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.     

Synthesis and Characterization of a New Thallium(I) Coordination Polymer of Tetrazolate Ligand as Precursor for Preparation of Thallium(III) Oxide Nanoparticles

A new thallium(I) coordination polymer, [Tl₂L · H₂O]_n ( 1 ) [H₂L = 5‐(4‐hydroxyphenyl)tetrazole], was synthesized and characterized by IR spectroscopy, elemental analysis, and X‐ray crystallography. The single‐crystal X‐ray diffraction data of compound 1 show the existence of two different Tl^I ions with differing coordination numbers. The coordination number of Tl^I(1) is four and that of Tl^I(2) is two. This coordination polymer was used as a precursor for the preparation of Tl^III oxide nanoparticles. Thallium(III) oxide was characterized by powder X‐ray diffraction and the morphology of nanoparticles characterized by scanning electron microscope (SEM).     

A thallium(I) tetranuclear cubic cage unit in an interpenetrated supramolecular polymer: A new precursor for the preparation of Tl2O3 nanostructures

A new thallium(I) supramolecular polymer, [Tl₄(μ₃-4-BN)₄]_n (1) [9-HBN = 4-hydroxy benzonitrile], with a disordered cubic cage structural unit has been synthesized and characterized. The single-crystal X-ray data of compound 1 shows one type of Tl^I ion in the tetranuclear cubic cage structure with a coordination number of three. In addition to two intra cage thallophilic interactions in 1, each thallium(I) atom has a weak Tl?N secondary interaction with the nitrile group of the 4-BN⁻ ligand. Finally the Tl-ions attain the O₃Tl?NTl₂ coordination sphere with a stereo-chemically ‘active’ electron lone pair on the metal. The self assembly between the benzonitrile groups of one cubic cage structure with an adjacent one with a Tl?N short contact, by π-π stacking and weak hydrogen bonding interactions, results in the formation of a new interpenetrating thallium(I) supramolecular polymer. The thermal stability of 1 was studied by thermo gravimetric (TG) and differential thermal analyses (DTA). Nanostructures of thallium(III) oxide were prepared from a calcination process of compound 1 fine powder at 743 K. These nanostructures were characterized by X-ray powder diffraction (XRD) and scanning electron microscopy (SEM).     

Thallates of alkali metals and monovalent thallium formed in aqueous solutions of their hydroxides

Conclusions As a result of an investigation of the heterogeneous equilibria in M₂O-Tl₂O₃-H₂O systems, where M=Tl(I), Li, Na, K, Rb, and Cs, at 25°C it was established that the components only react in systems with thallium(I) and sodium hydroxides with the formation of thallium(I) orthothallate and restricted solid solutions between thallium oxide and the orthothallate based on thallium oxide and sodium hydroxythallate Na₃Tl(OH)₆, respectively.At elevated temperatures of 150 and 200°C it was established that potassium metathallate is formed in the K₂O-Tl₂O₃-H₂O system while sodium metathallate NaTlO₂ and a hydrated thallate of the composition 4Na₂O·Tl₂O₃·(3–4)H₂O are formed in the Na₂O-Tl₂O₃-H₂O system at 150°C. The thallates Tl₃TlO₃, Na₃Tl(OH)₆, NaTlO₂, and KTlO₂ have been isolated in a pure form and identified.The amphoteric nature of thallium oxide has been proven.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1689–1693, August, 1984.     

Die Kristallstruktur des Thallium(I)-hexaiodomercurat(II), Tl4Hgl6

Crystal Structure of Thallium(I) Hexaiodomercurate(II), Tl₄HgI₆ In the structure of the tetragonal Tl₄HgI₆ (a = 944.6 pm, c = 926.0 pm, Z = 2, space group P 4/mnc) isolated, in c-direction compressed HgI₆ octahedra are situated. The mercury atoms are disordered; they occupy statistically 4 positions in the equatorial plane of the octahedra in such a manner that strongly deformed HgI₄ tetrahedra are produced. The thallium atoms are eightfold coordinated like a bicapped trigonal prism. The relationship between the Tl₄HgI₆ structure and the cubical K₂PtCl₆ type will be discussed.     

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).     

