Ion thallium

The dc polarogram of the mixture containing the above-mentioned metal ions shows distinct steps corresponding to T1(I), Cd(II), Zn(II), and Co(II) ions only (Fig. 18) but does not provide information about the presence of the other three ions, viz., lead, indium, and nickel, in the mixture. Further, the limiting current corresponding to each step seems to be due to a combined concentration effect of lead and thallium ions, cadmium and indium ions, and zinc and nickel ions. 

The ac polarograms of the mixture at varying frequencies (Fig. 19) shows four ac summit peaks corresponding to reduction of T1(I), In(III), Cd(II), and Zn(II). The summit peaks for In(III) and Cd(II) are very close and so their ac waves are not very sharp. The first summit peak corresponding to T1(I) appears to be due to the combined reduction of lead and thallium ions, as is evident from the summit peak height. Hence, ac polarographic analysis only enables the identification of four metal ions out of seven and... 

The thallium salts 153 are stable to moisture and oxygen both in solution and in the solid state. X-ray crystallography of 153a (R = Ph) revealed a significant separation between the thallium ion and the anionic borate counteranion (B-Tl distance is equal to 425.3 pm) <2001CC2152>. 

M. Zadronecki, I. A. Linek, J. Stroka, P.K. Wrona, and Z. Gajus, High affinity of thallium ions to copper hexacyanoferrate films. J. Electrochem. Soc. 148, E348-E355 (2001). 

H. Kahlert, S. Komorsky-Lovric, M. Hermes, and F. Scholz, Prussian blue-based reactive electrode (reactrode) for the determination of thallium ions. Fresenius J. Anal. Chem. 356, 204-208 (1996). 

The effect of bath additives on the electrocodeposition of alumina-copper has been studied. Chloride ion was found to significantly inhibit incorporation of alpha alumina in an acidic copper bath [27, 51], whereas thallium ions, cesium ions, and tetra-ethylene pentamine were promoters [25, 32]. 

Thallium(I) acetate, 24 630-632 Thallium compounds, in organic reactions, 24 635 Thallium formate, 24 630 Thallium halides, 24 632 Thallium ion, 24 629 Thallium nitrate, uses for, 24 636 Thallium salts, 24 630, 632 Thallium sulfate, uses for, 24 636 Thallium (III) compounds, in organic reactions, 24 635-636 Thallium(III) fluoride, 24 632 Thallium(III) ion, 24 630 Thallium(III) salts, 24 632 Thallium(III) trifluoroacetate, 24 635 Thallium (Tl), 24 627-641... 

Thallium(i) salts have long been used in reactions with organic and organometallic halide complexes as a means of activating the halide by removal as insoluble T1X. However, the thallium ions proved not to be innocent bystanders, and numerous examples were reported in COMC (1995) where the metal-bound thallium complexes were formed. Deliberate reactions of thallium(i) and thallium(m) salts with metal carbonyl anions have yielded a variety of complexes of the form T1 MLJ3. In the past decade, new examples of metal carbonyl derivatives of thallium have been prepared (see Table 2). In addition, the propensity for Tl+ to form adducts with 16-electron noble metal complexes has been exploited. 

The related reaction shown in Equation (104)117 leads to a butterfly arrangement with two thallium ions bridging between two gold atoms, 127. Here, the Tl-Tl distance is 360.27 pm and is thought to contribute significantly to the physical properties of the complex. The compound shows solvent-dependent luminescent behavior in solution as well as in the solid state. 

Association constants for salts of copper, silver, and thallium appear to reflect solvation in a fairly simple way. For example, of the perchlorate salts, only those of the poorly solvated thallium ion show association. 

We will use the example of thallium ion. The potential of the working electrode will be stepped from a potential at which only Tl" " is the stable form to a potential at which only is the stable form. Figure 6.2(a) shows a plot of potential against time - note that the rise in potential here is essentially vertical. It would be completely vertical but for the requirement to charge the doublelayer around the electrode. The potential before the step is, e.g. 0 V, i.e. it is well cathodic (negative) of, .,+(= 1.252 V), so Tl is the only stable redox form, and no Tl " " will form. Thie potential after the step is, e.g. 1.6 V, i.e. it is well anodic of 3+. p,+, so Tl is the only stable redox form here, thus causing Tl" to oxidize to Tl +. 

