Tetrabutylammonium Bromide Solution Research Articles

Electrical Conductances of Tetrabutylammonium Bromide, Sodium Tetraphenylborate, and Sodium Bromide in Acetonitrile (1) + Water (2) Mixtures at (308.15, 313.15, and 318.15)K

The electrical conductances of solutions of tetrabutylammonium bromide (Bu4NBr), sodium tetraphenylborate (NaBPh4), and sodium bromide (NaBr) in acetonitrile (1) + water (2) mixed-solvent media containing 0.20 and 0.40 volume fractions of acetonitrile have been reported at (308.15, 313.15, and 318.15) K. The conductance data have been analyzed by the 1978 Fuoss conductance−concentration equation in terms of the limiting molar conductance (Λ0), the association constant (KA), and the association diameter (R). The ionic contributions to the limiting molar conductance have been estimated using tetrabutylammonium tetraphenylborate (Bu4NBPh4) as the “reference electrolyte”. These three electrolytes are found to exist as free ions in both solvent mixtures in the temperature range of (308.15 to 318.15) K. Besides the relative permittivity and the viscosity of the media, specific interactions of the ions with the solvent media have been found to exhibit a profound influence on their mobilities. Although the association constants of the electrolytes do not vary significantly as a function of temperature, the limiting equivalent conductances of the electrolytes as well as the single-ion conductivity values increase appreciably with temperature.

Selective extraction and separation of textile anionic dyes from aqueous solution by tetrabutyl ammonium bromide

Tetrabutyl ammonium bromide (TBAB) has been demonstrated to be a very effective reagent for selective extraction of anionic dyes from aqueous solution. The solution of TBAB in methylene chloride is able to extract 98% of 50 mg L −1 concentration of dye solution. The distribution ratio is reasonably high ( D = 49.0) even in the presence of excess chloride and sulphate ions. Extracted dye in the organic phase can be back extracted with excess of salicylic acid and sodium carbonate solution. After salicylic acid–sodium carbonate stripping and water washing, the organic layer of TBAB becomes regenerated and it can be recycled for further extraction. The stripped solution on acidification precipitated salicylic acid and the dye is recovered.

Electrical Conductances of Tetrabutylammonium Bromide, Sodium Tetraphenylborate and Sodium Bromide in 2-Ethoxyethanol in the Temperature Range 35–50°C

Abstract The electrical conductances of the solutions of tetrabutylammonium bromide (Bu4NBr), sodium tetraphenylborate (NaPh4B) and sodium bromide (NaBr) in 2-ethoxyethanol have been reported at 35, 40, 45 and 50°C. The conductance data have been analyzed by the 1978 Fuoss conductance–concentration equation in terms of the limiting molar conductance (Λ0), the association constant (K Λ) and the association diameter (R). The ionic contributions to the limiting molar conductances (Λ0) have been estimated using the “reference electrolyte” tetrabutylammonium tetraphenylborate (Bu4NPh4B). Appreciable ionic association was observed for all of these electrolytes which were found to exist in the form of solvent-separated ion-pairs in 2-ethoxyethanol. The tetrabutylammonium and tetraphenylborate ions are found to remain scarcely solvated whereas the sodium and bromide ions undergo substantial solvation in 2-ethoxyethanol medium in the temperature range investigated here.

Flow injection indirect amperometric detection of ammonium ions using a clinoptilolite-modified electrode

A copper ion-doped clinoptilolite-modified carbon paste electrode was evaluated as an amperometric sensor for non-electroactive ammonium cations in flow injection analysis. The electrochemical activity of copper was prevented in electrolyte solutions containing size-excluded cations such as tetrabutylammonium, while the presence of non-size-excluded cations such as ammonium gave rise to appreciable responses. Consequently, the injection of ammonium samples at the electrode surface (into a carrier stream made of tetrabutylammonium bromide solution) resulted in peak currents proportional to the concentration of the analyte NH 4 +. After optimisation of the experimental conditions, very reproducible results (standard deviations <1%, n=10) were obtained, linear calibration was achieved in the 2×10 −5 M to 1×10 −3 M concentration range, and the detection limit was 5×10 −6 M. The effect of interfering cations was also discussed and the sensor's performance was evaluated for the analysis of ammonium in synthetic ground water.

Dielectric Properties of an Electrolyte Solution at Low Reduced Temperature

We report on the complex dielectric permittivity up to 20 GHz of solutions of tetrabutylammonium bromide in carbon tetrachloride at salt concentrations between 0.01 and 1 mol dm-3, where the molar ...

