scholarly journals Solvent extraction of Ca2+, Ba2+, Cu2+, Zn2+, Cd2+, Pb2+, UO22+, Mn2+, Co2+ and Ni2+ into nitrobenzene using strontium dicarbollylcobaltate and tetra-tert-butyl p-tert-butylcalix[4]arene tetraacetate

2008 ◽  
Vol 73 (12) ◽  
pp. 1181-1186 ◽  
Author(s):  
E. Makrlík ◽  
J. Budka ◽  
P. Vaňura ◽  
P. Selucký
Keyword(s):  
Two Phase ◽  
Nitrobenzene Phase ◽  
Tert Butyl ◽  
Cation Order ◽  
Activity Measurements ◽  
Extraction Constants ◽  
Exchange Extraction ◽  
Phase Water ◽  
The Stability ◽  
Water Saturated

The exchange extraction constants corresponding to the general equilibrium M2+(aq) + SrL2+(nb) ? ?ML2+(nb) + Sr2+(aq) occurring in the two- -phase water-nitrobenzene system (M2+ = Ca2+, Ba2+, Cu2+, Zn2+, Cd2+, Pb2+, UO22+ , Mn2+, Co2+ or Ni2+; L = tetra-tert-butyl p-tert-butylcalix[4]arene tetraacetate; aq = aqueous phase; nb = nitrobenzene phase) were evaluated from extraction experiments and ?-activity measurements. Furthermore, the stability constants of the ML2+ complexes in water saturated nitrobenzene were calculated; they were found to increase in the cation order Ba2+ < Mn2+ < Pb2+, Co2+ < Cu2+, Zn2+ < Cd2+, Ni2+ < UO22+ < Ca2+.

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

2012 ◽  
Vol 10 (5) ◽  
pp. 1495-1499
Author(s):  
Emanuel Makrlík ◽  
Petr Vaňura ◽  
Pavel Selucký
Keyword(s):  
Cationic Complex ◽  
Two Phase ◽  
Complex Species ◽  
Nitrobenzene Phase ◽  
Cation Order ◽  
Activity Measurements ◽  
Extraction Constants ◽  
Univalent Organic Cations ◽  
Phase Water ◽  
The Stability

AbstractFrom 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 +

scholarly journals Stability of the barium-benzo-15-crown-5 complex in nitrobenzene saturated with water

2006 ◽  
Vol 71 (11) ◽  
pp. 1147-1151 ◽  
Author(s):  
E. Makrlík ◽  
P. Vaňura
Keyword(s):  
Stability Constant ◽  
Aqueous Phase ◽  
Extraction Constant ◽  
Two Phase ◽  
Nitrobenzene Phase ◽  
Activity Measurements ◽  
System L ◽  
Exchange Extraction ◽  
Phase Water ◽  
The Stability

From extraction experiments and ?-activity measurements, the exchange extraction constant corresponding to the equilibrium Ba2+(aq) + SrL2 2+(nb) _ BaL 2 2+(nb) + Sr2+(aq) occurring in the two-phase water-nitrobenzene system (L = benzo-15-crown-5; aq = aqueous phase, nb = nitrobenzene phase) was evaluated as log K ex (Ba2+, SrL22+) = 0.3 ? 0.1. Furthermore, the stability constant of the benzo-15-crown-5-barium complex in nitrobenzene saturated with water was calculated for the temperature of 25 ?C: log ?nb (BaL2 2+) = 13.3?0.1.

Calix[4]arene-crown-5 as a selective extraction reagents for K+/H+, Rb+/H+ and Rb+/Cs+ separations

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Petr Vaňura ◽  
Emanuel Makrlík ◽  
Pavel Selucký
Keyword(s):  
Stability Constants ◽  
Aqueous Phase ◽  
Organic Phase ◽  
Selective Extraction ◽  
Nitrobenzene Solution ◽  
Two Phase ◽  
Extraction Constants ◽  
Exchange Extraction ◽  
Phase Water ◽  
The Stability

