Carbon disulfide

Carbon disulfide, also spelled as carbon disulphide, is a colorless volatile liquid with the formula CS2. The compound is used frequently as a building block in organic chemistry as well as an industrial and chemical non-polar solvent. It has an "ether-like" odor, but commercial samples are typically contaminated with foul-smelling impurities.
Occurrence, manufacture, properties.
Small amounts of carbon disulfide are released by volcanic eruptions and marshes. CS2 once was manufactured by combining carbon (or coke) and sulfur at high temperatures.
A lower-temperature reaction, requiring only 600 °C, utilizes natural gas as the carbon source in the presence of silica gel or alumina catalysts:
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.
Solvent.
Carbon disulfide is a solvent for phosphorus, sulfur, selenium, bromine, iodine, fats, resins, rubber, and asphalt. It has been used in the purification of single-walled carbon nanotubes.
Reactions.
CS2 is highly flammable. Its combustion affords sulfur dioxide according to this ideal stoichiometry:
With nucleophiles.
Compared to the isoelectronic carbon dioxide, CS2 is a weaker electrophile. While, however, reactions of nucleophiles with CO2 are highly reversible and products are only isolated with very strong nucleophiles, the reactions with CS2 are thermodynamically more favored allowing the formation of products with less reactive nucleophiles. For example, amines afford dithiocarbamates:
Xanthates form similarly from alkoxides:
This reaction is the basis of the manufacture of regenerated cellulose, the main ingredient of viscose, rayon and cellophane. Both xanthates and the related thioxanthates (derived from treatment of CS2 with sodium thiolates) are used as flotation agents in mineral processing.
Sodium sulfide affords trithiocarbonate:
Carbon disulfide does not hydrolyze readily, although the process is catalyzed by an enzyme carbon disulfide hydrolase.
Reduction.
Reduction of carbon disulfide with sodium affords sodium 1,3-dithiole-2-thione-4,5-dithiolate together with sodium trithiocarbonate:
Chlorination.
Chlorination of CS2 provides a route to carbon tetrachloride:
This conversion proceeds via the intermediacy of thiophosgene, CSCl2.
Coordination chemistry.
CS2 is a ligand for many metal complexes, forming pi complexes. One example is CpCo(η2-CS2)(PMe3).
Polymerization.
CS2 polymerizes upon photolysis or under high pressure to give an insoluble material called car-sul or "Bridgman's black", named after the discoverer of the polymer, Percy Williams Bridgman. Trithiocarbonate (-S-C(S)-S-) linkages comprise, in part, the backbone of the polymer, which is a semiconductor.
Uses.
The principal industrial uses of carbon disulfide, consuming 75% of the annual production, are the manufacture of viscose rayon and cellophane film.
It is also a valued intermediate in chemical synthesis of carbon tetrachloride. It is widely used in the synthesis of organosulfur compounds such as metam sodium, xanthates, dithiocarbamates, which are used in extractive metallurgy and rubber chemistry.
Niche uses.
It can be used in fumigation of airtight storage warehouses, airtight flat storages, bins, grain elevators, railroad box cars, shipholds, barges and cereal mills. Carbon disulfide is also used as an insecticide for the fumigation of grains, nursery stock, in fresh fruit conservation and as a soil disinfectant against insects and nematodes.
Health effects.
Carbon disulfide has been linked to both acute and chronic forms of poisoning, with a diverse range of symptoms. Typical recommended TLV is 30 mg/m3, 10 ppm. Possible symptoms include, but are not limited to, tingling or numbness, loss of appetite, blurred vision, cramps, muscle weakness, pain, neurophysiological impairment, priapism, erectile dysfunction, psychosis, keratitis, and death by respiratory failure. 
Occupational exposure to carbon disulfide is associated with cardiovascular disease, particularly stroke.
History.
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.