EUROPIUM OXALATE ION ASSOCIATION IN WATER

1966 ◽  
Vol 44 (24) ◽  
pp. 3057-3062 ◽  
Author(s):  
P. G. Manning
Keyword(s):  
Acetic Acid ◽  
Ionic Strength ◽  
Stability Constant ◽  
Stability Constants ◽  
Aqueous Phase ◽  
Sodium Acetate ◽  
Ion Association ◽  
Sodium Oxalate ◽  
Aqueous Sodium ◽  
Oxalate Ion

The partitioning of radiotracer 152/151Eu between aqueous sodium oxalate (Na2L) solutions and toluene solutions of thenoyltrifluoroacetone (HTTA) has been studied as a function of the oxalate concentration. The pH of the aqueous phase was controlled by means of sodium acetate – acetic acid mixtures and the ionic strength (I) by NaCl or NaClO4.At low ionic strengths (~0.05) and [L] ~10−4 M EuL+ formed, but at I = 0.95 and [L] ~10−3 M EuL2− also formed. Stability constants for the 1:1 and 1:2 (metal:ligand) complexes are reported.The magnitudes of the stepwise stability constant ratios are discussed.

Europium tartronate and mandelate ion association in water

1967 ◽  
Vol 45 (14) ◽  
pp. 1643-1647 ◽  
Author(s):  
P. G. Manning
Keyword(s):  
Ionic Strength ◽  
Solvent Extraction ◽  
Stability Constant ◽  
Stability Constants ◽  
Ion Association ◽  
Tridentate Ligand ◽  
Radiotracer Method ◽  
The Stability ◽  
Two Stages ◽  
Low Ionic Strength

Stepwise stability constants have been determined for the 1:1 and 1:2 Eu3+:mandelate− and Eu3+:tartronate2− complexes in water. Measurements were made at low ionic strength and the temperature was 25 °C. The solvent-extraction–radiotracer method was used.For the mandelate system at an ionic strength of 0.104, K1 = 5.0 × 102, K2 = 1.58 × 102, and K1:K2 = 3.1. The K1:K2 ratios suggest monodentate ligandcy.The stepwise stability constants for the two stages of tartronate ion association are: K1 = 7.1 ( ± 15%) × 104 and K1K2 = 4.2 ( ± 5%) × 108. The magnitudes of the stability constants suggest that tartronate is a tridentate ligand. The stability constant ratios are discussed with reference to the ratios for piperidinedicarboxylate and iminodiacetate complexes.

scholarly journals SYNTHESIS AND STORAGE OF SINGLE PHENYLTIN COMPOUNDS SYNTHESIZED FROM ISOTOPICALLY ENRICHED TIN METAL

2009 ◽  
Vol 12 (17) ◽  
pp. 42-54
Author(s):  
Van Nguyen Dong ◽  
Wolfgang Frech ◽  
Solomon Tesfalidet
Keyword(s):  
Acetic Acid ◽  
Ionic Strength ◽  
Aqueous Phase ◽  
Sodium Acetate ◽  
Single Species ◽  
Liquid Extraction ◽  
Liquid Liquid Extraction ◽  
Tin Metal ◽  
And Storage ◽  
Better Than

A method combining liquid liquid extraction and chromatographic fractionation has been developed for the preparation of pure monophenyltin (MPT), diphenyltin (DPhT), and triphenyltin (TPhT), synthesized from isotope enriched Sn-metal using phenylation of SnI4 in diethylether (DEE) followed by quenching with HBr and water. After two successive extractions of the aqueous HBr phase with DEE, more than 99% of the DPT and TPhT were recovered in the combined DEE phase and 94% of the MPT remained in the aqueous phase. The MPT in the aqueous phase was extracted into dichloromethane. The organic phases were vaporised and the PhTs were re-dissolved in MeOH/water/acetic acid/sodium acetate (59/30/6/8, v/v/v/w), which was also used as storing solution. Aliquots of the two solutions containing either DPhT and TPhT or MPhT were injected into a silica based C18 column for isolating and purifying single species. The yield of the purification of MPhT, DPT, and TPht was better than 99%. At -20 °C, all the fractionated phenyltin species were stable in the storing solution for at least 197 days. When these standards were stored at 4 °C or 22°C, 4% to 6% of DPhT and TPhT degraded during 27 days. The degradation of DPT and TPht increased with the ionic strength and acidity of the storage solution.

scholarly journals Partition of porphyrins between cyclohexanone and aqueous sodium acetate as a function of pH. Determination of uroporphyrin and of hydrophilic porphyrin conjugates

