Thallium(I)

Ohne Zusammenfassung     

Thallium(I)-Uranates(VI)

The solid state preparation, thermal and hydrolytic characteristics of thallium(I)—uranates(VI) are described. The phases identified were Tl₂UO₄, Tl₂U₂O₇ and a range of solid solution (Tl₂O. 2,33 UO₃? Tl₂O. 6 UO₃). The thallium uranates are isostructural with the corresponding potassium uranates. Tl₂U₂O₇ is the stable phase formed from the other uranates on hydrolytic treatment. The thallium uranates lose thallium(I) oxide on heating to temperatures above 750°C and the order of thermal stability is Tl₂U₆O₁₉～Tl₂U₃O₁₀～Tl₂U₂O₇»Tl₂UO₄.     

Blei und Thallium(I)

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Thallium(I) -bis(trimethylsilyl) amid

The reaction of LiN(SiMe₃)₂ With TlCl in toluene yields the bis(trimethylsilyl)amino derivative of thallium(I) (1). In the gaseous phase and in benzene solution the compound is mainly monomeric, whereas in the solid state the amide 1 consists of cyclic dimers, which are linked to infinite chains by intermolecular Tl Tl contacts.     

Die Extraktion von Thallium(I)

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Thallium(I) Selective Solid Membrane Electrode

Abstract

Heterogeneous membranes of 2.0 cm diameter were prepared from a 60:40 mixture of thallium(I) molybdoarsenate and Araldite, These membranes gave near Nernstian response to thallium(I) ions over the concentration range 10^?1 to 10^?3M but could be used for determination of thallium(I) down to 10^?5M. Slope of the log concentration-potential plot is improved in 10 and 25 percent acetone-water mixture. The response was independent of pH over the range 4.0 to 6.0, The response time of the electrode is few seconds and potentials generated are reproducible. The selectivity of the electrode over a large number of cations was studied. The values of selectivity coefficients are of the order 10^?2 for monovalent and 10^?3 for bivalent cations. Anions did not interfere. Potentiometric-titration of thallium nitrate with potassium chromate was also done using the membrane as an end point indicator electrode.     

The Crystal Structures of Thallium(I) Fluoride

The effects of temperature and pressure on the crystal structures of thallium(I) fluoride have been investigated using powder neutron diffraction, with the aim of resolving the uncertainties present in the literature. Under ambient conditions, TlF adopts an orthorhombic structure in space group Pbcm with Z=4 and cell parameters a=6.09556(8) Å, b=5.48860(7) Å, and c=5.18300(7) Å. This structure can be derived from an idealized rocksalt-type arrangement, though with extensive distortions of the anion sublattice due to the presence of the 6s² inert pair of the Tl⁺ Above 355 K TlF becomes tetragonal with Z=2, a=3.78283(2) Å, c=6.12312(5) Å, and space group P4/nmm. The behavior of the compound is also studied under hydrostatic pressure but, contrary to previous reports, no structural transition was observed and TlF remains orthorhombic up to at least 3.5 GPa. The compressibility is greatest along the a and b axes. The relationship between the ambient- and high-temperature structures of TlF is described and the influence of the inert pair discussed in relation to the massicot structured polymorph of PbO.     

Dihalocarbenes Rrom Thallium (I) Ethoxide and Haloforms

It has been known for many years that dihalocarbenes may be generated by the reaction of strong bases with haloforms and that the resulting dihalocarbenes react rapidly with alkenes to produce dihalocyclopropane derivatives.¹ The procedures reported to date suffer from two disadvantages in that they require: 1) the use of a date solvent or the necessity of a two-phase system when a hydrocarbon solvent is used, and 2) the use of covalent nature and unique solubility properties of thallium (I) ethoxide suggested that its use might eliminate, or at least minimize, these diffculties in the generation of dichalocarbenes.     

Untersuchungen zur Struktur von Thallium(I)-halogenomercuraten(II)

Investigations on the Structure of Thallium(I) Halide Mercurates(II) Tl₄HgBr₆ crystallizes tetragonal with a = 8.978, c = 8.812 Å and Z = 2 in the space group P4/mnc. Singlecrystal methods revealed isolated HgBr₆-octahedra, compressed alonged the [001] axis, with thallium atoms between them. The results have been extended to clarify the structures of the isomorphous compounds (NH₄)₄HgBr₆ (a = 9.011, c = 8.660 Å), Tl₄HgJ₆ (a = 9.529, c = 9.387 Å) and Tl₄HgCl₂Br₄ (a = 8.896, c = 8.735 Å). It was impossible to obtain Tl₄HgCl₆; all attempts resulted in the formation of Tl₁₀Hg₃Cl₁₆, which crystallizes tetragonal (a = 8.477, c = 23.699 Å).     

Thermal Decomposition of Thallium(I) Bis-oxalatodiaquaindate(III) Monohydrate

Thallium(I) bis-oxalatodiaquaindate(III) monohydrate was obtained by precipitation of indium(III) withoxalic acid from slightly acidic solution in the presence of thallium(I). The complex was subjected to chemical analysis. The thermal decomposition behavior of the complex was studied using TG, DTA and DTG techniques. The solid complex salt and the intermediate product of its thermal decomposition were characterized using IR absorption and X-ray diffraction spectra. Based on data from these physicochemical investigations the structural formula of the complex was proposed as Tl[In (C₂O₄)₂ (H₂O)₂]⋅H₂O. This revised version was published online in August 2006 with corrections to the Cover Date.     