Studies with dithizone : Part 26. The interaction of thallium(III) with solutions of dithizone in organic solvents

The strong oxidising capacity of thallium(III) dominates its reaction with solutions of dithizone (H₂Dz) in organic solvents. When carbon tetrachloride is used as solvent, the unstable thallium(III) complex Tl(HDz)³ is found in the organic phase but it very quickly disproportionates to the thallium(I) complex [Tl(HDz)], and bis-1,5-diphenylformazan-3-yl-disulphide. This reaction is notably faster in chloroform, in which thallium(I) dithizonate is the first identifiable product. In contact with an acidic aqueous phase, thallium(I) dithizonate is reverted to regenerate dithizone in the organic phase and Tl⁺ ions appear in the aqueous phase. Organic solutions of the disulphide disproportionate spontaneously by first-order kinetics to give an equimolar mixture of dithizone and the mesoionic compound, 2,3-diphenyl-2,3-dihydrotetrazolium-5-thiolate: this change is much slower in carbon tetrachloride than in the more polar chloroform and is catalysed by both Tl⁺ and Tl³⁺. If thallium(III) is present in excess, the mesoionic compound is the principal oxidation product of the dithizone although a dication may also be formed. The mesoionic compound does not react with thallium(I) but forms a water-soluble 2:1 complex with thallium(III); partition of this complex into the organic phase is uninfluenced by chloride ions. Because of the large number of competing reactions, the composition of the reaction mixture at any stage of the reaction between thallium(III) and dithizone depends on the relative concentrations of the components, the order in which they are brought together, the time elapsed after mixing, the pH of the aqueous phase, and the nature of the organic solvent.     

Conductivity and Raman spectroscopy of new indium(I) and thallium(I) ionic conductors. In4CdI6, In2ZnI4, and Tl2ZnI4, and the related compound Tl4CdI6

The new compound Tl₂ZnI₄ has been prepared and characterized by Raman spectroscopy, powder X-ray diffraction, elemental analyses, and a partial binary phase diagram. The compounds In₄CdI₆, Tl₄CdI₆, and In₂ZnI₄, for which phase diagrams are available in the literature, were characterized by Raman spectroscopy and their identities were confirmed by elemental analyses and X-ray powder diffraction. Each of these materials, except Tl₄CdI₆, undergoes a sharp order-disorder phase transition at elevated temperatures that can be detected by the measurement of Raman spectra as a function of temperature. Conductivity measurements as a function of temperature, using both reversible and blocking electrodes, reveal a high ionic conductivity in the disordered, high-temperature phase. This work suggests that indium(I) and thallium(I) ionic conductors may exist, analogous to some well-known double salt conductors based on simple silver(I) and copper(I) halides. In addition, the present study demonstrates the usefulness of Raman spectroscopy in the characterization of heavy-metal ionic conductors.     

Structure Cristalline du Sulfure d'Étain(II) et de Thallium(I) Tl2Sn2S3

Crystal Structure of Tl₂Sn₂S₃ The compound Tl₂Sn₂S₃ had been prepared from SnS? Tl₂S mixtures. The cell is monoclinic, space group C2/c with a = 13.887(7), b = 7.742(4), c = 7.267(4) Å, β = 105.39(3)° and Z = 4. The structure was solved by the symbolic addition method and refined by least-squares to a final R = 0.086 for the 382 observed reflections. From this structure it is apparent that Tl₂Sn₂S₃ is of defect NaCl type with the thallium and tin atoms distributed over the cation positions, the sulfur atoms and vacancies over the anion positions. Tl and Sn atoms have four bonds to S atoms of 2.81–3.13 Å and 2.68–3.11 Å respectively. The thallium and tin lone pairs of electrons are stereochemically active.     

Diagramme de phases du système Tl2OMoO3

Six thallium(I) molybdates with numerous allotropic modifications have been found in the binary system Tl₂OMoO₃; Tl₄MoO₅, Tl₂Mo₂O₇, Tl₈Mo₁₀O₃₄ (three forms), and Tl₂Mo₇O₂₂ (two forms) melt incongruently; Tl₂MoO₄ and Tl₂Mo₄O₁₃ which are trimorphic melt congruently. For the most part, the compounds were characterized by their powder diagram and by their IR spectrum which allowed comparisons with alkaline molybdates.     

