Thallium soluble compounds

The element and its compounds are toxic and should be handled carefully. Contact of the metal with skin is dangerous, and when melting the metal adequate ventilation should be provided. Exposure to thallium (soluble compounds) - skin, as Tl, should not exceed 0.1 mg/ms (8-hour time-weighted average - 40-hour work week). Thallium is suspected of carcinogenic potential for... 

Tetrabromoethane Tetraethylpyrophosphate Tetramethyl succinonitrile Thallium, soluble compounds Tin compounds, organic Toluene... 

THALLIUM, SOLUBLE COMPOUNDS (AS TU Tl Synonyms vary depending upon specific compound None hazardous Properties vary depeodiag upon specifk compound ... 

The 2003 ACGIH threshold limit valuetime-weighted average (TLV-TWA) for thallium and soluble compounds is O.lmg/m , as Tl, with a notation for skin absorption. 

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The American Conference of Governmental Industrial Hygienists threshold limit value, 8 h time-weighted average, for thallium (elemental and soluble compounds) is 0.1 mg m with a skin exposure warning. 

Thallium (Tl, at. mass 204.37) occurs in its compounds in the I and III oxidation states. Thallium(I) compounds are the more stable. Thallium(I) forms sparingly soluble compounds, white TlCl, yellow Til, and black TI2S, as well as thiosulphate and ammine complexes of low stability. Colourless Tl ions can exist only in strongly aeidic media since the brown hydroxide, Tl(OH)3, which has no amphoteric properties, is precipitated at pH values as low as 0.3. Thallium(ni) yields halide-, oxalate-, and tartrate complexes. T1(I) is oxidized to Tl(ni) only by powerful oxidants, e.g., Mn04 , aqueous Cl2, and aqueous Br2. 

THALLIUM, SOLUBLE OCMPOUNDS (as Tl) (Soluble thallium compounds have variable molecular formulas. The molecular formula for thallium is Tl. The molecular formula for thallium acetate is C2H3O2TI. The molecular formula for thallium iodide is ITl. Soluble thallium compounds have variable formula weights. The formula weight for thallium 204.37. The formula weights for thallium acetate and thallium iodide are 263.42 and 331.27 respectively.)... 

The compound is called diphenyliodonium hydroxide—a name which indicates its relation to ammonium, sulphonium, and phosphonium compounds. Diphenyliodonium hydroxide, like other strong bases, forms well characterized salts with acids, which resemble in solubility the analogous salts of thallium. The compound is of special interest as in it iodine, which under other circumstances is an acid-forming element, plays the part of a base-forming element. 

Tr and K+ have similar sizes they both form soluble carbonates and hydroxides. Thallium(I) compounds are very poisonous. 

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. 

Unlike boron, aluminum, gallium, and indium, thallium exists in both stable univalent (thaHous) and trivalent (thaUic) forms. There are numerous thaHous compounds, which are usually more stable than the corresponding thaUic compounds. The thaUium(I) ion resembles the alkaU metal ions and the silver ion in properties. In this respect, it forms a soluble, strongly basic hydroxide and a soluble carbonate, oxide, and cyanide like the alkaU metal ions. However, like the silver ion, it forms a very soluble fluoride, but the other haUdes are insoluble. Thallium (ITT) ion resembles aluminum, gallium, and indium ions in properties. 

The relative toxicities of thallium compounds depend on their solubHities and valence states. Soluble univalent thallium compounds, eg, thaHous sulfate, acetate, and carbonate, are especiaHy toxic. They are rapidly and completely absorbed from the gastrointestinal tract, skin peritoneal cavity, and sites of subcutaneous and intramuscular injection. Tb allium is also rapidly absorbed from the mucous membranes of the respiratory tract, mouth, and lungs foHowing inhalation of soluble thallium salts. Insoluble compounds, eg, thaHous sulfide and iodide, are poorly absorbed by any route and are less toxic. 

Thallium and its compounds (particularly soluble salts) can cause serious or fatal poisoning from accidental ingestion or external application. Acute symptoms are nausea, vomiting, diarrhea, weakness, pain in extremities, convulsions, and coma. Chronic effects are weakness, pain in extremities, and rapid loss of hair. Thallium and its compounds are listed under Federal toxics regulations. It is listed hy the US EPA as a priority pollutant metal in the environment. 

Reaction of the anion 21 with Cp or Cp metal fragments provides further metallocene-type complexes with a pendant phosphaferrocene side-chain. For example, the reaction of the thallium derivative T1 21 with [Cp RhCl2]2 yields the cationic pentamethylrhodocenium 24 as its chloride (Scheme 1.5.10). This is an interesting species because it is a chiral water-soluble P ligand. The chloride anion can be exchanged by PF,s to make the compound more soluble in organic solvents. 

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