Arsenic halides reactions

By direct action of chlorine on arsenic. When powdered arsenic is sprinkled into chlorine gas,1 or into liquid chlorine near its boiling point,2 union occurs with incandescence and a white cloud of the trichloride is formed. If the gas is passed over arsenic in a tube connected with a receiver immersed in a freezing mixture, the powder which condenses is yellow, owing to excess of chlorine the latter may be removed by distillation from powdered arsenic. The reaction is accelerated by the addition of a trace of bromine or of alkali halide.3 When chlorine is passed into a solution of yellow arsenic in carbon disulphide, brown arsenic is first precipitated, which is then converted to arsenic trichloride.4... 

The methyl arsenic system compromises two well-defined species, the pentamer (MeAs)5, a yellow pyrophoric oil (m.p. 12°C) and the purple black double-chain polymer, [(MeAs)2] (m.p. 204 °C). A red solid that is possibly the linear chain compound (MeAs) has also been described. The polymers are formed when samples of the pentamer are exposed to impurities like arsenic halides that are able to react with the arsenic-arsenic bond and may act as end groups. The most widely used method for the preparation of larger amounts of (MeAs)j is the reduction of methylarsonic acid, MeAsO(OH)2, or its sodium salt with hypophosphoric acid " °. Samples prepared by this method, however, may contain between 5 and 15% of impurities. A method that minimizes impurities is the reaction of MeAsHj with dibenzylmercury (equation 3) °. 

Reaction of organoantimony anionic species with phosphorus and arsenic halides... 

Reactions of Grignard reagents or organolithium compounds with arsenic halides, usually chlorides, have been one of the most frequently used method for the preparation of triorganoarsenic compounds. A wide variety of triorganoarsenic(III) compounds have been prepared as shown in equations 1 , 2 , 3 , 4 , 5 , 6 , 7 and 8 . 

Friedel-Crafts reaction of arsenic halides has been reported to give aromatic compounds as shown in equation 40 . Reactions with alkynes usually give mixtures of... 

Primary and secondary arsines have also been used for reactions with arsenic halides (equations 193 ° and 194 ). 

Arsonic acids have been prepared from readily available compounds such as arsenic(III) oxide and arsenic trichloride. Reaction of sodium arsenite with alkyl halides has been named the Meyer reaction, and reaction with arenediazonium salts the Bart reaction. In addition, some modifications have been made for the preparation of arsonic acids. Some examples are shown in equations 326 and 327. ... 

Reaction of arsenic halides with alkynes or aromatic compounds... 

---