Reaction with arsenic chloride

The success of the Bart reaction when applied to nuclear- substituted anilines is often much affected by the pH of the reaction-mixture. Furthermore, the yields obtained from some m-substituted anilines, which under the normal conditions are usually low, arc considerably increased by the modifications introduced by Scheller, and by Doak, in which the diazotisation is carried out in ethanolic solution followed by reaction with arsenic trichloride in the presence of a cuprous chloride or bromide catalyst. 

Phosphorus pentoxide gives phosphoryl chloride,10 possibly through an intermediate addition compound.11 In the case of phosphorus trioxide a reducing action was evident, phosphorus trichloride being formed along with the oxychloride.12 The reaction with arsenic trioxide and probably with arsenic pentoxide was found to produce AsC13 and at the same time phosphoryl chloride in the case of the pentoxide.13 The... 

American Method. The process used by the Americans at Edgewood Arsenal for the manufacture of phenarsazine chloride is based on the reaction of diphenylamine with arsenic chloride ... 

Dichloroethylarsine is produced from ethylarsine by reaction with the chlorides of mercury, tin, phosphorus, arsenic, or antimony (58). Dimethyl-arsine reacts with hydrogen iodide or bromide to give the halodimethylarsine (293). 

Berzelius had shown that the quantities of oxygen combined with equal amounts of phosphorus and arsenic in the phosphites and phosphates, and in the arsenites and arsenates, are in the ratio 3 5, and each acid forms three series of salts (i.e., is tribasic). Mitscherlich says for every arsenical salt there is a corresponding phosphorus salt. The so-called neutral salts have the oxygen of the base to that in the acid as 2 5, contain the same amount of water of crystallisation, and precipitate barium chloride leaving a neutral solution. These were formulated by Berzelius as NaO + PO and NaO + AsO (Na=4 X 23, P = 2 x 31, As = 2 x 75) together with combined water they are our Na2HP04 and Na2HAs04, and the reactions with barium chloride are... 

From the reaction with arsenic trichloride it appears that the cyclopenta-dienyl group is more readily displaced from the metal than the 7r-allylic system. In contrast, however, oxidation in the presence of hydrogen chloride of 7r-CsHsMo(CO)2(iT-C3H5) affords the dioxochloro complex tr-CjHs M0O2CI (14). Thus, in this case it is the ir-allyl group which has been displaced from the metal. From these results and comments, therefore, it seems that the stability and reactivity of 7r-allyl complexes varies widely from metal to metal, and also depends on the nature of the other ligands attached to the metal. 

Arsenic trichloride (arsenic(III) chloride), AsQ. is the most common and important haUde of arsenic. It may be formed by spontaneous combination of the elements and, in addition, by the following reactions (/) chlorine with arsenic trioxide (2) sulfur monochloride, 82(11, or a mixture of S2CI2 chlorine, with arsenic trioxide and (J) arsenic trioxide with concentrated hydrochloric acid or with a mixture of sulfuric acid and a chloride. 

Nitrophenylarsonic acid has been prepared by heating p-nitrobenzenediazonium chloride with arsenious acid in hydrochloric acid, by the action of -nitrobenzenediazonium chloride on sodium arsenite, by the action of sodium arsenite on sodium -nitrobenzeneisodiazo oxide, by the diazotization of -nitro-aniline in acetic acid in the presence of arsenic chloride and cuprous chloride, and by the reaction of -nitrobenzenediazonium borofluoride with sodium arsenite in the presence of cuprous chloride. ... 

The Nesmeyanov reaction can also be used for arylarsine syntheses. Usually double salts of diazonium chlorides with zinc chloride are treated with arsenic trichloride and zinc dust in acetone (Hanby and Waters, 1946). Nesmeyanov s school used mainly double salts with ferric chloride and iron powder (Nesmeyanov and Makarova, 1950 Reutov and BundeP, 1955). 

Fig. 8. Arsenic extraction from a reddish brown tropical soil deliberately contaminated with arsenate as a function of reaction time by 0.005M chloride, sulphate, carbonate and phosphate. Redrawn from Goh and Lym (2005).

The first step of the process is performed in a separate, dedicated building. The drums of arsenic trioxide are opened in an air-evacuated chamber and automatically dumped into 50% caustic soda. A dust collection system is used. The drums are carefully washed with water, the washwater is added to the reaction mixture, and the dmms are crushed and sold as scrap metal. The intermediate sodium arsenite is obtained as a 25% solution and is stored in large tanks prior to further reaction. In the next step, the 25% sodium arsenite is treated with methyl chloride to produce the disodium salt DSMA (disodium methanearsenate, hexahydrate). This DSMA can be sold as a herbicide however, it is more generally converted to MSMA, which has more favorable application properties [8]. 

Reaction with chlorine produces arsenic trichloride and sulfur chloride 2AS2S3 + 9CI2 4AsCl3 + 3S2CI2... 

When heated in air at 800°C AS4S4 vapors begin to dissociate to AS2S2 which then ignites to form arsenic oxides. Ignition in chlorine produces arsenic chloride. Reaction with fluorine forms arsenic trifluoride. It is stable in water and also in the air at ambient temperatures. It does not react with hot concentrated HCl but is decomposed by nitric acid. It forms thioarsenite ion, AsS3 and elemental arsenic when warmed with caustic soda solution. Similar reaction occurs with sodium sulfide. 

According to C. F. Barwald and A. Monheim (1835), the decomposition is accelerated by the presence of organic substances. J. Milbauer tried the effect of thirty-two metal chlorides of sodium tungstate and molybdate of uranyl sulphate and of sulphuric, selenic, arsenic, and boric acids on the photo-decomposition of chlorine water, and found. that none accelerated but that most retarded the action. Chlorine catalyzes the decomposition of bromine water and bromine, chlorine water while iodine does not accelerate, but rather retards the reaction, probably by forming relatively stable iodine compounds. A. Bcnrath and H. Tuchel found the temp, coeff. of the velocity of the reaction with chlorine water between 5° and 30° increases in the ratio 1 1 395 per 10°. 

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