Metals thallium

Production and Economic Aspects. Thallium is obtained commercially as a by-product in the roasting of zinc, copper, and lead ores. The thallium is collected in the flue dust in the form of oxide or sulfate with other by-product metals, eg, cadmium, indium, germanium, selenium, and tellurium. The thallium content of the flue dust is low and further enrichment steps are required. If the thallium compounds present are soluble, ie, as oxides or sulfates, direct leaching with water or dilute acid separates them from the other insoluble metals. Otherwise, the thallium compound is solubilized with oxidizing roasts, by sulfatization, or by treatment with alkaU. The thallium precipitates from these solutions as thaUium(I) chloride [7791 -12-0]. Electrolysis of the thaUium(I) sulfate [7446-18-6] solution affords thallium metal in high purity (5,6). The sulfate solution must be acidified with sulfuric acid to avoid cathodic separation of zinc and anodic deposition of thaUium(III) oxide [1314-32-5]. The metal deposited on the cathode is removed, kneaded into lumps, and dried. It is then compressed into blocks, melted under hydrogen, and cast into sticks. 

There is no evidence for the existence of thallic hydroxide addition of hydroxide to an aqueous solution of a T1(III) salt gives TI2O2 instead. ThaHous hydroxide can be isolated as yellow needles by the hydrolysis of thaHous ethoxide [20398-06-5] which is conveniendy prepared as a heavy oH by the oxygen oxidation of thallium metal in ethanol vapor. ThaHous hydroxide darkens at room temperature and decomposes to TI2O and H2O on warming. 

The amount of oxygen dissolved in a sample of water can be determined by using thallium metal containing a small amount of the isotope Tl-204. When excess thallium is added to oxygen-containing water, the following reaction occurs. 

After reaction, the activity of a 25.0-mL water sample is 745 counts per minute (cpm), caused by the presence of Tl+-204 ions. The activity of Tl-204 is 5.53 X 105 cpm per gram of thallium metal. Assuming that 02 is the limiting reactant in the above equation, calculate its concentration in moles per liter. 

Thallium phthalocyanine (PcT12) can be obtained by heating phthalonitrile with an inter-metallic alloy of indium and thallium in an evacuated glass ampule.145 The structure of this compound is unique among metal phthalocyanines as the two thallium cations occupy two opposite corners of an octahedron, which is formed by the thallium cations and the four iso-indolinc nitrogen atoms facing the center of the macrocycle.147 Another unusual type of phthalocyanine can be prepared by heating phthalonitrile with thallium metal.148 It was identified as a bicyclic thallium(III) phthalocyanine (Pc3/2T1).14S... 

The sulfide halides TISX are prepared by heating a stoichiometric mixture of the thallium halogenide and sulfur in a sealed ampoule at 180°C for 30 h. The mixture is then slowly cooled to room temperature. The compounds TlSeX are obtained by reaction between thallium metal and selenide halide at 280°C during 40 h (22). On heating TlYCl to 500°C in vacuo, the compounds TI4YCI4 result (322). Dissolution of... 

Uson, R., Laguna, A., Abad, J.A. and Dejesus, E. (1983) Preparation Of Monomeric Neutral Or Anionic Tris (Polyfluorophenyl)-Thalbum(III) And Of Anionic Heteronuclear Tris (Polyfluorophenyl)-Thallium Metal-Carbonyl-Complexes. Journal of the Chemical Society, Dalton Transactions, (6), 1127-1130. 

Thallium metal, 24 627—629 Thallium nitrates, 24 633 Thallium organometallics, 24 633—635 Thallium oxides, 24 632—633 Thallium poisonings, 24 637, 638-639 Thallium stress test, 24 629 Thallium sulfates, 24 628, 633 Thaumatin, 72 43, 24 241-242 Thaumatin II, 24 242 Theaspiranes, 24 572 Thebaine, 2 89 Thenardite, 22 863, 5 785t Thenoyltrifluoroacetone molecular formula, 5 712t Theobroma cacao, 6 350 Theobromine, 2 105-106... 

Elemental thallium metal is rare in nature mainly because it oxidizes if exposed to air (oxygen) and water vapor, forming thallium oxide, a black powder. Although some compounds of thallium are both toxic and carcinogenic, they have some uses in the field of medicine. Some compounds have the ability to alter their electrical conductivity when exposed to infrared light. 

