Thallium -perchlorate

Similarly, TTN-mediated oxidation of 4-aUcylphenols in MeOH provided 4-alkyl-4-methoxycyclohexa-2,5-dienones (see Scheme 74). Thallium perchlorate [11(0104)3] was also apphed to the oxidation of phenols 816 and 817 leading to cyclohexadienones 818 and 819, respectively, each in 80% yield (Scheme 163) . However, when 4-alkylphenols such as 27 and 820 were treated with T1(C104)3-60% HCIO4 in CH2CI2 they gave 2-alkyl-p-benzoquinones 290 and 821 in 70 and 66% yields, respectively (Scheme 163). ... 

SCHEME 163. Oxidation of 4-alkylphenols with thallium perchlorate... 

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]. 

It is advisable to protect T1 from surface oxidation by coating it with a layer of paraffin or storing it under glycerol or petroleum. II. Brown and McGlynn report preparation of a good, smooth, cohesive electrolytic deposit of metallic T1 from a thallium perchlorate bath containing peptone as an anodic depolarizer and cresol as a further additive. Current densities of 0.5 to 1.8 amp./ 100 cm. are used. 

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. 

Thallium(1) salts of tetrahydridoborate and aluminate are obtained from a T1(I) compound, eg, ethoxide, perchlorate, or nitrate, and LiBH or LiAlH ia ether. ThaIlium(I) tetrahydridoborate [61204-71 -5] TIBH, is unstable at 40°C, evolving diborane. Thallium(I) tetrahydridoaluminate... 

Z 1 Niobium 1 Nitrate 1 Osmium 73 a. I Perchlorate Phenols u a o Platinum o 0. 1 5 u 1 Rhodium 1 Rubidium Ruthenium Scandium 1 Selenium Silver I Sodium 1 Strontium 1 Sulphate Sulphides, organic Sulphur dioxide 1 Tantalum 1 Tellurium 1 Thallium Thorium e H 1 Titanium a u ab a 1- I Uranium 1 Vanadium 1 Yttrium 1 Zinc Zirconium... 

Thallium Salts. Although the same prepn had been carried out many times a violent expln occurred during the evapn of a soln. of ethylbenzene, T1 triacetate, and perchloric ac in acetic ac. No satisfactory explanation for the expln was found (Ref 40)... 

While the above examples demonstrate that product control to a significant extent is possible in oxythallation by careful choice of substrate or reaction conditions, the synthetic utility of oxythallation has been illustrated most convincingly by the results obtained with highly ionic thallium(III) salts, especially the nitrate (hereafter abbreviated TTN). Unlike the sulfate, perchlorate, or fluoroborate salts (165), TTN can easily be obtained as the stable, crystalline trihydrate which is soluble in alcohols, carboxylic acids, ethers such as dimethoxyethane (glyme), and dilute mineral acids. Oxidations by TTN can therefore be carried out under a wide variety of experimental conditions. 

Littler has studied the oxidation of cyclohexanone with lead(IV), thallium(III), and mercury(II) salts (84), and found that, with all three reagents the rates of oxidation are independent of the concentration of oxidant. Oxidation by thallium(III) and mercury(II) in 35% aqueous perchloric acid showed first-order dependence on [H" ], and Littler suggested that the results were best interpreted in terms of the reaction sequence shown in Scheme 27. The major product of thallium(III) oxidation of... 

Wiberg and Koch 167) also disagreed with Littler s results, and found that the major product (75%) obtained on treatment of cyclohexanone with aqueous thallium(III) perchlorate was cyclopentanecarboxylic acid (XL). 2-Hydroxycyclohexanone was isolated in only 3 % yield unchanged starting material accounted for the remainder of the product. Wiberg and Koch were unable to detect any cyclohexane-1,2-dione in the product mixture, but did prove that 2-hydroxycyclohexanone did not function as the precursor to the ring-contracted acid. From the results obtained from a study of the oxidation of 2,2,6,6-[Pg.196]

Ethylbenzene, Thallium triacetate Ucmura, S. et al., Bull. Chem. Soc., Japan., 1971, 44, 2571 Application of a published method of thallation to ethylbenzene caused a violent explosion. A reaction mixture of thallium triacetate, acetic acid, perchloric acid and ethylbenzene was stirred at 65°C for 5 h, then filtered from thallous salts. Vacuum evaporation of the filtrate at 60°C gave a pasty residue which exploded. This preparation of ethylphenylthallic acetate perchlorate monohydrate had been done twice previously and uneventfully, as had been analogous preparations involving thallation of benzene, toluene, three isomeric xylenes and anisole in a total of 150 runs, where excessive evaporation had been avoided. 

Sodium perborate monohydrate Sodium perborate tetrahydrate Sodium percarbonate Sodium perchlorate Sodium perchlorate monohydrate Sodium permanganate Sodium peroxide Sodium persulfate Strontium chlorate Strontium perchlorate Strontium peroxide Tetranitromethane Thallium chlorate Trichloro-s-triazinetrione (trichloroisocyanuric) (acid all forms)... 

Association constants for salts of copper, silver, and thallium appear to reflect solvation in a fairly simple way. For example, of the perchlorate salts, only those of the poorly solvated thallium ion show association. 

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. 

A cationic mechanism is responsible for the ring contraction of cycloalkenes with thallium(III) salts in the presence of diluted perchloric acid resulting in the formation of formylcycloalkanes. This method was unsuccessful for cyclopentene, whereas 1-methylcyclopentene gave acetyicy-clobutane (32) in 16-24% yield98 depending on the better stabilization of the intermediate cationic species. 

Thallium (III) perchlorate is obtained from T1CI3 + AgC104, or by the anodic oxidation of T1C104. Complexing by perchlorate appears very unlikely and the same applies to chlorate, bromate or iodate.1-3... 

Cationic complexes of Tl3+ with oxygen donors are known, and can be regarded as substitution products of [T1(C)H2)6]3+ (c/. Section 25.2.8.3.1). The DMSO product has been characterized with various anions,403 and there seems no reason to suppose that similar compounds cannot be prepared with donor ligands which are resistant to oxidation. The cation [Tl(pyNO)8]3+ (prepared as the perchlorate) may be an indication that eight-coordinate compounds are also accessible in thallium(III) chemistry.404... 

Adducts of triazoles with transition metal salts are usually prepared by direct reactions between the two components involved and frequently precipitate or crystallize spontaneously from the reaction mixture (55,172,194, 202). Complexes containing triazolate anions can usually be obtained from the corresponding transition metal halide, carboxylate, nitrate, or perchlorate complex and an alkali metal (146, 147, 172) or thallium(I) triazolate salt (33). Other routes to triazolate complexes include the direct reactions of metal halides with triazoles in the presence of a base (201) and the treatment of triazole/metal halide... 

Intramolecular electron transfer in a stepwise manner from the amine substrate to die silver(III) center in a 1 2 complex, [Ag(OH)4] -iV,/V-dimcthylanilinc, has been observed.44 The kinetics of oxidation of some aliphatic, heterocyclic, and aromatic aldehydes towards bis(dihydrogentellurato)cuprate(III) and argentate(III) in alkaline medium have been studied.45 A negative salt effect was observed in the oxidation of aminoacetic acid by diperiodatocuprate(III) complex in alkaline medium.46 The oxidation of glutamic acid by thallium(III) perchlorate is catalysed by Ru(M), Os(III), and Nd(III) in a free radical mechanism and the rate is inversely dependent on [H+] concentration.47... 

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