Cacodylic compounds

Seyferth, D. (2001) Cadet s fuming arsenical liquid and the cacodyl compounds of Bunsen. Organometallics, 20, 1488-98. 

D. Seyferth, Cadet s Fuming Arsenical Liquid and the Cacodyl Compounds of Bunsen,... 

Cacodyl oxide reaction If a dry acetate, preferably that of sodium or potassium, is heated in an ignition tube or test-tube with a small quantity of arsenic(III) oxide, an extremely nauseating odour of cacodyl oxide is produced. All cacodyl compounds are extremely POISONOUS the experiment must therefore be performed on a very small scale, and preferably in the fume chamber. Mix not more than 0-2 g sodium acetate with 0-2 g arsenic(III) oxide in an ignition tube and warm observe the extremely unpleasant odour that is produced. 

These derivatives, the tetra-alkyldiarsincs, which go under the name of cacodyl compounds, were amongst the earliest arscnicals to be investigated, and they date back to 1837. The only representatives of this group which are known Avith certainty are tlic methyl and ethyl derivatives. They may be isolated ... 

These arsenic compounds are known as cacodyl compounds. The... 

The extensive series of dimethylarsenic compounds, often called cacodyl compounds, e.g., Me2AsCl, cacodyl chloride, is worthy of mention. There are also diarsenic tetraalkyls such as dicacodyl, Me2AsAsMe2, and Et2AsAsEt2. 

The cacodyl radical [(CH3)2As] also appeared to Bunsen to be a stable superatom that could be exchanged amongst other radicals. Many cacodyl compounds are explosive as well as spontaneously flammable. One of these, cacodyl cyanide [(CH3)2AsCN], exploded during Bunsen s exploratory studies, and he lost his right eye. ... 

Some books [1-4] on organometallic chemistry described Zeise s salt [5] reported in 1827 or a cacodyl compound (tetramethyldiarsine) synthesized by Bunsen ten years later [6] as the first organometallic compound. However, the synthetic reaction of cacodyl compounds was reported in 1760 by Cadet at least 80 years before Bunsen s report [7,8]. Cadet obtained the cacodyl as liable substance which shows the characteristics of organometallic compound. However, in general, it is not considered as the first compound of the organometallic compound group since, it was not isolated as a single substance and its composition was not revealed. 

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