Tetraphenylborate Ion Research Articles

A potentiostatic study of hydrophobic ion transfer across lipid bilayer membranes: Part II. Transport of tetraphenylborate ions at high concentration in the aqueous solution

The transfer of tetraphenylborate (TPB −) ions across black lipid membranes in aqueous solutions ranging from 10 −5 M to 10 −3 M, has been studied under potentiostatic conditions. A theoretical treatment of the problem accounts for the two time constants given and for the diffusion current for prolonged periods of time if one assumes that the adsorption-desorption transfer currents are large. This is tantamount to considering that these two processes are highly reversible and that the dipolar nature of the drop in potential between the closest approach and adsorption planes determines the adsorption. The resistances corresponding to the translocation and adsorption-desorption processes have thus also been evaluated. Using these results and those given by surface potential measurements on monolayers of glycerylmono-oleate, the number of adsorbed ions has been calculated. This has led to an explanation of the well known conductance maximum encountered when the concentration of the tetraphenylborate ions varies.

Inner Voltage Clamping: A Method for Studying Interactions among Hydrophobic Ions in a Lipid Bilayer

Ketterer, et al. (1971) have suggested that a combination of electrostatic and chemical interactions may cause hydrophobic ions absorbed within a bilayer lipid membrane to reside in two potential wells, each close to a membrane surface. The resulting two planes of charges would define three regions of membrane dielectric: two identical outer regions each between a plane of absorbed charges and the plane of closest approach of ions in the aqueous phase; and the inner region between the two planes of adsorbed charges. The theory describing charge translocation across the inner region is based on a simple three-capacitor model. A significant theoretical conclusion is that the difference between the voltage across the inner region, V(i), and the voltage across the entire membrane, V(m), is directly proportional to the amount of charge that has flowed in a voltage clamp experiment. We demonstrate that we can construct an "inner voltage clamp" that can maintain, with positive feedback, a constant inner voltage, V(i). The manifestation of proper feedback is that the clamp current (after a voltage step) will exhibit pure (i.e., single time-constant) exponential decay, because the voltage dependent rate constants governing translocation will be independent of time. The "pureness" of the exponential is maximized when the standard deviation of the least-square fit of the appropriate exponential equation to the experimental data is minimized. The concomitant feedback is directly related to the capacitances of the inner and outer membrane regions, C(i) and C(o).Experimental results with tetraphenylborate ion adsorbed in bacterial phosphatidylethanolamine/n-decane bilayers indicate C(i) approximately 5 . 10(-7)F/cm(2) and C(o) approximately 5 . 10(-5)F/cm(2).

Spectrophotometric determination of thiosulfate and tetraphenylborate ions through ligand exchange reaction at solid surface

A Spectrophotometric method is presented for the microanalysis of analytically important thiosulfate and tetraphenylborate anions in an aqueous solution. The method is based on ligand exchange in a dynamic approach incorporating a solid reagent mercuric chloranilate. The common cations Na+, K+, Al3+, Ca2+, and Mg2+ do not interfere and the anions CH3COO−, C2O42−, SO4−, C3H4OH-(COO)33− and NO3− do not cause any adverse effects. The heavy metals Pb2+, Cd2+, Fe2+, Cu2+, and Zn2+ cause a negative interference while the halogens and SCN− type of anions give a positive interference. The method is sensitive up to 5 ppm of tetraphenyl-borate anion and 10 ppm of the thiosulfate anion.

Solvent mediator studies on barium ion-selective electrodes based on a sensor of the tetraphenylborate salt of the barium complex of a nonylphenoxypoly-(ethyleneoxy)ethanol

