II ) And Thallium Research Articles

Anion exchange extraction of tallium (III) and mercury (II) complex salts and application of the procedure to extraction-photometric determination of the microquantities of mercury (II)

The goal is to study the anion-exchange extraction of complex thallium (III) and mercury (II) halides (chlorides, bromides, iodides) by a method of a competing intermediate ion using the anions of various dyes — methyl orange, sodium picrate, 2,4-dinitrophenol, methyl red. Mercury (II) and thallium (III) are poisons of high toxicity. The developed method was used to study the anion-exchange extraction of acidocomplexes A solution of methyl orange trinonyloctadecylammonium (TNODA) in toluene was used as an extractant. The method provides determination of mercury (II) with an accuracy of ±2% when the concentration in the initial solution ranges within 2 – 8 × 10–8 mol/liter. It is shown that the values of the exchange constants for the same metal are larger for iodide complexes than for bromide and chloride ones. The extractability of metal halide complexes is mainly determined by their mass. Anions with a large mass have a large surface area, a low charge density, and are weakly hydrated, and thus are better extracted. The results of anion-exchange extraction were used to develop a procedure for the extraction-photometric determination of mercury (II) in granosan (ethylmercury chloride a prohibited insectofungicide of the 1st hazard class) the illegal use and storage of which could be a source of mercury pollution of groundwater in a number of regions of the Republic of Belarus. The relative error of determination does not exceed ±2%.

Complexometric determination of mercury(II) and thallium(III) using cysteamine hydrochloride as releasing agent

Complexometric determination of mercury(II) and thallium(III) using cysteamine hydrochloride as releasing agent

Structure and Bonding of Solvated Mercury(II) and Thallium(III) Dihalide and Dicyanide Complexes by XAFS Spectroscopic Measurements and Theoretical Calculations

Structure and Bonding of Solvated Mercury(II) and Thallium(III) Dihalide and Dicyanide Complexes by XAFS Spectroscopic Measurements and Theoretical Calculations

ChemInform Abstract: Corner Opening of Cyclopropanes by Mercury(II) and Thallium(III) and Transmetalation of the Intermediate Organomercurials. A Novel, Stereoselective Approach to Cyclobutanes and Cyclopropanes.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Corner opening of cyclopropanes by mercury(II) and thallium(III) and transmetalation of the intermediate organomercurials. A novel, stereoselective approach to cyclobutanes and cyclopropanes

The reactivity of the two isoelectronic cations (Hg2+ and T P ) toward the cyclopropane ring is compared, and further evidence for the exclusive corner selectivity for Hg2+ is provided by isotope labeling. Cleavage of cyclopropyl derivative 1 with Hg(NO3)2, followed by KBr quenching, afforded the stable, rearranged organomercurial 3, whose transmetalation has been studied. Whereas reaction of 3 with Pd(I1) afforded lactol 4, treatment with MezCuLi resulted in the formation of cyclobutanol derivative (3 - 29); analogous conjugate addition has also been accomplished (32 - 35). Similarly, the organomercurial 22, obtained from 21 as the major product on the Hg(I1)-mediated ringopening, reacted with MezCuLi or AlC13 to give the ring-closure product 21. These reactions representa novel method for the stereoselective construction of four- and three-membered rings. The stereochemistry of the key steps of these transformations has been established by using stereospecifically deuterated substrates lb, 3b, 21b, and 22b.

ChemInform Abstract: Metal Reagents in Organic Reactions. Part 6. Reactions of Pyridine and Quinoline Derivatives with Mercury(II) and Thallium(III) Acetates.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Mercury(II) and thallium(III) organometallic derivatives of 2-Mercaptobenzoxazole

Some derivatives of 2-mercaptobenzoxazole (HL) of the type MR nL [M = Hg or Tl, R = Me or Ph and n = 1 (Hg) or 2 (Tl)] have been prepared. The structure of HgMeL has been determined by an X-ray diffraction study; in the crystal there are two independent planar molecules in each asymmetric unit, with the ligand in its thiolic form and an almost linear CHgS linkage. Weak intramolecular and intermolecular secondary interactions complement the mercurysulphur bond. The spectroscopic (IR, Raman, mass, 13C-NMR), conductimetric, and dipolar properties of this and the other compounds are discussed.

ChemInform Abstract: Arene Activation with Mercury(II) and Thallium(III) Electrophiles. Mechanistic Relevance of Charge‐Transfer Transitions in π‐Complexes as Intermediates.

AbstractThe activation of various aromatic hydrocarbons (I) by mercuration and thallation proceeds via π‐complexes ((III) and (VII)) as observed by the transient CT absorption spectra.

