Carbon disulfide

Carbon disulfide (also spelled as carbon disulphide) is an inorganic compound with the chemical formula and structure . It is a colorless, flammable, neurotoxic liquid that is used as a building block in organic synthesis. Pure carbon disulfide has a pleasant, ether- or chloroform-like odor, but commercial samples are usually yellowish and are typically contaminated with foul-smelling impurities. In 1796, the German chemist Wilhelm August Lampadius (1772–1842) first prepared carbon disulfide by heating pyrite with moist charcoal. He called it "liquid sulfur" (flüssig Schwefel). The composition of carbon disulfide was finally determined in 1813 by the team of the Swedish chemist Jöns Jacob Berzelius (1779–1848) and the Swiss-British chemist Alexander Marcet (1770–1822). Their analysis was consistent with an empirical formula of CS2. Small amounts of carbon disulfide are released by volcanic eruptions and marshes. CS2 once was manufactured by combining carbon (or coke) and sulfur at 800–1000 °C. C + 2S → CS2 A lower-temperature reaction, requiring only 600 °C, utilizes natural gas as the carbon source in the presence of silica gel or alumina catalysts: 2 CH4 + S8 → 2 CS2 + 4 H2S The reaction is analogous to the combustion of methane. Global production/consumption of carbon disulfide is approximately one million tonnes, with China consuming 49%, followed by India at 13%, mostly for the production of rayon fiber. United States production in 2007 was 56,000 tonnes. Carbon disulfide is a solvent for phosphorus, sulfur, selenium, bromine, iodine, fats, resins, rubber, and asphalt. Combustion of CS2 affords sulfur dioxide according to this ideal stoichiometry: CS2 + 3 O2 → CO2 + 2 SO2 For example, amines afford dithiocarbamates: 2 R2NH + CS2 → [R2NH2+][R2NCS2−] Xanthates form similarly from alkoxides: RONa + CS2 → [Na+][ROCS2−] This reaction is the basis of the manufacture of regenerated cellulose, the main ingredient of viscose, rayon, and cellophane.