The barium ion-selective electrode sensor based on the neutral carrier complex of a nonylphenoxypoly(ethyleneoxy)ethanol containing 12 ethylene oxide units and 2 mol of tetraphenylborate ion per mole of Ba2+(12 EOU. Ba.2TPB) requires a more viscous solvent mediator than 4-nitroethylbenzene for long-life poly(vinyl chloride)(PVC) matrix-membrane barium ion-selective electrodes. Both 2-nitrophenyl octyl ether and di-2-nitrophenyl ether used in conjunction with the sensor in a PVC matrix membrane give functional barium ion-selective electrodes, but those with di-2-nitrophenyl ether mediator are far superior with lifetimes of about 30 d. Barium ion-selective electrodes with the sensor and mediator in liquid membranes can be made for a wide range of nitro-aromatic solvent mediators.Barium ion-selective electrodes made from discs taken from a master membrane containing 0.40 g of a saturated solution of Antarox CO-880. Ba.-2TPB in di-2-nitrophenyl ether can be used as indicator electrodes for the potentiometric titration of SO42– with Ba2+. A role for a potentiometric titration finish in the determination of sulphur in organic compounds by the oxygen-flask method is recommended.

Potential energy barriers to ion transport within lipid bilayers. Studies with tetraphenylborate

Tetraphenylborate-induced current transients were studied in lipid bilayers formed from bacterial phosphatidylethanolamine in decane. This ion movement was essentially confined to the membrane in terior during the current transients. Charge movement through the interior of the membrane during the current transients was studied as a function of the applied potential. The transferred charge approached an upper limit with increasing potential, which is interpreted to be the amount of charge due to tetraphenylborate ions absorbed into the boundary regions of the bilayer. A further analysis of the charge transfer as a function of potential indicates that the movement of tetraphenylborate ions is only influenced by a certain farction of the applied potential. For bacterial phosphatidylethanolamine bilayers the effective potential is 77 +/- 4% of the applied potential. The initial conductance and the time constant of the current transients were studied as a function of the applied potential using a Nernst-Planck electrodiffusion regime. It was found that an image-force potential energy barrier gave a good prediction of the observed behavior, provided that the effective potential was used in the calculations. We could not get a satisfactory prediction of the observed behavior with an Eyring rate theory model or a trapezoidal potential energy barrier.

Conformation of the tetraphenylborate ion

Conformation of the tetraphenylborate ion

The Extraction of Tris(1,10-phenanthroline)ruthenium(II). I. Distribution Studies

Abstract Tris(1,10-phenanthroline)Ru(II) was extracted into various organic solvents with several anions, such as the perchlorate ion, the iodide ion, or the thiocyanate ion. The association constants of ion-pairs were successfully determined by analysis of the extraction curves in the solvents with low polarities. It was found that the ion-pairs were extracted mainly as the associated form and that only the first-step dissociation could slightly occur (<10−7) in such solvents; furthermore, the degree of association was considerable even in water. Therefore, the distribution ratio of the complex cation must be governed by both the hydration energy of the counter anion and the solubility parameter of the extraction solvent rather than its dielectric property. An abnormal decrease in the distribution ratio was observed when the tetraphenylborate ion was used as the counter anion. This phenomenon can be explained clearly in terms of the hydrotropism which was often encountered in the solution of an electrolyte with a large ion.

The Tetraphenylborate Ion as NMR‐Shift Reagent for Sulfonium Compounds

The Tetraphenylborate Ion as NMR‐Shift Reagent for Sulfonium Compounds

Amperometric Method for the Rapid Determination of Tetraphenylborate lon and Its Appiication to the Analysis of Potassium lon

Tetraphenylborate ion was titrated in the presence of a neutral supporting electrolyte (such as sodium nitrate) with a silver nitrate solution by short-circuit amperometry using a rotating platinum wire electrode (1000 rpm) as the indicator and a reference SCE electrode. A O.004mol/1 sodium tetraphenylborate s 1ution in the prese ce f o.1 m 111 sodium nitrate was titrated accurately with a coefficient of variation less than O.1%. Surface active agent such as poly (vinyl pyrrolidone), triton X-100 and triton X-405 at the concentration less than O.0160. did not interfere with the titration.A method for the determination of potassium ion was as follows. An excess of sodium tetraphenylborate solution was added to an aqueous solution of potassium nitrate at about 800C to form the precipitate of potassium tetraphenylborate. After the solution was cooled to room temperature, sodium nitrate (final concentration O.1 mol/1) was added as the supporting electrolyte, and poly(vinyl pyrrolidone) (O. Ol%)to prevent the potassium tetraphenylborate precipitate from reacting with silver ion. Then the residual tetraphenylborate ion was titrated.This method is applicable to the determination of potassium in sea water. Firstly, the sum of the residual quantity of tetraphenylborate ion added and all of the halide ions were titrated, then all the halide ions were titrated with a silver nitrate solution for another a1iquot of the sample solution in order to estimate the quantity of potassium ions.

