Thallium perchlorate solutions

Calculate from the standard potentials of cadmium and thallium the ratio of the activities of Cd " and Tl ions when metallic cadmium is shaken with thallous perchlorate solution until equilibrium is attained. 

The compound is obtained very easily by admixing a soluble azide to an aqueous thallium(I) salt solution. The product precipitates immediately as a straw-yellow crystal powder. Larger crystals are obtainable by cooling hot, saturated aqueous solutions [62]. Combinations such as thallium sulfate/ potassium azide [237] and thallium nitrate/ammonium azide [61] may be used for the preparation. This author prefers thallium perchlorate and sodium azide, because favorable solubility products of the ions involved and the absence of hydration lead to a material that is free of coprecipitated ions. For example, to a stirred solution of 200 g TICIO4 in 1600 ml water is admixed 45 g sodium azide dissolved in 150 ml water. The dense precipitate is washed with cold water until perchlorate free, and then with acetone. Practical yield, 152 g. The product should be stored completely dry as the damp material tends to discolor [236]. 

Thallium perchlorate is readily soluble in water the solution is a good conductor and does not change on exposure to air. Lower current densities (about 0.5 amp./lOO cm. ) provide good deposits on addition of only 10 g. of excess HClO /liter. The peptone gives a yellow precipitate, but does not interfere in any way. Higher current densities (0.9-1.8 amp./lOO cm. ) also yield good deposits when concentrated solutions with up to 60 g. of free HCIO4 /liter are used. 

The existence of dimeric and polymeric species in aqueous solutions of indium(m) and thallium(iii) has an effect on kinetics of systems which include these reactants. A T-jump study of indium(iii) perchlorate solution has yielded a value for the rate constant for dimerisation of [InOH] +. Due to ion-pairing complications, it has not proved possible to determine unequivocally, by comparison of rate constants of this and of the indium(m)-sulphate system, whether the rate-determining step in dimerisation of [InOH] + is loss of a solvating water molecule from the indium. The situation is entirely similar for gallium(iii) in perchlorate solution. ... 

Upon addition of perchlorate ions to the acetonitrile solutions, the salt [(MeCN)2ln Mn(C0)j 2]C104 can be isolated. This will react with pyridine or phenanthroline to yield [L2ln Mn(C0)5 2]C104 (L = py or phen). The compounds R4N[X4 In Mn(CO)5)J (n = 1—3 R = Me, X = Cl R == Et, X = Br) have also been prepared. Thus this work shows that as well as influencing the amount of dissociation of metal-metal bonded complexes, the nature of the solvent also determines the mode of ionization. The complex [TljMnlCOljlj] can be conveniently prepared from thallium(i) salts and [Na(Mn(CO)g ]. ... 

Waszczuk et al. [329] have carried out radiometric studies of UPD of thallium on single-crystal Ag electrode from perchloric acid solutions. Deposition of Tl on Ag(lOO) to obtain monolayer, bilayer, and bulk crystallites has been studied by Wang et al. [330]. These studies have shown that apart from the substrate geometry, the nature of the substrate-adatom interactions also influence the structure of the UPD metal adlayers. This is because of the fact that, contrary to Au and Pt electrodes, Tl forms a well-ordered bilayer phase before bulk deposition on Ag(lOO) surface occurs. 

Thallium(I) halides are predominantly ionic, although there is a tendency toward increasing covalent character in the series of compounds TlCl (17%), TlBr (20%), and TII (28%). This increased degree of covalency results in decreased solubility for example, TIF is soluble in water whilst the other Tl halides are only sparingly soluble. The thallium(I) halides are classical examples of incompletely dissociated 1 1 electrolytes. The stability of halide complexes of Tl is low and follows the order TIF < TlCl < TlBr < TII, where for the series of halides, Kx = -, 0.8, 2.1, 5.0 and Ki = -, 0.2, 0.7, 1.5 respectively. The fluoride ion F is preferred to perchlorate as a noncomplexing counterion. Claims have been made for T1X species with n = 3 and 4 however, the formation of complexes in aqueous solution with n > 2 seems unlikely. 

Diarylacetylenes are converted in 55-90% yields into a-diketones by refluxing for 2-7 h with thallium trinitrate in glyme solutions containing perchloric acid [413. Other oxidants capable of achieving the same oxidation are ozone [84], selenium dioxide [509], zinc dichromate [660], molybdenum peroxo complex with HMPA [534], potassium permanganate in buffered solutions [848, 856, 864,1117], zinc permanganate [898], osmium tetroxide with potassium chlorate [717], ruthenium tetroxide and sodium hypochlorite or periodate [938], dimethyl sulfoxide and iV-bromosuccin-imide [997], and iodosobenzene in the presence of a ruthenium catalyst [787] (equation 143). 

A solution of 1.78 g (0.01 mol) of dipbenylacetylene in 20 mL of glyme is added to a solution of 8.9 g (0.02 mol) of thallium trinitrate in 10 mL of water containing 5 mL of 70% perchloric acid. The mixture is gently refluxed for 3 h. After the mixture has been cooled, thallium mononitrate is filtered off, and the filtrate is diluted with 100 mL of water. The mixture is extracted with two 25-mL portions of chloroform. The chloroform extract is dried with anhydrous sodium... 

A number of elements form volatile chlorides that are partially or completely lost from hot hydrochloric acid solutions. Among these are the chlorides of tin(IV), germanium(IV), antimony(III), arsenic(III), and mercury(II). The oxychlorides of selenium and tellurium also volatilize to some extent from hot hydrochloric acid. The presence of chloride ion in hot concentrated sulfuric or perchloric acid solutions can cau.se volatilization losses of bismuth, manganese, molybdenum, thallium, vanadium, and chromium. 

The most substantial investigation of thallium(II) species in aqueous solution is that of Dodson and Schwarz, who studied equilibria and kinetics of Tl(II)-Cr complexes (77). On the basis of some (reasonable) assumptions, they have calculated the stepwise stability constants K for the three T1C1 " complexes, n = 1,2,3, in 1M HCIO4 and estimated = 1 from the ratios between the stability constants K, for Tfi Cl " and TT C1 ". The absorption spectra of the individual Tl(II) chloride complexes have been derived from their stability constants in combination with the experimental spectra recorded for solutions with varying composition. Absorption maxima were found at 263 and 342 nm for TlCl, at 280 and 342 nm for TICI2, and at 304 and 362 nm for TlCla". An interesting observation was the 10-fold increase of the extinction coefficient (at —340 nm) of the Tl(II) solution in 1 M perchloric acid upon addition of a small amount of chloride ion ([Cl ] = 10 M) (77). 

The two isotopes, 203T1 and 205T1 (70.48%), both have nuclear spin, and nmr signals are readily detected for thallium solutions or for solids. In solution both Tl1 and Tl111 resonances are markedly dependent on concentration and on the nature of anions present such data have shown that thallous perchlorate is highly dissociated, but salts of weaker acids and TIOH have been shown to form ion pairs in solution. 

Ionic reactions between solvo-acids and solvo-bases may lead to insoluble products such as thallium sulphate formed from mercury(II) sulphate and thallium bromide in molten mercury(II) bromide. Similarly anhydrous copper(II) sulphate can be prepared by using a copper(II) halide. Perchlorates, nitrates and phosphates of many other elements can be prepared in a similar manner. By allowing mer-cury(II) oxide to react with the sulphate in mercury(II) bromide solution a red, insoluble product of composition (Hg0)2HgS04 is formed. Analogous compounds are formed from the sulphide, selenide and telluride of mercury in molten mercuric bromide. 

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