Correlation between the covalency and the thallium-205 nuclear magnetic resonance chemical shift in oxides and halides

²⁰⁵Tl chemical shift measurements were carried out on thallium(I) oxides and halides. A correlation between the chemical shift and the stereochemical activity of the 6s² lone pair of Tl^I was established; the greater this activity, the greater the absolute value of the chemical shift. For the halides, optical and chemical shift measurements gave access to the Tl-X bond ionicity via Ramsey's equation. In thallium(I) halides the absolute value of the chemical shift increases with the covalency. The work of Glaser on thallium(III) halides showed the chemical shift to decrease with increasing covalency. An explication of this difference is proposed. The hyperfine coupling constant A of the paramagnetic compound Tl₄MnI₆ was determined by the study of the chemical shift as a function of the susceptibility. This constant A is seen to be weak (−7 KG/μ_B).     

Structure cristalline du metatitanate de thallium Tl2TiO3

A thallium titanate oxide Tl₂TiO₃ has been prepared. It is orthorhombic, space groupPnam, with unit cell dimensions a = 12.41 A?,b = 9.615 A?,c = 3.752 A?. The structure contains double chains of edge sharing TiO₅ trigonal bipyramids, in the z direction. In this compound, thallium I has a stereochemically active lone pair. There are four oxygens bonded to thallium, all to one side.     

Non-centrosymmetric coordination polymers based on thallium and acetylenedicarboxylate

Single crystals of anhydrous thallium acetylenedicarboxylate (Tl₂(C₄O₄), 1) and thallium acetylenedicarboxylate oxalate (Tl₄(C₄O₄)(C₂O₄), 2) precipitated from aqueous solutions containing thallium(I)-acetate and the respective organic acids. Both compounds crystallize in non-centrosymmetric space groups (1: P2₁2₁2₁; 2: C2) and contain stereochemically active lone pairs at Tl(I). The crystal structures of 1 and 2 show some similarities. Tl atoms are organized in corrugated layers, which are connected by the respective carboxylate anions. Upon heating 1 decomposes at 195 °C to form elemental pyrophorous thallium powder. 2 starts decomposing at approx. 150 °C forming elemental thallium next to another compound, which could not be identified up to now. TlHADC was also synthesized, but its crystal structure could not be solved either from powder or single crystal diffraction data. Upon heating it decomposes to form 1.     

Two-dimensional thallium(I) supramolecular polymer constructed from Tl?π interactions: A new precursor for the preparation of thallium(III) oxide with a nano-structural surface

A new two-dimensional thallium(I) supramolecular polymer, [Tl₂(μ₃-9-Ac)(μ₄-9-Ac)(H₂O)]_n (1) [9-HAc = 9-anthracene carboxylic acid]_, has been synthesized and characterized. The single-crystal X-ray data of compound 1 shows two types of Tl^I ions with coordination numbers of four and five. The thallium atoms have irregular coordination spheres, containing a stereo-chemically active lone pair with η⁵ Tl?C interactions in the vacant coordination sphere of the Tl^I ions, thus attaining total hapticities of 9 and 10 with O₅Tl1?C₅ and O₄Tl2?C₅ environments and Tl?π_(centroid) distances of 3.308 and 3.251 Å, respectively. The thermal stability of 1 was studied by thermo gravimetric (TG) and differential thermal analyses (DTA). Different morphologies of thallium(III) oxide with a nano-structural surface were prepared from compound 1 powders and compound 1 micro-rods. These nano-structures were characterized by X-ray powder diffraction (XRD) and scanning electron microscopy (SEM).     

A secondary ion mass spectrometric study of thallium oxide thin films grown via metal organic chemical vapour deposition

Within a comprehensive programme including synthesis via metal organic chemical vapour deposition (MOCVD) and characterization of inorganic compounds and materials of possible interest in technologies based on thin films, results concerning the deposition of metal oxides by means of volatile organometal precursors are reported. In particular, thallium oxide films obtained by the MOCVD technique and commercial powders of Tl₂O₃ and Tl₂O adsorbed on several metal substrates (stainless steel, Si, Cu, Mo, Pt) were studied by secondary ion mass Spectrometry (SIMS) under ion beam bombardment at different ion energies. The positive- and negative-ion mass spectra exhibit typical isotopic patterns of several ionic species produced by interesting interfacial reactions, and the analysis of their relative abundances provides a measure of oxide reactivity towards different substrates. SIMS measurements of metal substrates were also performed. The ability and limits of SIMS in the reactivity study of thallium oxide powders and films and, in addition, in the identification of reaction products evidencing impurity species that, in turn, can be ascribed to the substrates or to the precursors used for the oxide synthesis is pointed out.     

