Liquid-liquid distribution behavior of quaternary ammonium salts

Motomizu, Shoji; HAMADA, Shoichi; Tôei, Kyoji

doi:10.2116/bunsekikagaku.32.11_648

Cited by 23 publications

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“…Such a plot (not shown) is linear with zero intercept and a correlation coefficient r = 0.985. Its slope is (2.1 2 0.2) X lo6, which agrees with the literature value of KIP = 1 x lo6 predicted for QBr (21 obtained in this work can be used in the study of interfacial adsorption, as described below, because the method of measuring the concentration of quaternary ammonium in the chloroform phase is species-independent.…”

Section: Distribution Of Q B Rsupporting

confidence: 90%

Adsorption of tetrahexylammonium – bromothymol blue ion-pairs at the chloroform–water interface

Amankwa¹,

Cantwell²

1991

Can. J. Chem.

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LAWRENCE AMANKWA and FREDERICK F. CANTWELL. Can. J. Chem. 69, 88 (1991) Porous membrane phase separators are used to study the adsorption of the cation tetrahexylammonium (Qt), of the anion bromothymol blue (HB-) and of the ion-pair formed between them (QHB) at the liquid-liquid interface in a rapidly stirred mixture of chloroform and aqueous buffer. Adsorption isotherms in all three cases follow the Langmuir equation. The anion HBis much more strongly adsorbed than the ion-pair QHB. The porous membrane technique readily permits measurement of simultaneous adsorption of the two species HB-and QHB, and thereby allows a study of their competitive adsorption. When QHB is adsorbed in the presence of an excess of HB-both the saturated (monolayer) interfacial concentration of QHB and the logarithm of the adsorption equilibrium constant for QHB decrease linearly with an increase in interfacial concentration of HB-. This shows quantitatively that coadsorption of QHB and HB-involves a direct competition for space at the interface and also that the presence of adsorbed HB-changes the adsorbent properties of the interface. Analytical implications for solvent extraction are discussed. Solvent extraction of ion-pairs has been (1) and remains (2,3) an important technique for the analytical determination of ionic species. The equilibrium aspects of the distribution of ion-pairs between two bulk liquid phases have been extensively studied (1,4) and, more recently, the kinetic aspects of ion-pair extraction between bulk liquid phases have been investigated (5).Depending on the surface-activity of the sample ion, of the reagent ion and of the ion-pair formed between them, interfacial adsorption may play a major role in determining both the equilibrium and kinetic extraction behavior of ion-pairs. The use of porous membrane phase separators makes possible measurement of the amount of solute adsorbed at the liquidliquid interface in a vigorously stirred solvent extraction system and therefore permits the measurement of adsorption isotherms of solutes between the interface and the bulk liquid phases (6-9). Adsorption isotherms previously have been measured by this technique for interfacial adsorption of ion-pairs formed between cationic metal-ligand complexes and simple anions (10) and for the ion-pair tetrahexylammoniumpicrate (QP) (1 1). Because the technique allows measurement of concentrations in both liquid phases it makes possible the discrimination of two species simultaneously adsorbed at the interface. This is an advantage over conventional techniques for measuring interfacial adsorption such as those based on interfacial tension or pressure. This advantage is utilized in studying the tetrahexylammonium-bromothymol blue system. 'TO whom correspondence should be addressed.Bromothymol blue is one of the most often used anionic reagents for ion-pair extraction (I). In the present study bromothymol blue anion, HB-, which is surface-active, is used to form a surface-active ion pair, QHB, with tetrahexylammonium cation, Q + , w...

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Section: Distribution Of Q B Rsupporting

confidence: 90%

Adsorption of tetrahexylammonium – bromothymol blue ion-pairs at the chloroform–water interface

Amankwa¹,

Cantwell²

1991

Can. J. Chem.

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“…The values of ∆log Kex/-CH 2-for hexachloroantimonate(V) are in good agreement with the previously reported values. [13][14][15][16][17][18][19][26][27][28][29][30][31][32] Among the ion associates examined, the extractability values of the extracting solvent were in the order chloroform > benzene > toluene > carbon tetrachloride, which agrees with the order of the value of the transition energy as a parameter of polarity of the extracting solvent; the difference in the log Kex between two successive solvents in this order was about 0.52, 0.41 and 0.13 on the average.…”

Section: The Extracting Solventmentioning

confidence: 74%

Solvent Extraction of Antimony(V) as Hexachloroantimonate(V) with Quaternary Ammonium Ions

Yamamoto

Shimakawa

2000

ANAL. SCI.

