The mechanism of extraction of zinc(II) from aqueous chloride solutions into chloroform solutions of methyltrioctylammonium chloride

1982 ◽  
Vol 35 (6) ◽  
pp. 1095 ◽  
Author(s):  
H Daud ◽  
RW Cattrall
Keyword(s):  
Organic Phase ◽  
Equilibrium Constants ◽  
Full Range ◽  
Single Drop ◽  
Exchange Reactions ◽  
Extraction Equilibrium ◽  
Rate Determining Step ◽  
Aqueous Chloride ◽  
Fast Ion ◽  
Drop Technique

The mechanism of the transfer of zinc(11) between 1.0 M HCl, 6.0 M HCl and 6.0 M LiCl and methyltrioctylammonium chloride in chloroform has been studied by using the single-drop technique. It is suggested that interfacial complexes are formed by fast ion-exchange reactions and that the rate-determining step, in the case of 1.0 M HCl and 6.0 M LiCl, involves the replacement at the interface of the complex R2ZnCl4 by two molecules of reagent from the bulk organic phase. For 6.0 M HCl the rate-determining step is the replacement of the interfacial complex RHZnCl4 by one molecule of reagent from the bulk organic phase. Support for this mechanism is obtained by comparing the extraction equilibrium constants for the complex R2ZnCl4 for 1.0 M HCl and 6.0 M LiCl from previous with the values calculated from the rate data. Interfacial tension measurements have shown that the interface is saturated with reagent over the full range of concentrations studied.

The mechanism of extraction of iron(III) from 6 M hydrochloric acid by long chain amines in chloroform

1983 ◽  
Vol 36 (7) ◽  
pp. 1319 ◽  
Author(s):  
MZ Ilic ◽  
RW Cattrall ◽  
DE Davey
Keyword(s):  
Organic Phase ◽  
Equilibrium Constants ◽  
Single Drop ◽  
Two Phase ◽  
Extraction Equilibrium ◽  
Rate Determining Step ◽  
Fast Reactions ◽  
Complex Forms ◽  
Fast Ion ◽  
Drop Technique

The mechanism of transfer of FellI between 6.0 M HCl and five amine chlorides in chloroform has been studied by means of the single-drop technique. It is suggested that the (1,1) complex forms at the interface by fast ion-exchange and that the rate determining step involves the replacement of the complex at the interface by one molecule of reagent monomer from the bulk organic phase. Additional heterogeneous aggregates are formed in the bulk organic phase by fast reactions with reagent monomer. Support for this mechanism is obtained through the excellent agreement between the extraction equilibrium constants calculated from the rate data for the (1,1) complexes and the values obtained previously by two phase titration studies.

The extraction of cobalt(II) from lithium chloride solutions by aliquat 336R dissolved in chloroform

1982 ◽  
Vol 35 (11) ◽  
pp. 2345 ◽  
Author(s):  
R Paimin ◽  
RW Cattrall
Keyword(s):  
Ion Exchange ◽  
Aqueous Phase ◽  
Lithium Chloride ◽  
Organic Phase ◽  
Equilibrium Constants ◽  
Single Drop ◽  
Chloride Solutions ◽  
Rate Determining Step ◽  
Fast Ion ◽  
Drop Technique

The extraction of cobalt(II) by Aliquat 336R from 7 M lithium chloride solutions involves two species from the aqueous phase, COCl42 and CoCl3-, with the former being the predominant one. The equilibrium constants for the formation of the extracted complexes (R3MeN+)2 CoCl42- and R3MeN+CoCI3- are: logKll 5.01 and logK12 9.55. From the results of experiments by means of the single-drop technique, a mechanism is proposed based on the formation of interfacial complexes by fast ion-exchange with a rate-determining step which involves the replacement at the interface of the complex (R3MeN+)2 COCl42- by two molar proportions of reagent from the bulk organic phase.

scholarly journals Liquid-Liquid Extraction of Transition Metal Cations by Glyoximes and Their Macrocyclic Glyoxime Ether Derivatives

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Nazan Karapinar ◽  
Emin Karapinar ◽  
Emine Ozcan
Keyword(s):  
Transition Metal ◽  
Transition Metals ◽  
Crown Ether ◽  
Aqueous Phase ◽  
Organic Phase ◽  
Equilibrium Constants ◽  
Liquid Extraction ◽  
Extraction Equilibrium ◽  
Liquid Liquid Extraction ◽  
Extraction Constants

Liquid-liquid extraction of various alkalis (Li+, Na+, K+, and Cs+), transition metals (Co2+, Ni2+, Cu2+, Zn2+, Cd2+, and Hg2+), and Pb2+cations with phenylglyoxime (L1), p-tolylglyoxime (L2),N′-(4′-Benzo[15-crown-5])phenylaminoglyoxime (L3), andN′-(4′-Benzo[15-crown-5])-p-tolylaminoglyoxime (L4) from the aqueous phase into the organic phase was carried out. For comparison, the corresponding two glyoximes and their macrocyclic glyoxime ether derivatives were also examined. Crown ether groups having ligands (L3,L4) carry especially Na+cation from aqueous phase to organic phase. The extraction equilibrium constants (Kex) for complexes of ligands with Cu2+and Hg2+metal picrates between dichloromethane and water have been determined at 25°C. The values of the extraction constants (logKex) were determined to be 12.27, 13.37, 12.94, and 12.39 for Cu2+and 10.29, 10.62, 11.53, and 11.97 for Hg2+with L1–L4, respectively.

