Arsenious oxide, phenyl diphenyl

Mercury diphenyl has been prepared in a number of ways. The most important methods are by the action of sodium on a mixture of bromobcnzene and mercuric chloride 1 from sodium amalgam and phenyl mercuric iodide 2 by the interaction of phenyl mercuric bromide and potassium sulfide2 or phenyl mercuric acetate and sodium stannite 3 from phenyl magnesium bromide and mercuric chloride 4 by the action of phenyl hydrazine on mercury compounds 5 from mercuric chloride and phenyl arsenious oxide 6 and from diphenyl mercuric ammonium acetate and sulfur compounds.7... 

The mixture is stirred continuously and maintained for 3 hours at 15° C., when sodium phenyl arsenate is formed. This is neutralised with hydrochloric acid and filtered through a press in order to separate resinous substances which are formed. The phenyl arsenic acid in the filtrate is reduced to phenyl arsenious oxide by passing a current of sulphur dioxide through. A heavy oil deposits at the bottom of the vessel and this is removed by decantation and redissolved in 40° B. sodium hydroxide solution. After diluting with 8 cu. m. of water, the solution is cooled to 15° C. and run slowly into another solution of diazobenzene chloride prepared as before. The sodium salt of diphenyl arsenic acid which is formed is slightly acidified with hydrochloric acid, the diphenyl arsenic acid filtered off and redissolved in 20° B6. hydrochloric acid (i part of the arsenic acid requires 3 parts of hydrochloric acid) and the solution obtained is then run into an iron vessel, lined internally with tiles. Sulphur dioxide is then passed through for 8 hours while the temperature is maintained at about 80° C. Diphenyl chloroarsine then separates as an oil which forms a layer at the bottom of the vessel. It is separated off and dried in vacuo. 

The body shows decomposition if heated above 270° C. and burns in air with a reddish flame and the separation of lead oxide. It is moderately soluble in chloroform, benzene, or carbon bisulphide when hot, and difficultly soluble in alcohol, ether, ligroin, or acetic acid. If heated in a sealed tube with hydrochloric acid decomposition occurs, lead tetrachloride and benzene being produced. By the action of halogens or concentrated nitric acid two phenyl groups are split off, and a lead diphenyl dihalide or dinitrate formed. A similar action takes place with iodic acid, formic, acetic, trichloracetic, propionic, valeric, and p-nitrobenzoic acids. With metallic chlorides the following derivatives are formed arsenic trichloride — lead diphenyl dichloride and diphenyl arsenious chloride antimony trichloride — lead diphenyl dichloride and diphenylstibine chloride antimony penta-chloride — lead diphenyl dichloride and diphenylstibine trichloride bismuth tribromide —> lead diphenyl dichloride and diphenylchloro-bismuthine thallie chloride —> lead diphenyl dichloride and thallium diphenyl chloride tellurium tetrachloride —> lead diphenyl dichloride and tellurium diphenyl dichloride. 

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