The Extraction of Strontium and Barium with a Solution of Bis-1,2-Dicarbollylcobaltate in Nitrobenzene in the Presence of 18-Crown-6

1993 ◽  
Vol 58 (6) ◽  
pp. 1324-1336 ◽  
Author(s):  
Petr Vaňura ◽  
Emanuel Makrlík
Keyword(s):  
Aqueous Solution ◽  
Stability Constants ◽  
Organic Phase ◽  
Perchloric Acid ◽  
Extraction Constants ◽  
Individual Extraction Constants

A study has been made of the extraction of Sr and Ba in an aqueous solution of perchloric acid-18-crown-6-bis-1,2-dicarbollylcobaltate-nitrobenzene. It was found that the organic phase contains complexes of the ML2+org type ( M = Sr2+, Ba2+) that are converted to ML22+org when the concentration of crown (cL) is greater than the concentration of bis-1,2-dicarbollylcobaltate (cB). The values of the corresponding extraction constants, individual extraction constants and stability constants of the extracted species in the organic phase were determined. The system can be utilized for separation applications at concentrations here cL < cB.

Extraction of europium from acidic aqueous solutions into nitrobenzene by dicarbolide in the presence of polyethylene glycol

1984 ◽  
Vol 49 (6) ◽  
pp. 1367-1381 ◽  
Author(s):  
Petr Vaňura ◽  
Marie Benešová ◽  
Emanuel Makrlík ◽  
Miroslav Kyrš ◽  
Jiří Rais
Keyword(s):  
Polyethylene Glycol ◽  
Aqueous Solutions ◽  
Organic Phase ◽  
Perchloric Acid ◽  
Distribution Ratio ◽  
Europium Complexes ◽  
Peg 400 ◽  
Extraction Constants ◽  
Positively Charged ◽  
The Eu

Extraction of microamounts of 152, 154 Eu from the aqueous solutions of perchloric acid (c(HClO4) = 0.1-0.5 mol l-1) was studied in the presence of 3 . 10-4 -0.3 mol l-1 of polyethylene glycol PEG 400 (L) by the nitrobenzene solutions of Co(III)-dicarbolide (3.3'-commo-bis(undecahydro-1,2-dicarba-3-cobalta-closo-dodecarborate) (-1), {(π-(3)-1,2-B9C2H11)2Co}-, henceforth only B-) of the concentration c(dicarbolide) = 10-3-10-1 mol l-1. Maxima of the Eu distribution ratio dependence on the concentration of polyethylene glycol are explained by the competition reactions between the positively charged europium complexes (EuL3+, EuLH-12+, and EuL23+, EuL2H-22+, or EuL33+) and protonized polyethylene glycol (HL+) in the organic phase. The respective equilibrium extraction constants were determined.

Extraction of some metals into solutions of 1-phenyl-3-methyl-4-benzoylpyrazolone-5 in freon 113

1980 ◽  
Vol 45 (4) ◽  
pp. 1221-1226 ◽  
Author(s):  
Oldřich Navrátil ◽  
Pavel Linhart
Keyword(s):  
Ionic Strength ◽  
Aqueous Solutions ◽  
Stability Constants ◽  
Aqueous Phase ◽  
Organic Phase ◽  
Extraction Constants ◽  
Distribution Constants ◽  
The Stability

The partition of 1-phenyl-3-methyl-4-benzoylpyrazolone-5 (HA) between aqueous solutions of HClO4 and NaClO4, ionic strength 0.1, and Freon 113 or its 2 : 1 mixture with benzene was studied. The logarithms of the HA distribution constants are 2.84 ± 0.10 and 3.39 ± 0.15 for the two organic phases, respectively. The extraction curves of cerium(III) and europium(III) revealed that in dependence on the pH of the aqueous phase, the metals are transferred into the organic phase in the form of the MA3 complexes (M = Ce, Eu). The stability constants of the complexes MAn in the aqueous phase were determined along with their distribution and extraction constants. For cobalt, zinc, and hafnium, a part of the extraction curves could only be studied, only the extraction constants were therefore determined. The sparing solubility of HA in Freon 113 can be circumvented by using a Freon-benzene mixture 2 : 1, which is still practically incombustible.

