Thallium complexes nitrates

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). 

The potassium derivatives obtained from the reaction mixture are typically not isolated in pure form, and the crude products are often converted directly to the thallium complexes by metathesis with either thallium nitrate or thallium acetate [Eqs. (1) and (2)]. 

Oxidative rearrangements, via oxythallation, have been improved in yield and selectivity by the use of thallium(iii) nitrate supported on clay rather than in methanolic solution. Thus, cyclohexene gave an 85% yield of dimethoxymethyl-cyclopentane while 1-tetralone, which normally gives a complex mixture of products, gave a 1 1 mixture of methyl indane-l-carboxylate and 2-methoxytetralone. An efficient, large-scale procedure for the direct cis-dihydroxylation of olefins has been reported. The oxidant is t-butyl hydroperoxide and the catalyst osmium tetroxide, with the reaction conducted under alkaline conditions (E%N OH ), so facilitating a rapid turnover of catalyst via enhanced hydrolysis of the osmate esters. The method appears to be more advantageous for the more substituted olefins than the Hofmann and Miles procedure. 

The influence of electronic effects on the binding mode of tetraalkynylplatinate anions is apparent in the reactions of compounds of general formula Li2[Pt (C=CR)4] with thallium(l) nitrate [72]. For electrrai-rich alkynyl moieties (R = p-tolyl, 1-naphtyl), discrete hexanuclear structures are obtained (Scheme 16, top), in which each Tl center interacts with four C=C triple bonds and not with the platinum atom. The introduction of a remote electron-withdrawing substituent oti the alkynyl unit (R = p-CFsC lU) induces a dramatic change in the structure of the Lewis acid-base complex each platinum atom now involves in donor-acceptor bonds with two thaUium(I) ions (Pt-Tl 2.9355(5) and 3.0272(5) A), one oti each face of its coordination plane. These Tl2Pt units are interconnected by weak interactions of thallium with the Jt-elecfron density of the triple bonds. 

Reactions.—Cleavage of prenyl and allyl ethers has been discussed earlier in this Report. Some aliphatic ethers can be cleaved by thallium(iii) nitrate in acetic anhydride.New reagents for the demethylation of aryl methyl ethers include the stable, crystalline, and easily handled complexes of boron halides BBr3 and BCI3 with dimethyl sulphide,and the salt obtained from treatment of N-methylaniline with sodium hydride in HMPA. The latter system cleaves methyl aryl ethers more readily than benzyl aryl ethers. 

Tri-n-butyl phosphate, ( -C4H9)3P04. This solvent is useful for the extraction of metal thiocyanate complexes, of nitrates from nitric acid solution (e.g. cerium, thallium, and uranium), of chloride complexes, and of acetic acid from aqueous solution. In the analysis of steel, iron(III) may be removed as the soluble iron(III) thiocyanate . The solvent is non-volatile, non-flammable, and rapid in its action. 

Our first study of these systems was the synthesis in 1998 of the polymeric complex [ 1( 6 5)2( )2] through the reaction between triphenylphosphine oxide, thallium nitrate and lithium bis(pentafluorophenyl)aurate(I) [71]. This complex consisted of an extended unsupported linear chain of alternate gold and thallium centers. These atoms displayed Au-Tl interactions of 3.0358(8) and 3.0862(8) A, and the thallium atoms showed a distorted pseudo-trigonal-bipyramidal environment, taking into account the stereochemically active inert pair of this atom. As described below, the environment around thallium is one of the main factors that affects the optical properties of these mixed systems. 

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... 

G. Canneri found that the treatment of a suspension of thallium sesquioxide in water with liquid nitrous anhydride, and subsequent evaporation of the soln., even in the cold under reduced press., yields, not thallic nitrite, but thallous nitrate. The latter is also obtained when soln. of thallic sulphate and barium nitrite are mixed in the cold, and the resulting liquid evaporated at low temp. That thallic nitrite is capable of existence in soln., although it cannot be obtained in the solid condition, is shown by the analyses and properties of the soln. The treatment of an aq. soln. of thallic nitrite with alcohol yields a precipitate of the sequioxide. In ethereal soln., thallic nitrite is far more stable, and the salt separates in the solid state on evaporation of the solvent it could not, however, be analyzed directly. Decomposition of thallic nitrite, with formation of thallous nitrate, takes place solely in accordance with the equation T1 (N02)3->TlN03+N2Os, neither intermediate reduction products nor thallous-thallic complex compounds being formed. 

Sutton (666) and Kul ba (458-460) have prepared a number of bipyridyl and phenanthroline complexes of various thallium(III) salts those with nitrate and perchlorate are generally bis-chelate compounds, whereas the halides give compounds of stoichiometry TIX3L. Stability constants have been reported for some of the complexes (457). Other mixed ligand species containing ethylenediamine (461) and oxalate (456) and salts containing both bipyridyl and phenanthroline coordinated to the same thallium(III) ion (456) are also claimed. 

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