Elemental composition T185.22%, Cl 14.78%. A smaU amount of the salt is dissolved in water (it is shghtly soluble in water at room temperature) and the solution analyzed for chloride ion by ion chromatography or by titration with a standard solution of silver nitrate using potassium chromate indicator. The salt is digested with nitric acid, diluted, and analyzed for thallium metal by... 

Thallium nitrate is prepared by reacting thallium metal, thaUous oxide, TbO or thaUous hydroxide, TlOH, with nitric acid followed by crystallization ... 

Although Lamy claimed that Sir William Crookes s thallium was really a sulfide, the latter replied that he had prepared metallic thallium as early as May 1, 1862, but that because of its volatility he had not dared to melt the black powder to form an ingot (18). However, a committee from the French Academy, including Henri Sainte-Claire Deville, Theophile-Jules Pelouze, and J.-B.-A. Dumas, credited Lamy, rather than Crookes, with the isolation of thallium metal (17, 40). 

Caution. Compounds of thallium and thallium metal are extremely poisonous. Protective rubber gloves should be used in handling thallium compounds and their solutions, and all operations should be carried out in a well-ventilated fume hood. Disposal of thallium and mercury-containing residues must be handled according to procedures established for poisonous metals. 

SRM 979), Ni (nickel metal isotopic standard NIST SRM 986), Rb (rubidium chloride isotopic standard NIST SRM 984) and Sr (strontium carbonate isotopic standard NIST SRM 987). In addition, isotope reference materials are available for heavy elements such as T1 (thallium metal isotopic standard NIST SRM 997), Pb (NIST lead standard reference materials SRM 981-983) or U (uranium oxide NIST isotope standard U 005, U020, U350, U500 or U930) and others. The most important isotope standard reference materials applied in inorganic mass spectrometry are summarized in the table in Appendix V.17... 

Thallium metal is bluish-gray upon fresh exposure, changing to dark gray on standing, this oxidation increased with temperature above 25°C soft, and may be easily cut with a knife. It is malleable but of low tenacity, so that it must be extruded to form wire HNO3 is the best solvent forms alloys with many metals, e.g., mercury, cadmium, zinc, silver, copper, magnesium,... 

For the recoveiy of thallium from the flue dust of pyrite burners, the dust is boiled with H2O, allowed to stand some time, filtered, and HC1 added to die filtrate, whereupon crude thallous chloride is precipitated. This is purified by further treatment, and thallium metal obtained (1) by electrolysis of the sulfate solution or (2) by fusion of the chloride widi sodium cyanide and carbonate. 

B. Reaction of a Thallium Metal Carbonylate with a Silicon Halide. .. 11... 

Thallium — Metal (atomic weight 204.383 gmol-1) found in nature mostly associated with minerals of copper, zinc, lead, and iron. Industrial production is based on electrolytic reduction from solutions of thallium in sulfuric acid obtained by dissolution of dust and cementation residues generated during lead and zinc production. 

VII.2 THALLIUM, T1 (Ar 204-34) - THALLIUM Thallium is a heavy metal with characteristics reminiscent of lead. It melts at 3023°C. Thallium metal can be dissolved readily in nitric acid it is insoluble in hydrochloric acid. 

Recently, the formation, structure, equilibrium, and kinetics of a family of cyano compounds containing a direct and not supported by ligands platinum-thallium metal-metal bond have been reported. The complexes are synthesized according to the reaction ... 

The reaction of trimethyl- or triethylthallium with Et3MH (M = Si, Ge), B10H14, or M H(CO)3Cp (M = Mo, W) leads to the formation of the thallium-metal bonded compounds Tl(MEt3), [Me2Tl][Me2Tl(BioHi2)], andMe2Tl(M (CO)3Cp), respectively. ... 

During the synthesis of HC[SiMe2N(Tl)t-Bu]3, competing redox processes lead to the precipitation of thallium metal and the formation of [HC SiMe2N(H)t-Bu SiMe2N(Tl)t-Bu 2] (123). ... 

The full potential of this highly reactive thallium metal has not been examined and it is expected that it will prove to be of value in many reactions. 

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