Principles of Extraction of Electrolytes

Rais, J.

doi:10.1201/9780203027301.ch6

Cited by 9 publications

(7 citation statements)

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“…Finally, the intercept of the linear correlation represents the value of the conditional equilibrium constant, log K 2 0 ¼ 2.84 + 0.01, which is in very good agreement with the value of log K 2 ¼ 2.85 + 0.02 obtained in the less rigorous approach. In general, the treatment of Cs distribution data in accord with equilibrium (2) and Equation (9) is an appropriate simplification as indicated by the reasonable agreement and excellent correlation presented in Fig. 4, provided the [HCCD] !…”

Section: R S Herbst Et Almentioning

confidence: 79%

“…The contribution of dissociated species, reasonably thought to occur at low concentrations of HCCD, is expected to be small or even negligible at higher concentrations of HCCD. The simplifications of neglecting Cs extraction by FS-13 alone and the formation of dissociated species in the organic phase reduce the model to the single equilibrium indicated by equation (2). It was possible to model those experimental data collected for [HCCD] !0.0005 M (0.5 mM) in this manner; however, equilibrium (9) did a poor job of predicting those Cs distribution data collected at concentrations of 10 24 M HCCD (data sets 6 and 7).…”

Section: R S Herbst Et Almentioning

confidence: 99%

“…Many of these development efforts are adequately described and reviewed in the recent literature. [2,3] In an earlier communication, [4] the present authors proposed a model of Cs extraction by the hexachlorinated derivative of the chloro-protected cobalt bis(dicarbollide) anion [ (8, 9, 12-Cl 3 -C 2 B 9 H 8 ) 2 -3-Co] 2 in the protonated form (HCCD) and dissolved in the polar diluent trifluoromethylphenyl sulfone (FS-13). Therein, several data sets of Cs distribution ratios, D Cs ; [Cs] org /[Cs] aq , at a variety of initial conditions (various concentrations of [HCCD] and [HNO 3 ]) were modeled using the SXLSQI computer program developed at Oak Ridge National Laboratory (ORNL).…”

Section: Introductionmentioning

confidence: 99%

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Fundamental Chemistry of Cesium Extraction from Acidic Media by HCCD in FS‐13

Herbst

Peterman

Tillotson

et al. 2008

Solvent Extraction and Ion Exchange

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We previously published a model for cesium extraction from acidic media by the protonated form of the hexachlorinated derivative of the chloro-protected cobalt bis(dicarbollide), HCCD, dissolved in trifluoromethylphenyl sulfone, FS-13. The model indicated that Cs extraction proceeds through a series of ion-paired and/or dissociated extraction equilibria. Additional Cs distribution ratio data has been obtained and the model refined and simplified. It is demonstrated that the equilibrium exclusively involving the exchange of proton for cesium by formation of ion-paired CsCCD models the Cs distribution data very well, particularly for the concentrations of HCCD greater than 0.0005 M (0.5 mM). Finally, activity corrections for the aqueous phase to the Cs distribution data results in good agreement to the theoretical value of 21 for slope (log-log) analysis of the data over a wide range of HNO 3 and HCCD concentrations.

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Section: R S Herbst Et Almentioning

confidence: 79%

Section: R S Herbst Et Almentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Fundamental Chemistry of Cesium Extraction from Acidic Media by HCCD in FS‐13

Herbst

Peterman

Tillotson

et al. 2008

Solvent Extraction and Ion Exchange

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“…It concerns the chlorinated cobalt bis(dicarbollide) CCD 2 anions which are known to display high synergistic effects in liquid-liquid extraction of metallic cations. [45] In spite of their "ellipsoidal" shape, they are surface active and concentrate at the "oil"-water interface, with marked counterions effects, when the Cs þ , H 3 O þ , UO 2 2þ , and Eu 3þ salts of CCD 2 are compared. [44] When simulated in water, as well as in chloroform, these CCD 2 ions have been found to aggregate, [44] thus displaying analogies with the simulated cryptates.…”