The Extraction Transfer of H+-18-Crown-6 Species across the Water-Nitrobenzene Phase Boundary in the Extraction of Aqueous Solutions of Perchloric Acid by Nitrobenzene in the Presence of 18-Crown-6

1993 ◽  
Vol 58 (3) ◽  
pp. 483-495 ◽  
Author(s):  
Petr Vaňura ◽  
Iveta Juklíková
Keyword(s):  
Experimental Data ◽  
Phase Boundary ◽  
Perchloric Acid ◽  
Free Enthalpy ◽  
Nitrobenzene Phase ◽  
Extraction Constants ◽  
L Systems ◽  
Individual Extraction Constants ◽  
The Individual ◽  
The Given

A study was made of the extraction of perchloric acid in water-nitrobenzene-18-crown-6 (hereafter L) systems. The experimental data was interpreted on the basis of the assumption that the extraction occurs according the equations H+aq + ClO4,aq- ↔ H+org + ClO4,org- and H+aq + Laq + ClO4,aq- ↔ HL+org + ClO4,org-. Crown is also protonated in the aqueous phase according to the equation H+aq + Laq ↔ HL+aq. The values of the corresponding extraction constants, the protonation constants of 18-crown-6 in nitrobenzene and water and the individual extraction constants of the HL+ species in the water-nitrobenzene system were determined, along with the magnitude of the molar free enthalpy for the transfer of these species across the given phase boundary.

FLUORIDE COMPLEXES OF GERMANIUM (IV) IN AQUEOUS SOLUTION

1963 ◽  
Vol 41 (5) ◽  
pp. 1170-1180 ◽  
Author(s):  
R. L. Benoit ◽  
J. Place
Keyword(s):  
Aqueous Solution ◽  
Solvent Extraction ◽  
Stability Constants ◽  
Perchloric Acid ◽  
Acid Media ◽  
Formation Curve ◽  
Maximum Value ◽  
Fluoride Complexes

The germanium (IV) – fluoride species in various acid media have been investigated by solvent extraction, solubility, and potentiometric methods. The results are interpreted in terms of a series of mononuclear fluorohydroxygermanium (IV) species in which the number of fluorides bound per germanium tends to a maximum value of 5. The formation curve in 0.50 M perchloric acid is explained in terms of stability constants of species [Formula: see text] and [Formula: see text]

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.

Distribution of dibenzyl sulfoxide between the aqueous and organic phases

1979 ◽  
Vol 44 (6) ◽  
pp. 1918-1924 ◽  
Author(s):  
František Vláčil ◽  
Huynh Dang Khanh
Keyword(s):  
Aqueous Solution ◽  
Nitric Acid ◽  
Perchloric Acid ◽  
Distribution Ratio ◽  
Protonation Constant ◽  
Metal Salts ◽  
Acid Solutions ◽  
Lower Solubility ◽  
Extraction Constants ◽  
Distribution Constants

The distribution of dibenzyl sulfoxide (DBSO) between toluene or tetrachloromethane and aqueous solution of nitric, hydrochloric, or perchloric acid was investigated for different acid concentrations. The solubility of DBSO in the two solvents was established (0.0555 mol l-1 in toluene, 0.0121 mol l-1 in tetrachloromethane at 20 °C) and its distribution constants KD were determined for the systems toluene-water and CCl4-water (133.7 and 27.4, respectively, at 20 °C). Employing the dependence of the distribution ratio of DBSO on the Hammett function for nitric and perchloric acids solutions (1-6M) and taking into account the extraction of the solvates of these acids as described previously, the value of the DBSO protonation constant was calculated to be KH1 (B + H+ ##e BH+) = 1.00 . 10-2, and more accurate values of the extraction constants of the nitric acid solvates were obtained, Kex1 (HNO3 . B) 1.1 . 10-3 and Kex2 ((HNO3)2 . B) 4.3 . 10-5. Owing to the lower solubility of DBSO in water as well as in acid solutions as compared with aliphatic or cyclic sulfoxides and also with tri-n-butylphosphate, solution of DBSO in toluene suits better as the stationary phase for extraction chromatography of metal salts.

