Silver Bromate Research Articles

Crystal structures and vibrational and solution and solid-state (CPMAS) NMR spectroscopic studies in triphenyl phosphine, arsine, and stibine silver(I) bromate systems, (R3E)xAgBrO3 (E = P, As, Sb; x = 1-4).

Adducts of triphenyl phosphine, triphenyl arsine, and triphenyl stibine with silver(I) bromate have been synthesized and characterized both in solution ((1)H and ESI MS spectroscopy) and in the solid state (IR, single-crystal X-ray structure analysis). The triphenyl phosphine complexes have been also investigated by (31)P[(1)H] solution and (31)P cross-polarization magic-angle-spinning (CPMAS) NMR spectroscopy. The topology of the structures in the solid state was found to depend on the nature of EPh(3) and on the stoichiometric ratio AgBrO(3)/EPh(3). In AgBrO(3)/PPh(3) (1:1)(4) (1) and AgBrO(3)/PPh(3) (1:2) (2), the bromate is in the unfamiliar and hitherto structurally uncharacterized role of coordinating ligand, the complex having a mononuclear form in 2 and a less familiar tetrameric form in 1. In AgBrO(3)/AsPh(3) (1:4).CH(3)OH (7) and AgBrO(3)/SbPh(3) (1:4).C(2)H(5)OH (11), the cations are the familiar homoleptic [Ag(EPh(3))(4)](+) array with the bromate role simply that of counterion. The AgBrO(3)/AsPh(3) (1:2)(2).0.7"H(2)O" derivative (6) is binuclear L(2)Ag(mu-BrO(3))(2)AgL(2) with a four-membered ring core (L = AsPh(3)).

Thermodynamics of Transfer and Solvent Transport of Silver(I) Sulphate, Bromate and Iodate in Ethanol-Pyridine Mixtures

The Gibbs energies of transfer and the solvent transport numbers of silver(I) salts viz. silver sulphate, silver bromate and silver iodate have been determined in ethanolpyridine mixtures over the complete range of compositions at 30°C. The solubility of all the salts passes through a maximum near Xpy =0.6, Xpy =0.5 and Xpy =0.6 for silver sulphate, bromate and iodate respectively and decreases subsequently with further addition of pyridine. The standard Gibbs energies of transfer from ethanol to ethanolpyridine mixtures were calculated from the thermodynamic solubility products of the salts in these mixtures and found to decrease up to Xpy =0.3, Xpy =0.3 and Xpy =0.6 for silver sulphate, bromate and iodate respectively and then increase with the addition of pyridine. The ionic free energy of transfer of silver ion, determined on the basis of negligible liquid junction potential method, was found to be negative and decreases continuously while that of anions is positive and increases with the addition of pyridine. A large positive value of the solvent transport number, Δ is observed for all the salts in these mixtures. These results indicate that all the silver salts are heteroselectively solvated ie the silver ion is preferentially solvated by pyridine and anions by ethanol in this mixed solvent system.

ChemInform Abstract: Efficient Oxidation of Organic Compounds with Sodium and Silver Bromates NaBrO3, AgBrO3, in Non‐Aqueous Solvents in the Presence of Lewis Acids.

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Efficient Oxidation of Organic Compounds with Sodium and Silver Bromates NaBrO3, AgBrO3, in Non-Aqueous Solvents in the Presence of Lewis Acids

Abstract The synthetic utility of sodium and silver bromates in the presence of Lewis acids as catalysts in organic solvents is described. They are efficient for the oxidation of alcohols, acyloins, and hydroquinones to their corresponding carbonyl compounds. The oxidation coupling of thiols performs well in the absence of the catalysts. Silver bromate is able to transform primary benzylic and saturated alcohols, aldehydes, and primary benzylic carbon–hydrogen bonds to their carboxylic acids efficiently. Secondary benzylic carbon–hydrogen bonds are oxidized to their carbonyl compounds with sodium and silver bromates.

Gibbs Energies of Solvation and Solvent Transport of Some Silver(I) Salts in Water + N-Methyl-2-pyrrolidinone at 30 .degree.C

The preferential solvation of the silver salts silver(I) bromate, iodate, sulfate, and oxalate in the binary solvent mixtures of water and N-methyl-2-pyrrolidinone has been studied by solubility and solvent transport number measurements. The Gibbs transfer energies of the salts from water to water + N-methyl-2-pyrrolidinone mixtures, calculated from solubility data, were split into their ionic values by using the transfer energies of silver ion determined on the basis of the negligible liquid junction potential method. These data have also been compared with those obtained on the basis of the tetraphenylarsonium tetraphenylborate method. Solvent transport numbers (Δ') of N-methyl-2-pyrrolidinone were determined for all the salts by employing a concentration cell with transference as suggested by Wagner. The results have been interpreted in terms of heteroselective solvation of all the salts, with silver ion being selectively solvated by N-methyl-2-pyrrolidinone and anions by water.

