Thallium organic compounds preparation

Monoalkylthallium(III) compounds can be prepared easily and rapidly by treatment of olefins with thallium(III) salts, i.e., oxythallation (66). In marked contrast to the analogous oxymercuration reaction (66), however, where treatment of olefins with mercury(II) salts results in formation of stable organomercurials, the monoalkylthallium(III) derivatives obtained from oxythallation are in the vast majority of cases spontaneously unstable, and cannot be isolated under the reaction conditions employed. Oxythallation adducts have been isolated on a number of occasions (61, 71,104,128), but the predominant reaction pathway which has been observed in oxythallation reactions is initial formation of an alkylthallium(III) derivative and subsequent rapid decomposition of this intermediate to give products derived by oxidation of the organic substrate and simultaneous reduction of the thallium from thallium(III) to thallium(I). The ease and rapidity with which these reactions occur have stimulated interest not only in the preparation and properties of monoalkylthallium(III) derivatives, but in the mechanism and stereochemistry of oxythallation, and in the development of specific synthetic organic transformations based on oxidation of unsaturated systems by thallium(III) salts. 

Claude-Auguste Lamy, 1820—1878. President of the SociSte Chimique de France in 1873 The first person to prepare an ingot of metallic thallium. He made a thorough study of its compounds and proved that they are poisonous Author of many papers on optics, electricity, pyrometry, organic and inorganic chemistry, and sugar technology. 

Tlie first organic thallium compound was obtained by Hansen, by treating zinc diethyl with thallic chloride. Four years later Hartwig -prepared salts of the type R/flX. No further work was done upon the metal until 1904, when Meyer and Bertheim isolated thallium dimethyl chloride by a reaction which may be expressed in a general form ... 

Thallium di-o-tolyl chloride,— This compound is prepared by the action of thallie chloride on magnesium o-tolyl bromide, then boiling the product obtained with dilute hydrochloric acid. It crystallises from pyridine in slender, microscopic needles, which do not melt at 300° C. and are insoluble in all organic solvents. 

To prepare a film one allows a solution of the sample to evaporate slowly on the face of a suitable window material. The plate may be gradually heated if necessary. For many compounds this means dissolution in a volatile organic solvent, and an alkali halide plate is used. Films of such substances as proteins and mucopolysaccharides have frequently been cast from aqueous solution on a silver chloride plate. IRTRAN-2 (ZnS) and KRS-5 (thallium bromoiodide) plates can also be used. 

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