Vinyl polymerization initiated by the binary system of tetraphenylborate salts and organic acids

AbstractIt was found that the binary system of tetraphenylborate (TPB) salts and organic acids could serve as radical initiator of vinyl polymerization. From the effects of structures in TPB salts and acids on the polymerization activity, it was concluded that the reaction between the TPB ion and the proton of the acid was important in the initiating radical production. Using dimethylbenzylanilinium TPB and trichloroacetic acid (TCA), the rate of polymerization of methyl methacrylate (MMA) was found to be proportional to the square roots of the concentrations of both TPB salt and TCA, indicating that the system induced radical polymerization. The copolymerization by this system with styrene resulted in a composition curve which was in agreement with that obtained with ordinary radical copolymerization.From the product analysis and spin trapping technique for the reaction of sodium TPB with TCA, it was concluded that triphenylboron is produced first and decomposes into the phenyl radical which initiates the polymerization. On the basis of the results obtained, the initiation mechanism is presented and discussed.

Crystal and molecular structure of the complex isothiocyanato-{NN-bis-[2-(diethylamino)ethyl]-2-(diphenylarsino)ethylamine-NNN}-nickel(II) tetraphenylborate and study of the conformational energy of the tetraphenylborate ion

The structure of the title compound has been determined by Patterson and Fourier methods from photographic X-ray data, and refined by least-squares techniques to R 0·080 for 4097 observations. Crystals are triclinic, space group P, and Z= 2 in a unit cell of dimensions: a= 12·529(1), b= 13·589(1), c= 14·120(1)A, α= 95·12(1), β= 103·68(1), γ= 99·38(1)°. The co-ordination about nickel is square planar and Ni–N bond lengths are compared with those in a related five-co-ordinate complex. Non-bonding to the metal by the arsenic atom is discussed in terms of simple MO models. Calculation of the conformational energy of the isolated tetraphenylborate ion, as a function of independent rotations of the four phenyl groups, indicates that the bulky counterion does not possess a considerable degree of flexibility.

Solute-solvent interactions. VI. Specific interactions of tetraphenylarsonium, tetraphenylphosphonium, and tetraphenylborate ions with water and other solvents

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSolute-solvent interactions. VI. Specific interactions of tetraphenylarsonium, tetraphenylphosphonium, and tetraphenylborate ions with water and other solventsJ. F. Coetzee and W. R. SharpeCite this: J. Phys. Chem. 1971, 75, 20, 3141–3146Publication Date (Print):September 1, 1971Publication History Published online1 May 2002Published inissue 1 September 1971https://doi.org/10.1021/j100689a018RIGHTS & PERMISSIONSArticle Views231Altmetric-Citations73LEARN 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 (773 KB) Get e-Alerts

Indirect voltammetric determination of potassium and caesium and direct amperometric determination of potassium with tetraphenylborate using silicone rubber based graphite electrodes

The electrochemical oxidation of tetraphenylborate ions was investigated by using silicone rubber based graphite electrode. An indirect voltammetric method was elaborated for the determination of potassium and caesium. A method is also given for the determination of potassium with sodium tetraphenylborate by using amperometric end-point indication. The latter method is more accurate. The relative standard deviation is ± 0.85%.

Potentiometric determination of tetraphenylborate ions with silver nitrate. Determination of silver, potassium and thallium(I)

The potentiometric determination of tetraphenylborate with silver nitrate solution was investigated a) at i=0 in the presence of calomel reference electrode and silver resp. silicone rubber based halide-selective indicator electrodes and b) at i≠0 in the presence of silver (cathode)-calomel, silver-silver, silver-platinum, platinum-silver and graphite-silver electrode couples. An indirect method is described for the determination of potassium ions with potentiometric end-point indication. Experiments were also carried out in order to develop methods for the titration of silver, potassium and thallium(I) ions with sodium tetraphenylborate solution in the presence of anodic polarized graphite and calomel reference electrodes. The relative standard deviations were 0.38–0.49% for tetraphenylborate, 1.96% for potassium and 1.07% for thallium(I).