Heterogeneous equilibrium between solution and slightly soluble compound in flow injection analysis: Platinum(IV) determination

Summary A new principle of flow injection analysis using a precipitation reaction is suggested. It is based on a change of the equilibrium between solution and slightly soluble compound when passing the solution studied through a reaction column, containing a slightly soluble compound. H₂PtCl₆ is determined with a column containing Tl₂PtCl₆. The detection is performed by the current of thallium(I) oxidation to thallium(III) on a platinum electrode. Two different flow injection schemes are used. The determination of platinum(IV) is applied to platinum analysis in spent industrial alumoplatinum catalysts.     

Some studies on thallium oxalates. VI

The effect of the thallium(I) concentration on the potentiometric titration of thallium(III) with oxalic acid in 0.1M HNO₃ or 0.05M H₂SO₄ is studied, and conditions are established for the preparation of the thallium(I) bis-oxalato diaquo thallate(III) complex. Chemical analysis of the salt corresponds to the formula T1^I(T1^III(C₂O₄)₂) · 5 H₂O. Thermal decomposition studies on the complex using TG, DTG and DTA techniques indicate the formation of thallium(I) oxalate (stable from 130° to 320°) as the intermediate, the final product being a mixture of thallium(I) oxide and thallium(III) oxide (stable from 520° to 600°). Infrared absorption spectra, X-ray diffraction patterns and microscopic observations are used to characterise the complex and the intermediate.     

Synthesis and Crystal Structure of the First Thallium Hydrous Nesosilicate Tl4SiO4·0.5H2O

Orange prismatic crystals of the first thallium hydrous nesosilicate Tl₄SiO₄·0.5H₂O have been obtained by evaporation from aqueous solution. There are three symmetrically independent Tl⁺ cations and five symmetrically independent oxygen atoms in the structure of Tl₄SiO₄·0.5H₂O. The O(4) and O(5) atoms belong to water molecules. Coordination polyhedra of the Tl⁺ cations are strongly distorted because of the stereoactive behavior of lone electron pairs. The structure of Tl₄SiO₄·0.5H₂O contains sheets of SiO₄ tetrahedra and Tl coordination polyhedra. The sheets have the composition [Tl₃SiO₄]^– and are parallel to [100]. Within the sheets, SiO₄ tetrahedra link to thallium polyhedra though common corners. The sheets are linked by dimers of face‐sharing Tl(3)O₅ polyhedra, thus providing interconnection of the sheets into a framework. The framework has large elliptical channels occupied by water molecules (OW2) and electron pairs of Tl⁺ cations.The comparison with some other M⁺ (M = K, Ag, Tl) silicates is given.     

Radiation induced stabilization of unusual oxidation states in Tl (I) Ln (III) (SO4)2.4H2O (Ln=Sm,Eu and Nd): EPR investigations

Double sulfates of thallium and lanthanides form an interesting series of compounds with first fractional crystallization leading to the formation of tetrahydrated double sulfates. The radiation induced defects including changes in the oxidation states were studied by carrying out EPR investigations of -irradiated Tl (I) Ln (III) (SO₄)₂.4H₂O (Ln=Sm, Eu and Nd) compounds. The important finding of these investigations is the formation of a radiation-induced paramagnetic center Tl²⁺ simultaneously with that of Eu²⁺, revealing their intrinsic association. Similar formation of Tl²⁺ was not observed in other rare earth salts, implying that the stability of the half-filled electronic configuration of Eu²⁺ may be responsible for the stabilization of Tl²⁺. Their relaxation back to Eu³⁺ and Tl⁺ simultaneously at 255 K gives further confirmation of their association and suggests that the matrix intrinsically does not favor the stabilization of Eu²⁺ as reported in a number of other matrices. The hyperfine coupling constant for Tl²⁺ was calculated using the Breit-Rabi equation and was found to be 80 GHz.     

The trigonal–bipyramidal triiodo­thallium(III) complex [TlI3{(CH3)2SO}2]

The title compound, bis(dimethyl sulfoxide)triiodo­thallium(III), [TlI₃(C₂H₆OS)₂], was crystallized from equimolar amounts of Tl^II and I₂ in a dimethyl sulfoxide (DMSO) solution. After the initial redox reaction, the thallium(III)–iodo complex forms and precipitates as a DMSO solvate. In the crystal structure, Tl is surrounded by three iodide ligands in the equatorial plane and two O‐coordinated DMSO mol­ecules in the axial positions, forming a slightly distorted trigonal bipyramid. The complex lies on a twofold rotation axis, making the DMSO mol­ecules and two of the I atoms crystallographically equivalent.