The Methylviologen-Doped Zeolite Modified Electrode as a New Detector for Suppressor Free Ion Chromatography

A methylviologen-doped zeolite modified carbon paste electrode was applied to the amperometric detection of alkali metal cations in ion chromatography. The detection principle is based on the ion exchange of methylviologen by the target cationic analyte, followed by the reduction of methylviologen at the electrode surface at an operating potential of −0.85 V (vs. SCE). When using a solution of tetrabutylammonium bromide as the mobile phase, the background response was very low because of the size exclusion of tetrabutylammonium ions from the zeolite framework, and the modified electrode was only sensitive to non size-excluded cations. In a large volume wall-jet cell configuration, the sensor allowed the analysis of non reducible non size-excluded cations after their separation on an ion exchange column, in both the presence and the absence of dissolved oxygen. Use of a mobile phase with cations too large to be detected by the zeolite modified electrode did not require any further suppressor technique.

Complexation studies on inositol-phosphates. V. Cu 2+, Zn 2+, Fe 2+ and Fe 3+ complexes of some myo-inositol triphosphates

Potentiometry and 31P NMR spectroscopy have been used to study the protonation and complexation properties of some myo-inositol triphosphates (Ins(1,2,6)P 3, Ins(1,3,5)P 3, and Ins(2,4,6)P 3) with Cu 2+, Zn 2+, Fe 2+, and Fe 3+. The study was performed for all the ligands at 25°C in a 0.1 M tetrabutylammonium bromide solution (medium 1) and in addition, for Ins(1,2,6)P 3, at 37°C in a 0.2 M KCl medium (medium 2). The position of the phosphate groups around the inositol ring largely influences the basicity of the ligand. Log β 011 has the highest value for Ins(1,2,6)P 3 which displays three vicinal phosphates. When no interfering cations such as K + are present, M 2HL, M 2L, MHL, ML, and MOHL complexes were found for most of the systems. Although the stability of the complexes follows the Irving-Williams rule, i.e., Cu(II) > Zn(II) > Fe(II), no real selectivity of complexation is observed. A 31P NMR titration was performed for the Zn 2+- H+-Ins(1,2,6)P 3 system. The resulting titration curves, compared with those obtained in the absence of metal showed two opposite effects: i) a downfield shift due to the competition of the metal with the proton, ii) an upfield shift corresponding to the binding of Zn 2+. From these curves it can, in addition, be concluded that the cation in the mononuclear species is mainly coordinated to P1 and P2 whereas the second cation of the homodinuclear complex is stabilized by P6.

Determination of midazolam and two of its metabolites in human plasma by high-performance liquid chromatography

A high-performance liquid chromatographic assay coupled with UV detection (254 nm) has been developed for the determination of midazolam and two of its hydroxylated metabolites, 1-hydroxymidazolam (1-OH) and 4-hydroxymidazolam (4-OH), in human plasma. Following a novel solid-phase extraction procedure, midazolam and its metabolites are well recovered from plasma. The analytes were extracted with C 1 cartridges and the extracts were evaporated to dryness. The dry residues were dissolved in 200 μl of mobile phase [0.02 M ammonium phosphate monobasic buffer—methanol—acetonitrile (60:35:5, v/v) (300 ml), 600 μl of 0.2 M tetrabutylammonium bromide solution, adjusted to a pH * (apparent pH) of 4.10]. The separation of the analytes was performed on a Spherisorb C 8 column (10 cm × 4.6 mm I.D.) maintained at 30°C. The mobile phase was pumped at a flow-rate of 1.5 ml/min. The method has a lower limit of quantitation of 15 ng/ml of plasma for midazolam and proved to be reproducible (inter-assay precision 5.4%) and accurate (94 ± 5%) over the therapeutic range of concentrations.

Raman spectral studies of ion–molecular interactions of lithium bromide and lithium iodide with dimethyl sulphoxide

AbstractRaman spectra in the CH and SO stretching and SO bending regions are reported for solutions of lithium halides and tetrabutylammonium bromide (TBAB) in dimethyl sulphoxide (DMSO) and DMSO‐d6. The CD stretching band of DMSO‐d6 shows two components in solutions of TBAB with DMSO‐d6, whereas the CH stretching band of DMSO for solutions of LiX (X = Br and I) in DMSO show some broadening and asymmetry in the low‐frequency region. The SO stretching bands show changes in band shapes and band contours in solutions of electrolytes in DMSO. Fourier deconvolution of CH and SO stretching bands were carried out to gain more information regarding number of components present under the broad structured bands. All the solutions show a significant decrease in the intensity of the SO bending bands when compared with the neighbouring CS bending band. The results are discussed in terms of anion‐ and cation–molecular interactions with DMSO.