Arene activation with mercury(II) and thallium(III) electrophiles. Mechanistic relevance of charge-transfer transitions in .pi.-complexes as intermediates

The activation of various aromatic hydrocarbons by mercuration and thallation proceeds via ..pi..-complexes, as observed by the transient charge-transfer (CT) absorption spectra. Quantitative spectrophotometric analysis of (a) the association constants K and 9b) the second-order rate constants k/sub 2/ establishes the reactive forms of the electrophiles to be Hg(O/sub 2/CCF/sub 3/)/sub 2/ and Tl(O/sub 2/CCF/sub 3/)/sub 2//sup +/, both in ..pi..-complex formation as well as in aromatic metalation. The direct participation by these isoelectronic and isostructural species presents a unique opportunity to examine arene activation with electrophiles which primarily differ only in the charge they bear. A detailed comparison of the CT excitation energies and the reactivities of various arenes relative to steric, kinetic isotope, and solvent effects in mercuration and thallation reveals unusual similarities. At the same time the observation of arene cations as key intermediates in thallation, but not in mercuration, leads to puzzling incongruities. The paradox is analyzed in the context of merging stepwise (electron-transfer) and concerted (electrophilic) mechanisms.

The behaviour of copper and thallium hexafluoromolybdates(V) in acetonitrile

Copper(I), copper(II), and thallium(III) hexafluoromolybdates(V), prepared by the oxidation of the metals in acetonitrile with molybdenum hexafluoride (A. Prescott, D.W.A.Sharp, and J.M. Winfield, J. Chem. Soc., Dalton Trans. , 1975, 963) have been investigated by cyclic voltametry. Half wave potentials, E 1 2 V vs. Ag p+/Ag were obtained using a evacuable cell equipped with anexternal Ag p+/Ag electrode, enabling strict anerobic conditions to be maintained. A number of reversible or quasi-reversible electron transfer processes have been observed, enabling comparison with synthetic work to be made. Results for Cu I and Cu II hexafluoromolybdates(V) are in accord with preparative experience. MoF 6. Mo VI/Mo VE 1 2 +1.600V, oxidises Cu metal to Cu II in MeCN, and Cu II is reduced by Cu O to Cu I , Cu lI/Cu IE 1 2 = +0.750 or +0.710V for Cu I and Cu II solutes respectively, Cu I/Cu OE 1 2 = −0.720V not reversible. A wave at E 1 2 = −0.350V is assigned to Mo V/Mo IV by analogy with Ag I hexafluoromolybdate (D.W.A. Sharp, unpublished work). E 1 2 data for I 2 in MeCN, I 2/I 3 - = 0.280, I 3 −/I − = -0.116V, suggest that reduction of MoF 6 − by I is not likely, in contrast to the situation in SO 2 (A.J. Edwards and R.D. Peacock, Chem. Ind. , 1960, 1441). Reduction of MoF 6 − by Cu o in MeCN should be feasible, but appears to be very slow. Pure Tλ III hexafluoromolybdate(V) is obtained from Tλ o and MoF 6 only when the mole ratio MoF 6:Tλ>5:1. Smaller ratios produce yellow solids in which Mo:Tλ is ca . 2:1. Tλ III is a stronger oxidising agent than Cu II in MeCN, as oxidation of Cu I by Tλ III is rapid and quantitative. However a reversible electron transfer wave assignable to Tλ III/Tλ I is not observed in the expected fange +1.600 to +0.710V possibly because of solute-electrode interactions.

Extraction of zinc thiocyanate complex by tributyl phosphate in benzene

The species extracted is shown to be Zn(SCN)X.2TBP, where X is a common anion. Good separation factors are obtained for extraction of zinc from solutions containing silver(I), manganese(II), cobalt(II), cadmium(II), mercury(II) and thallium(III).

Extraction of zinc and cadmium thiocyanate complexes in the presence of pyridine and some metal ion separations

Extraction of zinc(II) and cadmium(II) from ammonium thiocyanate solutions has been studied in benzene in the presence of pyridine. The effect of such variables as the pH of aqueous phase and concentration of metal, thiocyanate and pyridine on extraction has been investigated and the extracting species identified. Extraction behaviour of silver(I), manganese(II), cobalt(II), mercury(II) and thallium(III) has also been studied under identical conditions and some binary metal ion separations of analytical and radiochemical importance are reported.

ChemInform Abstract: MECHANISMS AND CATALYSIS IN VINYL ESTER HYDROLYSIS

Abstract A critical survey of literature concerning the catalysis, mechanisms, and kinetics in vinyl ester hydrolysis is presented together with new results. The relatively fast alkaline and acid-catalysed hydrolyses usually take place with acyl-oxygen fission. General base and nucleophilic catalyses are known. Appreciable neutral ester hydrolysis by general base catalysis of water occurs generally. The unsymmetrically acid-catalysed partition of the tetrahedral intermediate formed in the neutral hydrolysis has been found to lead to acid catalysis if the ester has electronegative substituents. Vinyl esters differ from other esters by the possible electrophilic addition to the double bond. Thus mercury(II) and thallium(III) ions catalyse the reaction, and acid catalysis takes place by ASE2 mechanism at high acidities or when the formed carbenium ion is structurally stabilized.