Silver bromate precipitation in bromate oscillators treated with excess silver ion. A comment

Silver bromate precipitation in bromate oscillators treated with excess silver ion. A comment

Novel Flow Injection/Potentiometric Measurement of Slightly Soluble Salts in Small Volumes: Determination of Solubility Product Constants of Some Silver Salts

Abstract The flow injection technique is shown to provide fast, reliable and sensitive determination of solubility product constants of silver acetate, silver sulfate, silver oxide, silver bromate and silver chloride in microliter volume samples. Potentiometric detection using electrodes of the first kind and second kind was used for measuring silver ions and chloride ions, respectively. The solubilities were determined from measurement of the silver ion concentration in the saturated solutions. In the case of silver chloride, the solubility product constant was calculated from the concentrations corresponding to the intersection of the silver ion calibration curve and the chloride ion calibration curve, i.e., where the potentials of the two electrodes are equal. Tenth-molar sodium nitrate was used for all solutions to maintain constant ionic strength. At a concentration range of 1.00 × 10−2 − 1.00 × 10−5 M silver, and 1.00 × 10−2 − 1.00 × 10−4 M chloride, a Nernstian response of 60 m V per decade was obt...

Selective solvation of silver(I) bromate in methanol—acetonitrile and ethanol—acetonitrile mixtures at 30°C

The selective solvation of silver(I) bromate in the binary solvent mixtures of methanol + acetonitrile and ethanol + acetonitrile has been studied at 30°C by solubility and emf measurements. The solubility of the salt increases with the addition of acetonitrile up to a mole fraction ( X AN) of 0.6 and 0.7 in the case of methanol + acetonitrile and ethanol + acetonitrile respectively and then decreases with further addition of the same. The transfer free energy of the silver ion (molal scale) decreases continuously with the addition of acetonitrile in both the mixtures. The transfer free energies of bromate ion (molal scale) are found to be quite small up to X AN ≈ 0.7 in both methanol + acetonitrile and ethanol + acetonitrile mixtures and then increase. The solvent transport number Δ, of acetonitrile is positive with a maximum at X AN = 0.55 (Δ = 2.7) and at X AN = 0.45 (Δ = 2.2) for methanol + acetonitrile and ethanol + acetonitrile systems respectively. These results have been interpreted as arising due to a heteroselective solvation of the salt with the silver ion being preferentially solvated by acetonitrile and the bromate ion by the amphiprotic component which is marked especially at higher compositions.

Preferential Solvation of Silver (I) Bromate in Methanol-Dimethylsulfoxide Mixtures

The solubiltiy of silver bromate, the Gibbs transfer energy of Ag+ and BrO3 - and the solvent transport number in methanol-dimethyl sulfoxide mixtures are reported. The solubility of silver bromate increases with addition of DMSO. The Gibbs energy of transfer of the silver ion (based on the ferrocene reference method) decreases, while that of the bromate ion becomes slightly negative with the addition of DMSO. The solvent transport number A passes through a maximum (⊿ = 1.0 at XDMSO = 0.65. From these results, it is concluded that the silver ion is preferentially solvated by DMSO whereas the bromate ion shows no preferential solvation.

Ion-solvent interactions of some silver salts in N,N-dimethyl formamide-water mixtures at 30°C

The solvation behaviour of the salts, silver bromate, silver acetate and silver sulphate has been investigated in the binary mixtures of N,N-dimethyl formamide (dmf) and water. The Gibbs energies of transfer of these salts from water to water-dmf mixtures have been calculated from the solubilities of the salts in these mixtures. The transfer free energies of the salts were split into their ionic contributions by using the transfer-free energy of the silver ion in these mixtures obtained on the basis of negligible liquid junction potential (nLjp) method from independentemf measurements. The solvent transference number, Δ ofdmf, was determined byemf measurements using a suitable galvanic cell with transference. The results have been interpreted in terms of a heteroselective solvation of the salts with the silver ion selectively solvated bydmf and the anions by water.

Thermodynamics of the silver—silver iodate and silver—silver bromate electrodes in dioxane—water mixtures

Thermodynamics of the silver—silver iodate and silver—silver bromate electrodes in dioxane—water mixtures

Phase transition in silver bromate

Phase transition in silver bromate

Preferential Solvation of Ag(I) Bromate and Iodate in Dimethyl Sulfoxide–Water Mixtures

Abstract The selective solvation of Ag(I) bromate and iodate was studied in dimethyl sulfoxide–water mixtures at 30 °C by solubility and EMF measurements. The solubility of silver bromate decreases down to XDmso=0.2 and thereafter increases with addition of dimethyl sulfoxide, the solubility of silver iodate continuously decreasing under the same conditions. The transfer free energy of silver cation decreases while that of halate ions increases with the addition of dimethyl sulfoxide. The solvent transport number, Δ, passes through a maximum around XDmso=0.5 in both cases. These results were interpreted in terms of a heteroselective solvation of both the salts, the silver ion being preferentially solvated by dimethyl sulfoxide and the halate ions selectively hydrated by water in the mixtures.

