Compounds thallium containing

Crystal growth of these compounds is complicated by the high volatility of thallium oxides and thallium-containing compounds at elevated temperatures and the toxicity of thallium. Also, the similarity in structures leads to problems controlling phase purity and samples which appear to be single crystals based on their morphology can be shown to be complicated intergrowths by X-ray diffraction studies. 

Caution. Compounds of thallium are toxic. This procedure should be carried out in a well-ventilated hood protective gloves should be worn to avoid any contact with thallium compounds. Residues containing thallium compounds must be disposed of in accordance to toxic waste disposal procedures. 

The term organometallic refer to compounds that contain a carbon-metal bond. [59] The term spans compounds that are primarily ionic (such as when the metal is sodium or potassium and thus should be nomenclated as the distinct ions) through compounds that are primarily covalent (such as when the metal is lead, tin, mercury or thallium for which the bonding is covalent)... 

Organothallium compounds are now known in oxidation states +1, +2 (silyl ligands), and +3. Several review articles dealing with the organometallic chemistry of thallium are available. This article is essentially limited to organothallium compounds that contain at least one Tl bond. 

Most of the compounds discussed contain boron, although studies involving A1 and Ga have increased. Little indium and thallium chemistry is known, presumably owing to the rarity of the former and the toxicity of the latter. This... 

Thallium oxide, TI2O, is an extremely useful material for employment in solar cells and electrical contacts [92]. The interest in thallium oxide has been spurred further by the discovery of thallium-containing superconducting metal oxides [93] (see Chapter 2). Compounds used for the preparation of thallium oxide by CVD include thallium(l) acetylacetonate, (Tl(acac) acac" 6), dimethylthallium acetylacetonate, (CH3)2T1 (acac), and cyclopentadienyl thallium(i), CpTl (13). These precursors decompose in the presence of oxygen at temperatures of 350-400°C to yield TI2O3 [94]. 

When heating the samples, the volatility of Tl-compounds has to be taken into consideration. Either oxygen or hydrogen, respectively hydrogen diluted with nitrogen, can be used as carrier gas. The volatility in oxide, chloride or elemental forms leads to evaporation of Tl and some other trace elements selectively from the solid sample, which has to be considered also in technical processing of thallium-containing ores and other materials. 

Their insolubility prevented molecular weight determinations. The thermal stability of the products obtained from a,a -dihydroxysebacic acid, decreased in the order Ni > Co > Cu > Zn > Cd. a,a -Dihydroxysebacic and a,a -dimethoxysebacic acids have been converted to tin-containing (71) and thallium-containing (70) polymers. A variety of dialkyl- and diaryltin compounds was employed for these syntheses. The reduced viscosities that were measured were all very low (0.02-0.04). 

Thallium(III) acetate reacts with alkenes to give 1,2-diol derivatives (see p. 128) while thallium(III) nitrate leads mostly to rearranged carbonyl compounds via organothallium compounds (E.C. Taylor, 1970, 1976 R.J. Ouelette, 1973 W. Rotermund, 1975 R. Criegee, 1979). Very useful reactions in complex syntheses have been those with olefins and ketones (see p. 136) containing conjugated aromatic substituents, e.g. porphyrins (G. W. Kenner, 1973 K.M. Smith, 1975). 

Thallium Compounds - Includes any unique chemical substance that contains thallium as part of that chemical s infrastructure. 

Determination of silver as chloride Discussion. The theory of the process is given under Chloride (Section 11.57). Lead, copper(I), palladium)II), mercury)I), and thallium)I) ions interfere, as do cyanides and thiosulphates. If a mercury(I) [or copper(I) or thallium(I)] salt is present, it must be oxidised with concentrated nitric acid before the precipitation of silver this process also destroys cyanides and thiosulphates. If lead is present, the solution must be diluted so that it contains not more than 0.25 g of the substance in 200 mL, and the hydrochloric acid must be added very slowly. Compounds of bismuth and antimony that hydrolyse in the dilute acid medium used for the complete precipitation of silver must be absent. For possible errors in the weight of silver chloride due to the action of light, see Section 11.57. 

Thiourea forms MX (thiourea) 4 compounds if the lattice energy of MX is iess than 160 Kcal/mole, so that M = K, Rb, or Cs. Other large cations form similar compounds, for example, thallium and lead. The structures consist of columns of cations surrounded by eight sulphur atoms at the comers of an approximately regular cube. Each sulphur atom is shared by two cations. The S—C bonds lie in planes normal to the column, and the NHg groups project into channels which contain the anion, and sometimes water molecules (34). 

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