Voltammetric study of complexing sodium cation with dibenzo-18-crown-6 in nitrobenzene phase of two-phase water-nitrobenzene extraction system

1983 ◽  
Vol 28 (6) ◽  
pp. 847-851 ◽  
Author(s):  
E. Makrlík ◽  
L.Q. Hung ◽  
A. Hofmanová
Keyword(s):  
Sodium Cation ◽  
Extraction System ◽  
Two Phase ◽  
Nitrobenzene Phase ◽  
Voltammetric Study ◽  
Phase Water

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 bromophenol blue in the two-phase water-nitrobenzene extraction system

1990 ◽  
Vol 55 (11) ◽  
pp. 2606-2609 ◽  
Author(s):  
Emanuel Makrlík
Keyword(s):  
Equilibrium Distribution ◽  
Dissociation Constants ◽  
Extraction System ◽  
Bromophenol Blue ◽  
Phase Extraction ◽  
Distribution Constant ◽  
Two Phase ◽  
Nitrobenzene Phase ◽  
Phase Water ◽  
General Relations

General relations among thermodynamic parameters characterizing dissociation equilibria with species H2A, HA- and A2- (H2A is a symbol for an electroneutral undissociated acid) in a two-phase extraction system have been derived. From the extraction measurements, the equilibrium distribution constant of electroneutral bromophenol blue between the nitrobenzene phase and the aqueous one has been determined: log KD(H2A) = 3.60 ± 0.01. By using this value and further known constants and applying the mentioned relations the following values of dissociation constants of bromophenol blue in nitrobenzene saturated with water have been calculated for a temperature of 25 °C: pKaorg(H2A) = -log Kaorg(H2A) = 10.1 and pKaorg(HA-) = -log Kaorg(HA-) = 14.5.

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.

scholarly journals Distribution of micro-amounts of europium in the two-phase water-HCl-nitrobenzene-N,N'-dimethyl-N,N'-diphenyl-2,6-dipicolinamide-hydrogen dicarbollylcobaltate extraction system

2009 ◽  
Vol 74 (7) ◽  
pp. 781-787 ◽  
Author(s):  
Emanuel Makrlík ◽  
Petr Vaňura ◽  
Pavel Selucký ◽  
Vasily Babain ◽  
Ivan Smirnov
Keyword(s):  
Stability Constants ◽  
Organic Phase ◽  
Extraction And Stability Constants ◽  
Extraction System ◽  
Hydrogen Dicarbollylcobaltate ◽  
Nitrobenzene Solution ◽  
Two Phase ◽  
Equilibrium Data ◽  
Phase Water

Extraction of micro-amounts of europium by a nitrobenzene solution of hydrogen dicarbollylcobaltate (H+B-) in the presence of N,N'-dimethyl- -N,N'-diphenyl-2,6-dipicolinamide (MePhDPA, L) was investigated. The equilibrium data were explained assuming that the species HL+, + HL2 , 3+ EuL2 and 3+ EuL3 are extracted into the organic phase. The values of the extraction and stability constants of the species in nitrobenzene saturated with water were determined.

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+.

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