0.3 ± 0.1. Further, the stability constant of the 1·Sr 2+ complex in nitrobenzene saturated with water was calculated for a temperature of 25 °C: log β nb ( 1·Sr 2+) = 8.8 ± 0.1. Finally, applying quantum mechanical density functional level of theory calculations, the most probable structure of the cationic complex species 1·Sr 2+ was derived. In the resulting complex, the “central” cation Sr 2+ is bound by six bond interactions to the corresponding six oxygen atoms of the parent ligand 1. The interaction energy of the considered 1·Sr 2+ complex was found to be ?1,114.9 kJ/mol, confirming the formation of this cationic species as well. 相似文献
18.
From extraction experiments and γ-activity measurements, the exchange extraction constant corresponding to the equilibrium Ca 2+(aq) + 1·Sr 2+(nb) ? 1·Ca 2+(nb) + Sr 2+(aq) taking place in the two-phase water–nitrobenzene system ( 1 = beauvericin; aq = aqueous phase, nb = nitrobenzene phase) was evaluated as log K ex(Ca 2+, 1·Sr 2+) = 1.1 ± 0.1. Further, the stability constant of the 1·Ca 2+ complex in nitrobenzene saturated with water was calculated for a temperature of 25 °C: log β nb( 1·Ca 2+) = 10.1 ± 0.2. Finally, by using quantum mechanical density functional level of theory calculations, the most probable structures of the non-hydrated 1·Ca 2+ and hydrated 1·Ca 2+·H 2O complex species were predicted. 相似文献
19.
From extraction experiments and γ-activity measurements, the exchange extraction constants corresponding to the general equilibrium
M + (aq) + 1·Na + (nb) ⇔ 1·M + (nb) + Na + (aq) taking place in the two-phase water–nitrobenzene system (M + = Li +, H 3O +, NH 4 + {\rm NH}_{4}^{ + } , Ag +, K +, Rb +, Tl +, Cs +; 1 = barium ionophore I; 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 + < Rb + < NH 4 + {\rm NH}_{4}^{ + } , K + < H 3O + < Na + < Ag +, Tl + < Li +. 相似文献
20.
Summary From extraction experiments and γ-activity measurements, the extraction constant corresponding to the equilibrium Pb 2+(aq)+SrL 2+ (nb)↔PbL 2+ (nb)+Sr 2+ (aq) taking place in the two-phase water-nitrobenzene system (L=PEG 400; aq = aqueous phase, nb = nitrobenzene phase) was
evaluated as log Kex(Pb 2+, SrL 2+)=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(PbL 2+)=12.9±0.1. 相似文献
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