1603. Cacodyl

Nomenclature

CAS number: 471-35-2
1,1,2,2-Tetramethyldiarsine; tetramethyldiarsenic; dicacodyl.
C4H12As2; mol wt 209.98.
C 22.88%, H 5.76%, As 71.36%.

Description and references

Prepn from cacodyl chloride by heating with zinc in an atm of carbon dioxide: Bunsen, Ann. 42, 14 (1842); from dimethylarsine by the action of oxides of nitrogen, aqueous chromic acid, lead peroxide, cacodyl chloride or potassium ferricyanide: Dehn, Wilcox, Am. Chem. J. 35, 1 (1906); by the action of free methyl on arsenic: Paneth, Loleit, J. Chem. Soc. 1935, 366; by reduction of cacodyl oxide: Witten, US 2531487 (1950 to U.S.A.); Fuson, Shive, US 2756245 (1956 to U.S.A.).

Chemical structure

Properties

Oily liquid. Solidifies to large quadratic plates, mp -6°. Almost intolerable garlicky odor. Inflames spontaneously in dry air. bp760 165°. Slightly sol in water. Controlled oxidation with moist air yields cacodyl oxide and cacodylic acid. Reduction with tin and HCl yields Erytrarsin (CH3As)4As2O3.