The value of[Tl ] in the solution bulk remains essentially constant since only a tiny proportion of the overall amount of Tl is oxidized, but at the surface of the electrode we can say, to a good approximation, that [Tt ] = 0. Very soon after the potential is stepped, Tl from the bulk diffuses toward the electrode, thereby attempting to even out the concentration gradient, i.e. to replenish the Tt" that was consumed at the commencement of the step. W need to recognize, however, that these thallium ions will not remain as Tl for long as they will be oxidized immediately to form Tl, i.e. as soon as they impinge on the electrode. The end result is that a concentration gradient will soon form after the potential has been stepped. 

Prussian yellow. This irreversible binding of thallium(I) ions is probably related to the well-known use of Prussian blue to bind thallium ions following poisoning. 

An example of a channel- or pore-forming antibiotic is gramicidin A (9.57), a peptide consisting of 15 amino acids. It induces the transmembrane transport of protons, alkali-metal ions, and thallium ions at concentrations as low as 10 ° M, even though it is unable to complex these ions in solution. Gramicidin also forms several dimers with itself. 

Among some metal oxygen compounds which add, palladium and thallium ion both oxidize olefins and apparently the initial step is the addition of a metal hydroxide across the olefin double bond. The intermediates have not been isolated because they go on to other products but kinetic and other evidence indicates that the addition of the hydroxide is the initial step. In the well known mercury acetate addition to olefins in alcohol solution one can isolate the /S-hydroxv or alkoxy ethylmercury derivatives. 

A), while the second thallium ion is three-coordinate with an additional interaction with the pyridyl nitrogen atom (Tl—N distance is 2.468(15) A). The metal-metal interaction occurs between the three-coordinate thallium ion of one molecule and the two-coordinate thallium ion of a neighbouring dimer. 

Blue pigment salts are also used as an effective antidote for thallium intoxications. Ferric cyanoferrate interferes with the enterosystemic circulation of thallium ions and enhances their fecal excretion [3.221],... 

The structure of and possible cation location in these materials is fairly well known (2, 8, 4, )> and their ion-exchange behavior toward a multitude of pairs of ions, mostly including sodium, has been measured and interpreted in terms of basic properties of ions, crystal structures, and pore dimensions. The major part of these studies is with alkali- and alkaline-earth cations, alkylammonium ions, rare-earth cations, and silver and thallium ions (1). In contrast, the ion adsorption of transition metals in faujasite has received little attention. 

Thallium forms the monovalent thallium and trivalent thallium(III) ions, the former being of greater analytical importance. Thallium(III) ions are less frequently encountered in solutions, as they tend to hydrolyse in aqueous solution, forming thallium(III) hydroxide precipitate. Thallium ions can be... 

The versatility of the thallium ion, its coordination number and its geometry are responsible for many properties and, in particular, for the use of Tl(I)-/3-diketonato complexes as... 

Fluorescent hydrophobes (naphthyl and pyrenyl groups) incorporated into the polysulfobetaines are a powerful tool for studying the formation of intra-and interpolymer aggregates in aqueous and aqueous salt solutions [85,229-231]. Intermacromolecular hydrophobic association is observed as an increase in the excimer emission relative to that of the monomer emission, where h/Iu is the ratio of intensities of excimer and monomer fluorescence which reflects the extent of inter/intra macromolecular interactions. Intramolecular micellization is easily monitored by the quenching efficiency of the thallium ions. The decrease of h/Iu reflects the breaking of the intra- and interchain associations in aqueous salt solutions, leading to chain expansion. 

Using thallium—sodium zeolites of type X (n = 2.30), we observed an increase of adsorption capacity for water vapor and benzene at 38% replacement of sodium ions by thallium ions, and then its decrease with an increase in the degree of exchange. As thallium ions replace sodium ions in the position Sm (25) we may assume redistribution of cations at dehydration under the conditions of high vacuum and thermal treatment at 350°C, and stronger chemical bonds of thallium atoms in screened positions in comparison with sodium atoms. 

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