1967 ◽  
Vol 105 (3) ◽  
pp. 1085-1090 ◽  
Author(s):  
C. Rimington ◽  
A. Benson
Keyword(s):  
Aqueous Phase ◽  
Sodium Acetate ◽  
Second Step ◽  
Aqueous Sodium ◽  
Variegate Porphyria ◽  
Model Experiments ◽  
Peptide Fraction

1. The partition of uroporphyrins I and III, coproporphyrins I and III, haematoporphyrin IX, porphyrin c and a hydrophilic porphyrin–peptide fraction from variegate-porphyria faeces has been studied in systems of equal volumes of cyclohexanone and sodium acetate buffers of varying pH and concentration. 2. The concentration of acetate in the aqueous phase has little effect on the partition of porphyrin c, but markedly influences that of uroporphyrin. At 50% acetate saturation and pH4·5, only 5% enters the cyclohexanone phase whereas 60% of porphyrin c is extracted under similar conditions. 3. This circumstance forms the basis of a method for the determination of hydrophilic porphyrin–peptides in variegate-porphyria urine. Its reliability has been checked in model experiments. 4. At pH1·5 and an aqueous phase half-saturated with sodium acetate, an equal volume of cyclohexanone removes 95–97% of uroporphyrin and about 55% of porphyrin c. Uroporphyrin may therefore be determined as a second step in the method. 5. For the routine determination of uroporphyrin in systems free from other hydrophilic porphyrins, cyclohexanone extraction may be performed at any pH in the range 1·0–3·0.

Thermodynamic modeling of metal-ligand interactions in high ionic strength NaCl solutions: the Co2+-oxalate system

2000 ◽  
Vol 88 (9-11) ◽  
Author(s):  
M. Borkowski ◽  
Gregory R. Choppin ◽  
Robert C. Moore
Keyword(s):  
Ionic Strength ◽  
Solvent Extraction ◽  
Stability Constant ◽  
Aqueous Solutions ◽  
High Ionic Strength ◽  
Pitzer Equations ◽  
Ligand Interactions ◽  
Oxalate Ion ◽  
Apparent Stability ◽  
Metal Ligand

First and second apparent stability constants for cobalt(II) with oxalate ion have been determined using solvent extraction. Data were collected in 0.3 m to 5.0 m NaCl aqueous solutions. The logarithms of first stability constant ranged from 3.30 ± 0.03 to 3.57 ± 0.03 and second stability constant ranged from 5.49 ± 0.05 to 6.02 ± 0.06. The data were modeled using the Pitzer equations. For the 1:1 complex, values of the μ

Study of the main extracted species of cobalt(II) ion with dodecylthioglycolic acid as extractor

1986 ◽  
Vol 64 (1) ◽  
pp. 15-18 ◽  
Author(s):  
P. Beneitez ◽  
S. J. Ortiz ◽  
J. Ortega
Keyword(s):  
Acetic Acid ◽  
Ionic Strength ◽  
Sodium Nitrate ◽  
Thermal Gravimetric Analysis ◽  
Sodium Acetate ◽  
Aqueous Media ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
Buffer Solutions ◽  
Organic Extractant

The distribution of cobalt(II) between water and an organic extractant (dodecylthioglycolic acid) dissolved in kerosene has been studied using a tracer of 60Co. The aqueous media wee always constituted by buffer solutions (acetic acid – sodium acetate) and the ionic strength was adjusted with sodium nitrate to 1 mol dm−3. The main species of cobalt(II) originating in the organic phase has been isolated and characterized on the basis of elemental analysis, thermal gravimetric analysis, and ir spectra.

Equilibria in Acetic Acid: Ion Association Constants of Salts and the Autoprotolysis Constant of Acetic Acid at 105.7°C

1962 ◽  
Vol 15 (3) ◽  
pp. 409 ◽  
Author(s):  
RJL Martin
Keyword(s):  
Acetic Acid ◽  
Perchloric Acid ◽  
Sodium Acetate ◽  
Specific Conductivity ◽  
Ion Pairs ◽  
Sodium Perchlorate ◽  
Ion Association ◽  
Association Constants ◽  
Ion Association Constants

The ion association constants KA=[M+A-]/[M+][A-] which have been measured conductimetrically at 105 7 �C in acetic acid are : perchloric acid 0.0644 X 106, sodium perchlorate 0.1346 x 106, and sodium acetate 0.752 x 106. The parameters 6, centre to centre distance between the ions at contact, which were calculated from Bjerrum's formula, are : perchloric acid 4.52 Ǻ, sodium perchlorate 4.20 Ǻ, and sodium acetate 3.61 Ǻ. The autoprotolysis constant, K = [H2+ Ac][Ac-]= 1.17 x 10-19, was calculated from the specific conductivity of acetic acid at 105.7 �C. The acetic acidium acetate ion pairs were calculated to be 100.0% dissociated.

