New spot tests for thallium(I), bismuth(III), and iodide

Microchimica Acta - New spot tests are described for the selective detection of Tl(I), Bi(III), and I? ions, with limits of detection 4 μg, 5 μg, and 15 μg respectively, and...     

Reaction between copper(I)-thiourea and bismuth(III)-thiourea complexes in presence of iodide. New spot-tests for copper(II) and bismuth(III)

New and very simple spot tests are described for the detection of Bi(III), Cu(II) and I(-) ions with limits of detection of 3, 8, and 75 mug/0.05 ml respectively. Tests are also described for such combinations as Bi(III) + I(-); Bi(III) + Cu(II); and Bi(III) + Cu(II) + I(-). All the tests are based on the formation of an orange or red-orange precipitate of bismuth(III)-copper(I)-iodide-thiourea complex, for which the formula [Bi(tu)(3)I(3).Cu(tu)(3)I] (where tu = thiourea) is proposed. This complex is produced in various ways by the interaction of Bi(III), Cu(II), and I(-) ions with thiourea. Most cations and anions do not interfere, but Tl(I), Cs(I), SO(2-)(3), S(2)O(2-)(3), EDTA, and oxidizing ions such as NO(-)(2), IO(-)(3), IO(-)(4), BrO(-)(3), and MnO(-)(4) do. The complex hexakis(thioureato)sulphatomonoaquodicopper(I) [Cu(2)(tu)(6)SO(4).H(2)O] is proposed as a new spot-test reagent for Bi(III) and I(-) ions, although the sensitivity for the latter is poor.     

Impedance measurements for pressed-pellet electrode membranes based on silver iodide and silver iodide/silver sulfide with solution contacts

Impedance characteristics of pressed pelletm membranes based on silver iodide, mixed $\text{AgI}\text{Ag}{}^2\text{S}$ with molar ratios of 10:1, 1:1 and 1:10, and silver sulfide are investigated by using solution contacts and a computer-controlled automatic measuring system. As membrane bulk impedances were commensurable with those of contacting solutions, special regression methods were necessary for evaluation. Typical resistivities were, in the order indicated above, as follows: 14, 2, 0.3, 0.1 and 0.1 kΩ cm, respectively. Thus, mixing of silver sulfide into the silver iodide matrix decreases dramatically the membrane resistance. These measured bulk membrane resistances are not affected by changes in composition and concentration of bathing solutions, and even the low-frequencies parts of impedance plots were not influenced by different stirring conditions, even in presence of corroding solutions such as thiosulfate or cyanide. Sorption also had no manifest effect on the impedance characteristics, but increasing pressure during membrane preparation or heat treatment significantly increased membrane resistances.     

"One-step" alkynylation of adamantyl iodide with silver(I) acetylides

[reaction: see text] Silver(I) acetylides allow one-step alkynylation of adamantyl iodide in yields ranging from 25 to 68%.     

Structural studies of silver(I) coordination polymers with aryl iodide derived ligands

This paper reports novel silver polymers, built with iodine--silver interactions, with interesting structural motifs. Four silver(I) coordination polymers of the aryl iodide derived ligands, triiodobenzoic acid (HL1), tris(4-iodophenyl)amine (L2), and 5,7-diiodo-8-hydroxyquinoline (HL3), have been synthesized and characterized by X-ray crystallography. Treatment of Ag(CH3COO) with HL1 yielded [Ag(L1)] (1), whose structural analysis revealed 2D layers of ladders connected through weak Ag...I interaction. Reactions of AgClO4 and L2 in benzene and nitrobenzene afforded, respectively, two different products, [Ag(L2)(H2O)]ClO4.C6H6(2) and [Ag(L2)(ClO4)](3). While the structure of 2 could be described as a 2D layer of square and octagons perpendicular to [100], complex 3 is formed by 2D layers of the same topology of 2 (8(2).4), alternating as ABAB. In contrast, complex 4, [Ag2(H2L3)(CF3SO3)3], obtained by reaction of Ag(CF3SO3) and HL3, was found to consist of a 2D layer based on columnar arrays AgH2L3-Ag(triflate). The solid-state FT-IR and 109Ag NMR spectra of theses complexes are discussed on the basis of their crystal structures.     

Environmentally friendly organic synthesis using bismuth compounds: bismuth(III) iodide catalyzed deprotection of acetals in water

The chemoselective deprotection of a wide range of acetals and ketals in water is catalyzed by bismuth(III) iodide. Bismuth(III) compounds are remarkably nontoxic and hence are attractive as environmentally friendly catalysts.     