Physico-chemical studies in water + dioxane mixtures: Solubility product and related thermodynamic quantities of silver bromate

Physico-chemical studies in water + dioxane mixtures: Solubility product and related thermodynamic quantities of silver bromate

Thermodynamic behaviour of silver—silver iodate and silver—silver bromate electrodes in formamide at 25°C

Thermodynamic behaviour of silver—silver iodate and silver—silver bromate electrodes in formamide at 25°C

Solubility studies in formamide: III. Solubility product of silver bromate and standard electrode potential of silver—silver bromate electrode in formamide

The solubility and solubility product of silver bromate in formamide in sodium perchlorate solutions have been determined at 25, 30 and 35°C. At these temperatures, the solubilities in pure formamide are found to be 1.837 × 10 −2, 1.967 × 10 −2, and 2.092 × 10 −2 moll −1, respectively, and the corresponding solubility products are 3.375 × 10 −4, 3.869 × 10 −4, and 4.377 × 10 −4 mol 2 l −2. The standard potentials of the Ag(s)/AgBrO 3(s)/BrO − 3 electrode have been calculated and found to be 0.4997, 0.4948, and 0.4892 V, at 25, 30, and 35°C, respectively. The mean activity coefficients of silver bromate at various rounded molarities of sodium perchlorate solutions, and the standard thermodynamic quantities for the process AgBrO 3(s) → Ag +(solvated) + BrO − 3(solvated) have been calculated at these three temperatures and compared with those for the process AgIO 3(s) → Ag +(solvated) + IO − 3(solvated) in formamide.

The Solubility of Silver Bromate and Silver Iodate in 2- Methoxyethanol-Water Mixture

The Solubility of Silver Bromate and Silver Iodate in 2- Methoxyethanol-Water Mixture

The Solubility of Silver Bromate and Silver Iodate in Ethylene Carbonate-Water Mixed Solvents and the Interaction between Ethylene Carbonate and Water Molecules

炭酸エチレン－水混合溶媒に対する臭素酸銀およびヨウ素酸銀の溶解度を25℃および35℃で測定した。その結果からハ冒ゲン酸銀の溶解平衡においてみられる炭酸エチレンと水分子聞の相互作用について考察した。臭素酸銀の溶解度はジクロルフルオレセインを指示薬とする容量分析法により求めた。またヨウ素酸銀の溶解度はチオ硫酸ナトリウム溶液を用いる通常のヨウ素滴定により求めた。ハロゲン酸銀は水にのみ溶け,炭酸エチレンに不溶であると考えることができる。 よってハロゲン酸銀の溶解度は混合溶変申の水分子の濃度に比例する。実鹸値はこの取り扱いによって期待される値よりも小さい。炭酸エチレゾと水分子の間に水素結合の生成がみられ,混合溶媒中の有効な自由水の濃度が滅少すると考えれば,この事実を説明できると思う。また,ハロゲン酸銀の溶解度は混合溶媒の誘電率の増加につれて減少し,Bornあるいはその補正理論が成立しない。

Solubility of Silver Bromate in Aqueous Solution of Urea

尿素水溶液における臭素酸銀の溶解度を15°20°25°および30℃において測定した。溶液の尿素濃度は 0～39.143% の 5種で,それらの誘電率は 76.75～99.34 の範囲であった。ついで,難溶塩の溶解度と溶媒の誘電率との関係を示す既報の理論式を中心に,測定結果を考察した。その結果,溶解度の対数と溶媒の誘電率の間に,尿素の全濃度範囲にわたり,ほぼ比例関係の成立するのを知った。また理論式を用いて算出した溶媒和半径は 5.5～7.6Å あった。

The Solubility of Silver Bromate in Isopropyl Alcohol-Water Mixture

イソプロピルアルコール-水混合溶媒における臭素酸銀の溶解度を20°C,25°Cおよび30°Cにおいて測定した。溶媒のアルコール濃度は0～69・941%の11種で,それらの誘電率は80.37～27.86の範囲であった。ついでa難溶塊の溶解度と溶媒の誘電率との関係を示す既報の理論式を中心に,測定結果を考察した。その結果,溶媒の誘電率が80～65の範囲においては,溶解度の対数は誘電率の逆数に近似的に比例するが,それ以下ではいちじるしい偏差を示すことを知った。また理論式を用いて算出した溶媒和半径は07～3.Åの範囲であった。