Abstract From extraction experiments, the exchange extraction constants corresponding to the general equilibriums M+ (aq) + NaL+ (org) ⇔ ML+ (org) + Na+ (aq) or M+ (aq) + CsL+ (org) ⇔ ML+ (org) + Cs+ (aq), which take place in the two-phase water–nitrobenzene extraction system (M+ = Li+, H3O+, Ag+, K+, NH4 +, Tl+, Rb+; L = calix[4]arene-bis crown5(1,3-alternate), 26,28-dipropoxycalix[4]arene-crown-5(1,3-alternate), 11,23-dibromo-25,28-dipropoxycalix[4]arene-crown-5 (1,3-alternate) and 1,3-alternate-25,27-dihydroxycalix[4]arene-crown-5; aq = aqueous phase, org = organic phase), were evaluated. The stability constants of the NaL+ and CsL+ complexes were calculated from the extraction of the respective picrates in the system of water–nitrobenzene solution of L. Further, the stability constants of the ML+ complexes in nitrobenzene saturated with water were determined. High selectivities were found in some systems under study.

scholarly journals Extraction of calcium from water into nitrobenzene using strontium dicarbollylcobaltate in the presence of 18-crown-6

2000 ◽  
Vol 65 (4) ◽  
pp. 275-279
Author(s):  
Marcela Danková ◽  
Emanuel Makrlík ◽  
Petr Vanura
Keyword(s):  
Stability Constant ◽  
Aqueous Phase ◽  
Extraction Constant ◽  
Two Phase ◽  
Nitrobenzene Phase ◽  
Activity Measurements ◽  
System L ◽  
Phase Water ◽  
The Stability

From extraction experiments and g-activity measurements, the extraction constant corresponding to the equilibrium Ca 2+ (aq)+ SrL 2+ (nb) === CaL 2+ (nb) + Sr 2+ (aq) taking place in the two-phase water-nitrobenzene system(L= 18-crown-6, aq = aqueous phase, nb = nitrobenzene phase) was evaluated as log Kex(Ca 2+, SrL 2+) = -1.9 ?0.1. Furthermore, the stability constant of the calcium - 18-crown-6 complex in nitrobenzene saturated with water was calculated for the temperature of 25?C: log bnb (CaL 2+)=10.1?0.1.

Ionic product of water in the nitrobenzene phase of the two-phase water-nitrobenzene extraction system

1991 ◽  
Vol 56 (4) ◽  
pp. 760-763
Author(s):  
Emanuel Makrlík
Keyword(s):  
Thermodynamic Parameters ◽  
Extraction System ◽  
Two Phase ◽  
Nitrobenzene Phase ◽  
Ionic Product ◽  
Phase Water ◽  
General Relations

General relations among thermodynamic parameters, which characterize the transfer of the ions H+ and OH- from the aqueous into nitrobenzene phase of the two-phase water-nitrobenzene extraction system and dissociation equilibria of H2O in both phases of this system, have been derived. Further, using the known parameters ionic product of water in nitrobenzene saturated with water has been evaluated for a temperature of 25°C: PnbH2O = 10-29.2 mol2 dm-6.

Contribution to the thermodynamics of complexes of alkali metal cations with dibenzo-18-crown-6 in water-nitrobenzene extraction system

1984 ◽  
Vol 49 (1) ◽  
pp. 39-44 ◽  
Author(s):  
Emanuel Makrlík ◽  
Jaroslava Hálová ◽  
Miroslav Kyrš
Keyword(s):  
Alkali Metal ◽  
Alkali Metal Cation ◽  
Alkali Metal Cations ◽  
Complex Species ◽  
Cation Order ◽  
Extraction Constants ◽  
Equilibrium Data ◽  
Individual Extraction Constants ◽  
The Stability ◽  
The Individual

The stability constants for the ML+ complex species, where M+ is an alkali metal cation and L is dibenzo-18-crown-6, in nitrobenzene saturated with water were calculated by employing published equilibrium data. The stability is found to increase in the cation order Li+ < Cs+ < Rb+ < K+ < Na+. For the NaL+, KL+, RbL+, and CsL+ complex cations the individual extraction constants in the water-nitrobenzene system were determined; their values increase in the series Na+ < K+ < Rb+ < Cs+.

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