The studies of the reaction of bismuth(III) with iodide at nanogram level by thermal lensing

By the example of the analytical system based on the reaction of bismuth with iodide, it is shown that thermal lens spectrometry can be used for studying changes in analytical reactions at the nanogram level of reactants. The stability constants of bismuth(III) iodides at the concentration level are found. The solubility constants of iodides of metals interfering with bismuth determination are estimated. It is shown that the due regard to the new conditions could enhance the sensitivity and selectivity of determination.     

Enthalpies of formation of adducts of antimony(III) iodide with pyridine and methyl-pyridines

Solid adducts of formula SbI₃·L (L = pyridine or 2-, 3- or 4-methylpyridine abbreviated as Py, 2MPy, 3MPy or 4MPy) were synthesized and characterized by elemental analysis, IR spectroscopy and thermal analysis. IR data showed that coordination to antimony is through nitrogen. Thermal degradation of adducts starts at 431, 423, 413 and 411 K for Py, 2MPy, 3MPy and 4MPy, respectively. Reaction-solution calorimetry was used to evaluate the enthalpy change of reaction: SbI₃(cr) + L(l) = SbI₃·L(cr), 61.13 ± 1.75, −82.60 ± 1.55, −67.50 ± 0.97 and −74.10 ± 1.19 kJ mol⁻¹, respectively. Enthalpy change values for decomposition of adducts, lattice enthalpies and enthalpies of the Lewis acid-base reaction in the gas phase were calculated through appropriate thermochemical cycles. Mean SbN bond enthalpies were estimated as 134 ± 3, 154 ± 3, 140 ± 3 and 147 ± 4 kJ mol⁻¹, for Py, 2MPy, 3MPy and 4MPy, respectively.     

Layered organic-based metal iodide-polyiodide with unique mixed-valent gold(I/III) iodide chains

We report the synthesis, optical spectrum, and crystal and electronic structures of a new organic-inorganic hybrid compound, [(p-NH3C6H4)2CH2]4 [(AuI2)(AuI4)(I2)2(I5)2Cl4], with unique mixed-valent gold(I/III) chains. The chains feature face-shared octahedral [AuIAu(III)I6]2- units and are embedded within polyiodide layers. The new mixed-valent gold iodide crystallizes in the orthorhombic space group Pnnm, with a = 27.0703(2), b = 8.9363(5), c = 18.4280(1) angstroms, Z = 2, and exhibits an optical band gap of 0.53 eV.     

Syntheses and characterization of a new nano-structured bismuth(III) bromide coordination polymer; new precursor for preparation of bismuth(III) bromide and bismuth(III) oxide nanostructures

Nanoparticles of a Bi(III) coordination polymer, {[Bi(μ-4,4′-bipy)Br₄] · (4,4′-Hbipy)} _n (1) (4,4′-bipy = 4,4′-bipyridine), were synthesized by a sonochemical method. The new nanoparticles were characterized by scanning electron microscopy, X-ray powder diffraction (XRD), IR spectroscopy, and elemental analyses. Compound 1 was structurally characterized by single-crystal X-ray diffraction. The thermal stabilities of 1 as bulk and at nanosize were studied by thermal gravimetric (TG) and differential thermal analyses (DTA). The Bi₂O₃ and BiBr₃ nanostructures were obtained by calcinations of nanostructure of 1 in air and argon.     

New hydrazine sensors based on electropolymerized meso-tetra(4-sulphonatephenyl)porphyrinate manganese(III)/silver nanomaterial

A new electrocatalytic active porphyrin nanocomposite material was obtained by electropolymerization of meso-tetra(4-sulphonatephenyl)porphyrinate manganese(III) complex (MnTPPS) in alkaline solutions containing sub-micromolar concentrations of silver chloride. The modified glassy carbon electrodes efficiently oxidize hydrazine at 10mV versus Ag/AgCl, dramatically decreasing the overpotential of conventional carbon electrodes. The analytical characteristics of this amperometric sensor coupled with batch injection analysis (BIA) technique were explored. Wide linear dynamic range (2.5x10(-7) to 2.5x10(-4)molL(-1)), good repeatability (R.S.D.=0.84%, n=30) and low detection (3.1x10(-8)molL(-1)) and quantification (1.0x10(-7)molL(-1)) limits, as well as very fast sampling frequency (60 determinations per hour) were achieved.     