Section: Discussionmentioning

confidence: 99%

Supramolecular Interactions of Cryptates in Concentrated Solutions: The Effect of Solvent and Counterions Investigated by MD Simulations

Jost¹,

Galand²,

Schurhammer³

et al. 2007

Solvent Extraction and Ion Exchange

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We present a molecular dynamics study of concentrated solutions of K þ , 222 cryptates, comparing two counterions X 2 (Chloride Cl 2 versus Picrate Pic 2) and three solvents (water, acetonitrile, and chloroform), with the main aim to investigate the distribution of the ions in the different solutions. The simulations reveal marked differences from one system to the other. In acetonitrile, with either Cl 2 or Pic 2 counterions, the cryptates and the X 2 anions are well diluted in the solvent box, without revealing specific ion pairing. In the less polar chloroform solutions, the complexes aggregate, and aggregation is more pronounced with Cl 2 than with Pic 2 counterions. In water, hydrophobic forces lead to still different anion dependent arrangements. The hydrophilic Cl 2 anions are diluted in water, without pairing with the cryptates which tend to "attract each other," in spite of their coulombic repulsions. The Pic 2 anions are more hydrophobic than Cl 2 and display p2stacking attractions, forming negatively charged oligomers surrounded by cryptates that are therefore close to each other. The role of counterion is further demonstrated with aqueous solutions of the more charged Ba 2þ , 222 cryptates, comparing the Cl 2 to the Pic 2 counterions. Beyond the case of the studied model solutions, the results have a bearing on the aggregation phenomena of other big ions (e.g. cation complexes, or bulky anions like polyoxometallates, or carborane derivatives) in solution.

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“…More formally, SHG originates from a nonlinear polarization P (2) oscillating at the harmonic frequency 2ω which is related to the fundamental electric field E(ω): (1) where χ (2) ijk is the quadratic susceptibility tensor in the i,j,k Cartesian coordinates. The components of this tensor depend on the hyperpolarisability of the molecules, an intrinsic feature related to the molecular geometry and electronic structure.…”

Section: Introductionmentioning

confidence: 99%

Surface Activity and Molecular Organization of Metallacarboranes at the Air–Water Interface Revealed by Nonlinear Optics

et al. 2015

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Because of their amphiphilic structure, surfactants adsorb at the water-air interface with their hydrophobic tails pointing out of the water and their polar heads plunging into the liquid phase. Unlike classical surfactants, metallabisdicarbollides (MCs) do not have a well-defined amphiphilic structure. They are nanometer-sized inorganic anions with an ellipsoidal shape composed of two carborane semicages sandwiching a metal ion. However, MCs have been shown to share many properties with surfactants, such as self-assembly in water (formation of micelles and vesicles), formation of lamellar lyotropic phases, and surface activity. By combining second harmonic generation and surface tension measurement, we show here that cobaltabis(dicarbollide) anion {[(C2B9H11)2Co](-) also named [COSAN](-)} with H(+) as a counterion, the most representative metallacarborane, adsorbs vertically at the water surface with its long axis normal to the surface. This vertical molecular orientation facilitates the formation of intermolecular and nonconventional dihydrogen bonds such as the B-H(δ-)···(δ+)H-C bond that has recently been proven to be at the origin of the self-assembly of MCs in water. Therefore, it appears here that lateral dihydrogen bonds are also involved in the surface activity of MCs.

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Principles of Extraction of Electrolytes

Cited by 9 publications

References 0 publications

Fundamental Chemistry of Cesium Extraction from Acidic Media by HCCD in FS‐13

Fundamental Chemistry of Cesium Extraction from Acidic Media by HCCD in FS‐13

Supramolecular Interactions of Cryptates in Concentrated Solutions: The Effect of Solvent and Counterions Investigated by MD Simulations

Surface Activity and Molecular Organization of Metallacarboranes at the Air–Water Interface Revealed by Nonlinear Optics

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