Extraction of hafnium(IV) with organophosphorus reagents from solutions of mineral acids mixtures

1979 ◽  
Vol 44 (12) ◽  
pp. 3656-3664
Author(s):  
Oldřich Navrátil ◽  
Jiří Smola ◽  
Rostislav Kolouch
Keyword(s):  
Ionic Strength ◽  
Aqueous Phase ◽  
Organic Phase ◽  
Perchloric Acid ◽  
Synergic Effect ◽  
Salting Out ◽  
Initial Concentration ◽  
Mixed Complexes ◽  
Synergic Extraction ◽  
Mineral Acids

Extraction of hafnium(IV) was studied from solutions of mixtures of perchloric and nitric acids and of perchloric and hydrochloric acids for constant ionic strength, I = 2, 4, 6, or 8, and for cHf 4 . 10-4 mol l-1. The organic phase was constituted by solutions of some acidic or neutral organophosphorus reagents or of 2-thenoyltrifluoroacetone, 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone, or N-benzoyl-N-phenylhydroxylamine in benzene, chloroform, or n-octane. A pronounced synergic extraction of hafnium proceeds only on applying organophosphorus reagents from an aqueous phase whose acidity is not lower than 3M-(HClO4 + HNO3) or 5M-(HClO4 + HCl). The synergic effect was not affected markedly by a variation of the initial concentration of hafnium in the range 1 . 10-8 -4 .10-4 mol l-1, it lowered with increasing initial concentration of the organophosphorus reagent and decreasing concentration of the H+ ions. It is suggested that the hafnium passes into the organic phase in the form of mixed complexes, the salting-out effect of perchloric acid playing an appreciable part.

Extraction of strontium and barium salts by the nitrobenzene solution of dicarbolide in the presence of glymes

1985 ◽  
Vol 50 (3) ◽  
pp. 581-599 ◽  
Author(s):  
Petr Vaňura ◽  
Emanuel Makrlík
Keyword(s):  
Stability Constants ◽  
Organic Phase ◽  
Equilibrium Constants ◽  
Minor Role ◽  
Nitrobenzene Solution ◽  
Ligand Structure ◽  
Stability Constants Of Complexes ◽  
Separation Factors ◽  
The Stability ◽  
A Minor

Extraction of microamounts of Sr2+ and Ba2+ (henceforth M2+) from the aqueous solutions of perchloric acid (0.0125-1.02 mol/l) by means of the nitrobenzene solutions of dicarbolide (0.004-0.05 mol/l of H+{Co(C2B9H11)2}-) was studied in the presence of monoglyme (only Ba2+), diglyme, triglyme, and tetraglyme (CH3O-(CH2-CH2O)nCH3, where n = 1, 2, 3, 4). The distribution of glyme betweeen the aqueous and organic phases, the extraction of the protonized glyme molecule HL+ together with the extraction of M2+ ion and of the glyme complex with the M2+ ion, i.e., ML2+ (where L is the molecule of glyme), were found to be the dominating reactions in the systems under study. In the systems with tri- and tetraglymes the extraction of H+ and M2+ ions solvated with two glyme molecules, i.e., the formation of HL2+ and ML22+ species, can probably play a minor role. The values of the respective equilibrium constants, of the stability constants of complexes formed in the organic phase, and the theoretical separation factors αBa/Sr were determined. The effect of the ligand structure on the values of extraction and stability constants in the organic phase is discussed.

Europium and cerium extraction by the nitrobenzene solution of dicarbolide in the presence of polyethylene glycols

1986 ◽  
Vol 51 (3) ◽  
pp. 498-515 ◽  
Author(s):  
Emanuel Makrlík ◽  
Petr Vaňura
Keyword(s):  
Molecular Weight ◽  
Polyethylene Glycol ◽  
Organic Phase ◽  
Perchloric Acid ◽  
Equilibrium Constants ◽  
Polyethylene Glycols ◽  
Individual Species ◽  
Nitrobenzene Solution ◽  
Separation Factors ◽  
Equilibrium Data

Extraction of Eu3+ and Ce3+ microamounts from 0.1-0.4M perchloric acid by the nitrobenzene solution of dicarbolide H+[Co(C2B9H11)2]- in the presence of polyethylene glycols (Mr = 200, 300, 400) has been studied. The equilibrium data and the typical maxima on the dependence of the metal distribution ratio on the total analytical concentration of polyethylene glycol in the system can be explained assuming that the species ML3+org, ML3+2org, ML3+3org, MLH2+-1org, and HL+org (where M3+ = Eu3+, Ce3+; L = polyethylene glycol) are extracted into the organic phase. The values of extraction and equilibrium constants in the organic phase were determined and the effect of the polyethylene glycol molecular weight on the equilibrium constants and on the abundances of individual species in the organic phase is discussed. It has been found that the addition of polyethylene glycol to the acid - nitrobezene - dicarbolide system increases the values of the separation factors αCe/Eu.

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