Complexes of silver(III) with oxoanions

Silver(III) has a half-life at pH 11 of several hundred seconds in aqueous solutions in the presence of 0.1–1.0 M concentrations of certain basic oxoanions (Oxo) (phosphate, carbonate, borate, pyrophosphate, and arsenate). This compares with a lifetime of a few seconds at pH 11 in the absence of these oxoanions. UV-visible spectra and kinetic data for these solutions are interpreted as evidence for the following equilibria in the pH range 9–13.Ag(OH)₄^?1 + H₂O ? Ag(OH)₃H₂O + OH^? (1)Ag(OH)₄^?1 + Oxo ? Ag(OH)₃Oxo + OH^? (2)Ag(OH)₃Oxo + H₂O ? Ag(OH)₂(Oxo)H₂O + OH^? (3) Values of K₃ lie in the range 10^?3 < K₃ <10⁴ M for the systems studied. K₂ is estimated to be ～10² for phosphate and slightly smaller for the other systems. Ag(OH)₄^? undergoes an unusual reaction with pyrophosphate at pH ～ 8 to form a novel silver(II) complex, [Ag(P₂O₇)₂]^6?, for which EPR and electronic absorption spectral parameters are reported.     

Alkylenedithiophosphate derivatives of arsenic(III), antimony(III) and bismuth(III)

Tris(alkylenedithiophosphates) of arsenic(III), antimony(III) and bismuth(III),

have been synthesized by the reactions of alkylenedithiophosphoric acids with metal oxides and chlorides and of their ammonium salts with metal chlorides in suitable solvents. Mixed chloride alkylenedithiophosphates of arsenic(III) and antimony(III),

have been obtained by the reactions of metal chlorides with ammonium alkylenedithiophosphates at 1 : 1 and 1 : 2 molar ratios or alternatively by the co-disproportionations reactions of metal chlorides with metal tris(alkylenedithiophosphates) at different (2 : 1 and 1 : 2) molar ratios. These new compounds have been characterized by elemental analyses, molecular weight measurements and spectroscopic (IR, and ¹H and ³¹P NMR) data. Chelated structures with bidentate alkylenedithiophosphate groups have been proposed for all these derivatives.     

Liquid-liquid extraction of arsenic(III), antimony(III) and bismuth(III) with potassium ethyl xanthate

Summary Methods are described for quantitative extraction of arsenic(III), antimony(III) and bismuth(III) with potassium ethyl xanthate-carbon tetrachloride. The optimum acidity conditions are 0.1–0.2 M hydrochloric acid for arsenic, 1.8–2.5 M hydrochloric acid for antimony and p_H 1.5–4.0 for bismuth. From the organic extracts arsenic and antimony are estimated by conventional iodometric methods while bismuth is determined spectrophotometrically at 400 nm. The effect of acidity, reagent concentration, period of extraction and diverse ions are discussed. The infra-red spectra are also described.

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Zusammenfassung Verfahren für die Extraktion von As(III), Sb(III) und Bi(III) mit Kaliumäthylxanthat/Tetrachlorkohlenstoff werden beschrieben. Die optimalen Aciditätsbedingungen sind: 0,1–0,2 M HCl für As, 1,8–2,5 M HCl für Sb und p_H 1,5–4,0 für Bi. As und Sb werden nach Entfernung des organischen Lösungsmittels jodometrisch bestimmt; Bi wird im gelb gefärbten Extrakt spektrophotometrisch bei 400 nm bestimmt. Der Einflu\ der Acidität, der Reagenskonzentration, der Schütteldauer und verschiedener Fremdionen auf die Extraktion wird besprochen. Die IR-Spektren der gebildeten Komplexe werden diskutiert.

     

The effect of temperature on the formation of bismuth(III) monocysteine and monothiosemicarbazide complexes

The stability constants of monocomplexes of cysteine (H₂Cys) and thiosemicarbazide (Tsc) with bismuth(III) at 288, 313 and 333 K in 0.5 M HClO₄ and an ionic strength of 2(NaClO₄) were determined by spectrophotometry. On the basis of a substantial difference in the stability constants of bismuth monocomplexes with H₂Cys and Tsc, the high acidity of the investigated solutions, and known coordination modes of these ligands in crystalline compounds, the formation of Bi(HCys-O,S)²⁺ and Bi(Tsc-N, S)³⁺ is suggested.