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The extraction of antimony from an aqueous halide medium into an organic solvent has been frequently used for both the separation and spectrophotometric determination of antimony. The methods for the solvent extraction-photometric determination of antimony(V) based on the extraction of the ion-association complexes of the chloride-complex (SbCl6 -) of antimony(V) with cations of some dyes, such as Malachite Green, 1 Brilliant Green, 1-4 Crystal Violet, 1,2,5 Ethyl Violet 2 and Rhodamine B [6][7][8][9][10][11][12] have been reported. However, the equilibrium for the solvent extraction of the ion associates of hexachloroantimonate(V) has not been studied.In the present work, the extraction constants (log Kex) for the ion associates of hexachloroantimonate(V) ion with various quaternary ammonium ions distributed between an aqueous and four organic phases (chloroform, benzene, toluene and carbon tetrachloride) were determined and correlated with the number of carbon atoms in the quaternary ammonium ions. The extractability of hexachloroantimonate(V) was also considered based on those of other metal-halogeno complex anions. [13][14][15][16][17][18] Experimental ApparatusThe apparatus for recording spectra and absorbance measurements, horizontal shaking and phase separation after extraction were described in a previous paper. 19 ReagentsThe supplier and purity of quaternary ammonium ions, and the preparation of the quaternary ammonium ion solutions were as described in a previous paper. 15A standard antimony(III) solution (4 × 10 -4 M) was prepared by dissolving antimony(III) chloride with 8 M hydrochloric acid solution. Hydrochloric acid was used for the formation of a antimony(V)-chloro complex. Cerium(IV) sulfate solution was prepared by dissolving with a diluted sulfuric acid solution, and was employed as the oxidant for the oxidation of Sb(III) to Sb(V). A hydroxylammonium chloride aqueous solution was employed as the reductant for the reduction of any excess cerium(IV) sulfate. Commercially available chloroform, benzene, toluene and carbon tetrachloride were used without further purification, and were saturated with distilled water before use. Standard procedure for a stoichiometry measurementOne milliliter of a 4 × 10 -4 M antimony(III) solution was transferred to a 25 ml stoppered test-tube; then, 0.5 ml of a 9.44 M hydrochloric acid solution, 0.5 ml of a 2 × 10 -2 M cerium (IV) sulfate solution (in 6 M sulfuric acid), 1 ml of a 15 M sulfuric acid solution, 2 ml of concentrated hydrochloric acid solution, 0.5 ml of a 0.2 M hydroxylammonium solution and an appropriate amount of aqueous quaternary ammonium salt solution were added. The solution was diluted to 6 ml with distilled water. The aqueous solution was mechanically shaken with 6 ml of an extracting solvent for 20 min at 25˚C. After centrifugation of the mixture, the absorbance at 280 nm of the aqueous phase was measured for the determination of antimony. Calculation of the extraction constantsIn the chloride-ion concentration of 6 M, the antimony(V)-chl...

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“…The difference in log KD between phenol and 2-naphthol is 1.47, which is in good agreement with the value obtained from ion association extraction (1.53). 6 The substituent constants of the hydroxyl and carboxyl groups were obtained with 1-octanol by Hansch et al: 7COH=-0.67 and 7T000H=-0.32. 3 The difference in log KD between phenol and benzoic acid obtained in this work is smaller than that between 7CoH and ncooH.…”

Section: Resultsmentioning

confidence: 99%

Contribution of Substituent Groups to the Extractability of Phenols and Benzoic Acids

Hagiwara

Motomizu

1991

ANAL. SCI.

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The contribution of substituent groups to the extractability of phenols and benzoic acids was examined by using a substituent constant, n, derived from the distribution coefficients of nonionic substances. This constant is defined as nx=log KD(x)-log KD(H), where KD(x) is the distribution coefficient of a derivative and log KD(H) is that of the parent compound. The substituent constants of the groups at the ortho-position of phenol were found to vary with a variation of the extraction solvent, possibly due to competition between the hydration and solvation of an organic solvent. From the KD values of the phenols and benzoic acids determined between chloroform and water, the substituent constants of halogeno, cyano, trifluoromethyl and nitro groups were calculated. In phenols, the m values of the ortho-substituting group (ic°) were greater than those of the mew-and para-substituting group, irm and np, respectively, whereas in benzoic acids i° are smaller than xm and np. Such results can be explained by a masking effect and the overlapping effect: the masking effect increases the n° values, whereas the overlapping effect decreases the n° values. A method for predicting the total n values of di-and tri-substituted phenols and benzoic acids is proposed.

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Liquid-liquid distribution behavior of quaternary ammonium salts

Cited by 23 publications

References 0 publications

Adsorption of tetrahexylammonium – bromothymol blue ion-pairs at the chloroform–water interface

Adsorption of tetrahexylammonium – bromothymol blue ion-pairs at the chloroform–water interface

Solvent Extraction of Antimony(V) as Hexachloroantimonate(V) with Quaternary Ammonium Ions

Contribution of Substituent Groups to the Extractability of Phenols and Benzoic Acids

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