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.

scholarly journals Comparative Extraction of Aluminum Group Metals Using Acetic Acid Derivatives with Three Different-Sized Frameworks for Coordination

Separations ◽  
2021 ◽  
Vol 8 (11) ◽  
pp. 211
Author(s):  
Keisuke Ohto ◽  
Nako Fuchiwaki ◽  
Hiroaki Furugou ◽  
Shintaro Morisada ◽  
Hidetaka Kawakita ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Metal Ions ◽  
Spectroscopic Data ◽  
Equilibrium Constants ◽  
Structural Effects ◽  
Extraction Equilibrium ◽  
Ph Values ◽  
Slope Analysis ◽  
Coordination Sites ◽  
Extraction Properties

We prepared acetic acid derivatives using three different frameworks, calix[4]arene, alkenyltrimethylol, and trihydroxytriphenylmethane, which differ in the number and size of their coordination sites. We further investigated the extraction properties for aluminum group metal ions. All three extraction reagents exhibited increased extraction compared with the corresponding monomeric compounds, owing to structural effects. The extraction reaction and extraction equilibrium constants were determined using a slope analysis. Their extraction abilities, separation efficiencies, and potential coordination modes are discussed using the extraction equilibrium constants, half-pH values, and spectroscopic data. The calix[4]arene and trihydroxytriphenylmethane derivatives demonstrated allosteric co-extraction of indium ions (In3+) with an unexpected stoichiometry of 1:2.

scholarly journals Solvent extraction of Sc(III) from sulfuric acid solution by bis(2-ethylhexyl) phosphonic acid in toluene

2002 ◽  
Vol 67 (4) ◽  
pp. 265-272 ◽  
Author(s):  
Devendra Koladkar ◽  
Purshottam Dhadke
Keyword(s):  
Sulfuric Acid ◽  
Acid Solution ◽  
Sulfuric Acid Solution ◽  
Equilibrium Constants ◽  
Phosphinic Acid ◽  
Extraction Equilibrium ◽  
H2so4 Concentration ◽  
Liquid Liquid Extraction ◽  
Extraction Reaction ◽  
Reaction Proceeds

Liquid-liquid extraction of scandium(III) from sulfuric acid solution using bis(2-ethylhexyl) phosphinic acid (PIA-8) in toluene has been studied. The extraction of scandium(III) was found to be quantitative with 0.03 M PIA-8 in toluene in the acidic range of 0.1?0.5 M and 6.0?8.0 M H2SO4. The effect of the reagent concentration and other parameters on the extraction of scandium(III) was also studied. The stoichiometry of the extracted species of scandium(III) was determined on the basis of the slope analysis method. The extraction reaction proceeds via the cation exchange mechanism in the H2SO4 concentration range of 0.1?0.5M and the extracted species is ScR3.3HR. However, at higher acidity (6.0M?8.0M H2SO4) it proceeds by solvation. The extracted species is HSc(SO4)2.4HR. The temperature dependencies of the extraction equilibrium constants were examined to estimate the apparent thermodynamic functions (?H, ?S and ?G) for the extraction reaction.

scholarly journals Equilibrium Modeling of Astaxanthin Extraction from Haematococcus pluvialis

2021 ◽  
Vol 21 (3) ◽  
pp. 554
Author(s):  
Putri Restu Dewati ◽  
Rochmadi Rochmadi ◽  
Abdul Rohman ◽  
Avido Yuliestyan ◽  
Arief Budiman
Keyword(s):  
Experimental Data ◽  
High Performance ◽  
Haematococcus Pluvialis ◽  
Equilibrium Constants ◽  
Extraction Methods ◽  
Single Step ◽  
Equilibrium Models ◽  
Extraction Equilibrium ◽  
Assisted Extraction ◽  
Solid Liquid

Astaxanthin is a natural antioxidant, and the highest content of this compound is found in Haematococcus pluvialis microalgae. Microwave-assisted extraction (MAE) is one of the environmentally friendly extraction methods and has many advantages. This study aims to investigate the extraction of astaxanthin through the MAE method using various solvents. Several equilibrium models were proposed to describe this solid-liquid equilibrium. The solid-liquid extraction equilibrium parameters were determined by minimizing the sum of squares of errors (SSE), in which equilibrium constants were needed for scaling up purposes. Previously, the microalgae were pretreated with HCl to soften their cell walls in order to improve the extraction recovery. In this study, dichloromethane, acetone, methanol, and ethanol were used as the solvents for extraction. The astaxanthin concentration was determined by high-performance liquid chromatography (HPLC) and spectrophotometry. Astaxanthin was found to attain equilibrium at 57.42% recovery in a single-step extraction. Thus, several steps were required in sequence to obtain an optimum recovery. The experimental data were fitted to three equilibrium models, namely, Henry, Freundlich, and Langmuir models. The experimental data were well fitted to all the models for the extraction in dichloromethane, methanol, ethanol and acetone, as evident from the almost same SSE value for each model.

Solvent extraction studies of the system 64Cu/Htta/topo and the role of the metal complexes involved

1970 ◽  
Vol 23 (12) ◽  
pp. 2413
Author(s):  
EB Jacobs ◽  
WR Walker
Keyword(s):  
Solvent Extraction ◽  
Metal Complexes ◽  
Organic Phase ◽  
Ternary Complex ◽  
Equilibrium Constants ◽  
Synergistic Extraction ◽  
Back Extraction

Solvent extraction studies have been carried out on the system Cu/Htta/topo (Htta = thenoyltrifluoroacetone; topo = tri-n-octylphosphine oxide) with benzene as the organic phase. Using 64Cu as a tracer, equilibrium constants have been evaluated and compared with data obtained from the back-extraction of the labelled ternary complex 64Cu(tta)2(topo). The solubilities of binary and secondary complexes that are involved in synergistic extraction have also been measured.

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