TARTRATE COMPLEXES OF THE RARE-EARTH ELEMENTS: I. THE d-, dl-, AND meso-TARTRATE COMPLEXES OF Tb AND Eu

1963 ◽  
Vol 41 (10) ◽  
pp. 2557-2565 ◽  
Author(s):  
P. G. Manning
Keyword(s):  
Rare Earth ◽  
Ionic Strength ◽  
Sodium Perchlorate ◽  
Ion Association ◽  
Complex Species ◽  
Sodium Tartrate ◽  
Aqueous Sodium ◽  
Coordination Numbers ◽  
Trace Concentrations ◽  
Radiotracer Techniques

Solvent extraction and radiotracer techniques have been applied to the study of metal – tartrate ion association in water at 25 °C. Trace concentrations of the radioisotopes Tb160 and Eu152/154 were equilibrated between aqueous sodium tartrate solutions and organic phases of thenoyltrifluoroacetone in toluene. The ionic strength (0.0597) and the pH (4.53) of the aqueous phase were kept constant by means of sodium perchlorate and sodium acetate.Metal complexing with the d-, dl-, and meso isomers of the ligand was examined. For all isomers two complex species were identified with metal:ligand ratios of 1:1 and 1:2, and stability constants for both stages of ion association have been estimated. No third (1:3) complex was detected.Metal coordination numbers and the formation of tartrate–tartrate hydrogen bridges in the 1:2 complex are discussed.

scholarly journals Activity corrections for ionic equilibria in aqueous solutions

1980 ◽  
Vol 58 (12) ◽  
pp. 1253-1257 ◽  
Author(s):  
Mian S. Sun ◽  
Donald K. Harriss ◽  
Vincent R. Magnuson
Keyword(s):  
Ionic Strength ◽  
Stability Constant ◽  
Aqueous Solutions ◽  
General Formula ◽  
Stability Constants ◽  
Ionic Equilibria ◽  
Ion Activity ◽  
The Difference ◽  
Single Ion Activity ◽  
The Stability

Activity corrections for ionic equilibria in aqueous solutions at 25 °C and ionic strengths up to 0.5 have been investigated. An empirical formula for activity corrections was generated by statistically fitting stability constant data for approximately 540 complexes, for which both thermodynamic and concentration stability constants were known, to a modified Debye – Hückel relationship. The general formula is[Formula: see text]χ > 0, where Δ log K is the difference in the logarithms of the stability constants at infinite dilution and finite I (I ≤ 0.5), and χ is an even integer dependent only on the stoichiometry and charge of the ions involved. Activity correction formulae for ionic equilibria involving classes of ligands (amino acid, inorganic, amine, and organic acid) also were developed. The general formula predicts stability constant corrections within 0.1 log unit for 87 % of the data used at ionic strength 0.1 and 64 % of the data at ionic strength 0.5. In addition, single ion activity coefficients as a function of ionic strength, 0 < I ≤ 0.5, are presented.

scholarly journals Methylene blue adsorption onto modified lignin from sugar cane bagasse

2007 ◽  
Vol 32 (4) ◽  
pp. 63-70 ◽  
Author(s):  
N. Consolin Filho ◽  
E. C. Venancio ◽  
M. F. Barriquello ◽  
A. A. W. Hechenleitner ◽  
E. A. G. Pineda
Keyword(s):  
Methylene Blue ◽  
Acetic Acid ◽  
Ionic Strength ◽  
Sugar Cane ◽  
Sodium Acetate ◽  
Adsorption Process ◽  
Sugar Cane Bagasse ◽  
Langmuir Model ◽  
Mechanical Stirring ◽  
Modified Lignin

The adsorption kinetics and equilibrium of methylene blue (MB) onto reticulated formic lignin (RFL) from sugar cane bagasse was studied. The adsorption process is pH, temperature and ionic strength (µ) dependent and obeys the Langmuir model. Conditions for higher adsorption rate and capacity were determined. The faster adsorption (12 hours) and higher adsorption capacity (34.20 mg.g-1) were observed at pH = 5.8 (acetic acid-sodium acetate aqueous buffer), 50 ºC and 0.1 ionic strength. Under temperature (50 ºC) control and occasional mechanical stirring it took from 1 to 10 days to reach the equilibrium.

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.

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