Kalium, Rubidium, Caesium und Thallium(I)

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Thallium(III)

Ohne Zusammenfassung     

205Tl-NMR-spektroskopische Untersuchungen an Thallium(I)-und Organothallium(III)-Verbindungen

Inhaltsübersicht. Mittels ²⁰⁵Tl-Breitlinien- und hochauflösender ¹H-NMR wurden Tl(I)-sowie Organothallium(III)-Verbindungen untersueht und ²⁰⁵Tl- und ¹H-chemische Verschiebungen sowie ²⁰⁵Tl-¹H-Kopplungskonstanten ermittelt. Die NMR-Parameter dor Tl(I)-Verbindungen wurden mit Literaturwerten verglichen. Die paramagnetischen ²⁰⁵Tl-Verschiebungen von Verbindungen des Type R₂TlX (R = Me, Et. n-Pr, Ph; X = NO₃, F, Br, J) werden in Bezug auf Substituenten., Losungsmittel- und Konzentrationseinflüsse diskutiert. Auf der Basis eines 0.3 molaren wäßrigen TINO₃-Primärstandards werden die ²⁰⁵Tl-Verschiebungen in einer einheitlichen Verschiebungsskala geordnet und nach bindungstheoretischen Gesichtspunkten verglichen. ²⁰⁵Tl-N.M.R.-Spectroscopical Studies on Thallium(I) and Organothallium(III) Compounds Abstract. Tl(I) and organothallium(III) compounds are investigated by means of ²⁰⁵Tl wide line and high resolution ¹H-n.m.r. and ¹H chemical shifts as well as ²⁰⁵Tl-²H coupling constants are estimated. The n.m.r.-parameters of the Tl(I) compounds are compared with the values of the literature. The paramagnetic ²⁰⁵Tl shifts of compounds of the type R₂TlX (R = Me. Et, n-Pr. Ph; X = NO₃, F, Br. I) are discussed with reference to the influence of substituents, solvents, and concentrations. The ²⁰⁵Tl shifts are arranged on the basis of a 0.3 M aqueous TlNO₃ primary standard in a uniform shift scale and compared as to theoretical aspects of chemical bonds. Für die großzügige Unterstützung unserer Arbeit danken wir Herrn Prof. Dr. K.-D. Schleinitz.     

Thallium(I) supramolecular compounds: Structural and properties consideration

During the last two decades, supramolecular compounds and especially coordination polymers have received great attention and the number of their synthesized compounds is still growing, which is mainly due to their potential application in various fields such as microelectronics, nonlinear optics, ion exchange, catalysis, gas storage, separation and luminescence. Formation of polymers with main group metal ions such as thallium(I) is disproportionately sparse when compared with those of other metals. Because of the interest structures, properties and applications of thallium polymers, it is necessary to understand thallium's ability to bind donors and form supramolecular compounds. This review tries to give an overview of all supramolecular compounds which were reported from thallium(I) after 1990 and to investigate their properties and applications. Thallium(I) usually forms neutral species and exhibits greater tendency to forming one-dimensional supramolecular compounds. Thallium(I) also favors secondary interactions on its coordination sphere (especially with unsaturated carbon atoms forms organometallic polymers) with stereochemically active lone pair and hemidirected coordination sphere around it.     

Optical Properties of Thallium(I) Perrhenate. Thallium-Localized Phosphorescence

Summary. The salt Tl⁺ReO₄ ^– shows a strong luminescence at _max=400nm which originates from the lowest-energy sp triplet of Tl⁺. A low-energy Tl^IRe^VII metal-to-metal charge transfer excited state has not been observed.     

Thallium(II) in the chemically induced thallium(I)-Thallium(III) exchange

The rate of the electron exchange between thallium(I) and thallium(III) induced by iron(II) has been measured at various concentrations of Tl(I), Tl(III), and Fe(II).²⁰⁴Tl tracer, initially in the Tl(I) state, was used. Exchange induced by the separation method was less than 0.01%. The mechanism earlier discussed is $$\begin{gathered} Tl^{III} + Fe^{II} \rightleftharpoons Tl^{II} + Fe^{III} \left( {k_1 ,k_{ - 1} } \right) \hfill \\ Tl^{II} + Fe^{II} \rightharpoonup Tl^I + Fe^{III} \left( {k_2 } \right) \hfill \\ *Tl^I + Tl^{II} \rightleftharpoons *Tl^{II} + Tl^I \left( {k_I } \right) \hfill \\ *Tl^{II} + Tl^{III} \rightleftharpoons *Tl^{III} + Tl^{II} \left( {k_{III} } \right), \hfill \\ \end{gathered} $$ which provides an exchange path in addition to the two-electron reaction^*Tl^I+Tl^III?^*Tl^III+Tl^I (k_ex). The rate law deduced from this mechanism agrees with experiment over a limited range of conditions but fails to account for the observed effect at low concentrations of Tl(I). The additional rate can be represented by inclusion of a term in which the rate of the induced exchange is independent of the concentration of Tl(I). When treated according to the resulting complete rate law the data are consistent with earlier photochemical studies. The present results in combination with other data give k₂=3·10⁶ M^?1·sec^?1 in 1M perchloric acid at 25°C. This is in satisfactory agreement with a recent pulse radiolysis measurement as well as with independent flash photolysis studies.