.pi.-Bonded complexes of the tetraphenylborate ion with rhodium(I) and iridium(I)

.pi.-Bonded complexes of the tetraphenylborate ion with rhodium(I) and iridium(I)

Response Characteristics of the Orion Potassium Ion Selective Electrode

Abstract The Orion potassium ion selective electrode (92–19) has been evaluated in terms of Nernstian response, selectivity, anion, and pH effects. The response is slightly less than Nernstian and a linear calibration curve is obtained over the concentration range 10−4 to 10−1 M potassium, The calculated selectivity ratio for potassium over sodium depends on the relative concentrations of sodium and potassium. Slight anion effects are noted with the most significant occurring with iodide, hydroxide, chromate, and oxalate. Tetraphenyl borate ion causes a large negative potential shift and this effect appears to render the electrode only moderately useful for titrations with this reagent.

The solvent extraction of alkali metal tetraphenylborates

The extraction of sodium and small amounts of potassium, rubidium and cesium from aqueous solutions containing sodium tetraphenylborate (TPB), sodium perchlorate and perchloric acid has been studied for nitromethane, nitroethane, nitrobenzene, methyl isobutyl ketone and tributyl phosphate. Nitromethane gives the highest distribution ratio (org/aq) for the perchlorates, and nitrobenzene gives the highest distribution ratio and separation factor for the tetraphenylborates. Most distribution data could be explained by assuming that the tetraphenylborates were fully dissociated in both phases. The equilibrium constants and distribution ratios increase in the order sodium<potassium<rubidium<cesium. The distribution ratio of small amounts of the heavy alkali metal ions will thus not be appreciably influenced by the concentration of sodium tetraphenylborate, but will decrease on the addition of sodium chloride or perchlorate. The effect of perchloric acid can be explained by irreversible acid hydrolysis of the tetraphenylborate ion.

The coulometric titration of tetraphenylborate ion with electrogenerated silver ion and a biamperometric end-point : Application to the determination of potassium and polyethyleneglycols

Microequivalent amounts of TPB in a 40% acetone generating electrolyte were titrated with coulometrically generated silver ions. With a biamperometric endpoint, samples of 0.1–4 μeq of NaTPB were determined with a precision with 1%. The technique was applied to the determination of potassium in potassium chloride alone and in mixtures with other salts.The overall accuracy ranged from -3 to -7% for samples of 4 μeq to 1 μeq of potassium, respectively. Artificial serum samples gave somewhat discordant results, because of difficulty in removing all interfering protein. A method was developed, for the determination of 0.1–1.0 mg of PEG 600 to 4000 with excess TPB in the presence of barium ions. With reasonable care errors may be held to within 5%.

Sodium and potassium tetraphenylborate solutions in water and 65% dioxan—water mixture—II. Spectrophotometric studies

No evidence could be found from spectrophotometric measurements for the presence of ion-pairs in solutions of sodium or potassium tetraphenylborate, either in water or in a dioxan—water mixture of dielectric constant of 20 where such species may exist, according to the analysis of conductance data reported in the preceding paper. It is suggested that the tetraphenylborate ion spectra may arise from intramolecular transitions that are insensitive to environment. To make accurate spectrophotometric measurements on the low wavelength band of the tetraphenylborate ion (197 nm) corrections are necessary for the effect of stray light. A procedure using potassium hydroxide as cut-off filter was tested on potassium iodide which gas absorption bands in the same wavelength region as tetraphenylborate ion. Extinction coefficients of potassium iodide are reported at the band maxima.

Coulometric titration of tetraphenylborate ion with electrogenerated silver ion. Application to determination of potassium, rubidium, and cesium

Coulometric titration of tetraphenylborate ion with electrogenerated silver ion. Application to determination of potassium, rubidium, and cesium