Mechanisms and catalysis in vinyl ester hydrolysis

Abstract

ChemInform Abstract: THE OXIDISING AND FLUORIDE ION ACCEPTOR PROPERTIES OF URANIUM HEXAFLUORIDE IN ACETONITRILE

AbstractMetallisches Cu, Cd und T1 werden durch UFÖ in Acetonitril bei Raumtemperatur zu Lösungen der Metall(II bzw. III)‐hexafluorouranate(II) oxidiert.

Mercury(II) and thallium(III)-induced aquations of some trans-chloropyridinebis(dimethylglyoximato)-cobalt(III) complexes

The second-order rate constants for mercury(II) and thallium(III)-induced aquations of trans-[Co(DH) 2(R-py)Cl] (DH = dimethylglyoximate ion, R-py = pyridine, 3-picoline and 3,5-lutidine) have been measured in 40% v/v ethanol solution over a range of temperatures. The inducing effects of Hg 2+ and Tl 3+ are found to be quite similar and the kinetic results are discussed in terms of the formation of an activated complex Co Cl M (M Hg 2+ or Tl 3+), followed by a simple rate determining aquation in which M Cl acts as the leaving group.

The oxidising and fluoride ion acceptor properties of uranium hexafluoride in acetonitrile

Metallic copper, cadmium, and thallium are oxidised by uranium hexafluoride in acetonitrile at ambient temperatures to give solutions of copper(II), cadmium(II), and thallium(III) hexafluorouranates(V). After removal of solvent, these salts were obtained as solvates. Copper(II) fluoride reacts with uranium hexafluoride in acetonitrile to give copper(II) heptafluorouranate(VI).

Mercury(II) and thallium(III)-induced aquations of trans-halogeno-amminebis(dimethylglyoximato)cobalt(III) complexes

Mercury(II) and thallium(III)-induced aquations of trans-halogeno-amminebis(dimethylglyoximato)cobalt(III) complexes

The uncatalysed and mercury(II)- and thallium(III)-catalysed elimination of chloride from the µ-amido-µ-chloro-bis[tetra-amminecobalt(III)] complex

The kinetics of the mercury(II)- and thallium(III)-catalysed elimination of chloride from the title complex (I), equation (i), have been studied in aqueous HClO4 solution, I= 2·0M(NaClO4). Both reactions are independent [graphic omitted] of [H+] in the range 0·5–2·0M. With mercury(II) there is a less than first-order dependence on [Hg2+] which cannot be satisfactorily accounted for in terms of a 1 :1 adduct. Instead the dependence can be explained by considering Hg2+-catalysed conversion of (II) into (III) and applying the steady-state approximation for (II). From the treatment (at 25 °C), k1= 3·02 × 10–3 s–1, ΔH‡1= 19·2 ± 0·5 kcal mol–1, ΔS‡1=–5·7 ±1·8 cal K–1 mol–1, and k2/k–1= 0·028. At 25 °C ratios k3/k2= 1·57 × 103 I mol–1 and k4/k2= 1·3 × 103 I mol–1 are measures of the effectiveness of Hg2+ and HgCl+ as catalysts for (II)→(III). Thallium(III) produces only a mild catalytic effect, a first-order dependence on [Tl3+] is observed, and k5/k2= 15 I mol–1 is a measure of the effectiveness of Tl3+ as a catalyst. It is concluded that Tl3+ is a relatively weaker catalyst compared to Hg2+ for (II)→(III) than for the catalysed aquation of mononuclear chloro-complexes.

Reduction by the triplet charge-transfer state of tris(bipyridyl)ruthenium(II). Photochemical reaction between tris(bipyridyl) ruthenium(II) and thallium(III)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTReduction by the triplet charge-transfer state of tris(bipyridyl)ruthenium(II). Photochemical reaction between tris(bipyridyl) ruthenium(II) and thallium(III)Gerald S. Laurence and Vincenzo. BalzaniCite this: Inorg. Chem. 1974, 13, 12, 2976–2982Publication Date (Print):December 1, 1974Publication History Published online1 May 2002Published inissue 1 December 1974https://doi.org/10.1021/ic50142a039RIGHTS & PERMISSIONSArticle Views207Altmetric-Citations56LEARN 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 (977 KB) Get e-Alerts Get e-Alerts