Raman spectral studies on interactions of Br − ions with CD 3 group of acetonitrile, nitromethane and dimethyl sulfoxide

Raman spectra in the CD 3 stretching region are reported for solutions of tetrabutyl ammonium bromide (TBAB) in deuterated acetonitrile (AN- d 3), nitromethane (NM- d 3) and dimethylsulfoxide (DMSO- d 6). New bands are found to appear in the low frequency regions of CD stretching vibrations in solutions of TBAB in AN- d 3 and DMSO- d 6 due to the anion—molecular complexes formed whereas only an increase in half band width of the CD stretching band is observed in solutions of TBAB in NM- d 3. Raman spectra of three component and four component systems involving TBAB, AN- d 3, NM- d 3 and water are also reported with a view to obtaining information on preferential solvation of the anions by water.

Flow viscometer for solutions that make a glass wall water repellent

A constant-level viscometer has been designed especially for solutions that make glass water repellent. The lower meniscus remains at a constant level (±0.02 mm) during the flow period. Lower and upper meniscus corrections and the drainage error are discussed. It is shown that the performance of the viscometer is at least as good as that of the suspended-level type for solutions that completely wet the glass wall, as KCl in water. For tetraethyl and tetrabutylammonium bromide solutions in water, this performance is free of the inaccuracies described in the literature. For Bu4NBr the relative viscosities measured at twelve concentrations in the range 10−4 to 160×10−4 M at 25°C, show a standard deviation of 0.01% about the best fit to the extended Jones–Dole equation. From these data the corresponding A coefficient has been determined, and found to agree with the value from theory.

Dielectric relaxation of lithium perchlorate and tetrabutylammonium bromide solutions. A model of ion pairs

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDielectric relaxation of lithium perchlorate and tetrabutylammonium bromide solutions. A model of ion pairsHubert. Cachet, Alain. Cyrot, Mohamed. Fekir, and Jean Claude. LestradeCite this: J. Phys. Chem. 1979, 83, 18, 2419–2429Publication Date (Print):September 1, 1979Publication History Published online1 May 2002Published inissue 1 September 1979https://doi.org/10.1021/j100481a023RIGHTS & PERMISSIONSArticle Views118Altmetric-Citations19LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (1 MB) Get e-Alerts

Chronopotentiometric investigation of the diffusion overvoltage at the interface between two non-miscible solutions: I. Aqueous solution-tetrabutylammonium ion specific liquid membrane

The system studied consists of an aqueous solution of tetrabutylammonium bromide and NaBr in contact with a nitrobenzene solution of tetrabutylammonium tetraphenylborate. When a constant current crosses the interface of these two nonmiscible solutions, the aqueous solution being on the positive side, the overvoltagetime curves obtained are identical to the classical chronopotentiograms which are obtained with metal-solution systems. One can show that, before the transition time, the current is carried through the interface only by the tetrabutylammonium ions. In the case where only the diffusion overvoltage occurs, an expression of the overvoltage has been established.

Solubility of helium and methane in aqueous tetrabutylammonium bromide solutions at 25 and 35.deg.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSolubility of helium and methane in aqueous tetrabutylammonium bromide solutions at 25 and 35.deg.Andre Feillolay and Michel LucasCite this: J. Phys. Chem. 1972, 76, 21, 3068–3072Publication Date (Print):October 1, 1972Publication History Published online1 May 2002Published inissue 1 October 1972https://doi.org/10.1021/j100665a028RIGHTS & PERMISSIONSArticle Views81Altmetric-Citations17LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (595 KB) Get e-Alerts

Ultrasonic Relaxation in Aqueous Solutions of Tetraalkyl Ammonium Salts

Ultrasonic-absorption measurements have been made with send-receive pulse techniques in aqueous solutions of tetrabutyl ammonium bromide as a function of frequency (up to 500 MHz), concentration, pressure (up to 2 kbar), and temperature. A double-Carstensen cell system in a high-pressure vessel has been used for the determination of the pressure dependence at and below 50 MHz. The results give evidence of two relaxation frequencies, one above 300 MHz for concentrations of 0.6 M or greater at 25°C and 1 atm, and the second below 50 MHz. The molecular absorption cross section increases abnormally fast with increasing concentration above 1 M, particularly at lower frequencies, suggesting that a large number of solvent molecules are involved with the solute in the low-frequency relaxation process. Various mechanisms are considered and predictions based thereon compared with experiment. The high-frequency relaxation is attributed to a second-order diffusion controlled-association process. [Research partially supported by the Office of Saline Water and the Office of Naval Research.]