Carbon disulfide 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, such as carbonyl sulfide.1
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:1
- 2CH4 + S8 → 2CS2 + 4H2S
- CS2 + 3O2 → CO2 + 2SO2
Compared to CO2, CS2 is more reactive toward nucleophiles and more easily reduced. These differences in reactivity can be attributed to the weaker π donor-ability of the sulfido centers, which renders the carbon more electrophilic. It is widely used in the synthesis of organosulfur compounds such as metham sodium, a soil fumigant and is commonly used in the production of the soft fabric viscose.
Nucleophiles such as amines afford dithiocarbamates:
- 2R2NH + CS2 → [R2NH2+[R2NCS2−
- RONa + CS2 → [Na+[ROCS2−
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:
- Na2S + CS2 → [Na+2[CS32−
This conversion proceeds via the intermediacy of thiophosgene, CSCl2.
Carbon disulfide is naturally formed in the mudpots of volcanic solfataras. It serves as a source of hydrogen sulfide, which is an electron donor for certain organisms that oxidize it into sulphuric acid or related sulfur oxides. The hyperthermophilic Acidianus strain was found to convert CS2 into H2S and CO2. The enzyme responsible for this conversion is termed carbon disulfide hydrolase.3
The mechanism by this hydrolase converts CS2 into H2S is similar to that of how carbonic anhydrase hydrates CO2 to HCO3-. This similarity points to a likely mechanism.
CS2, being highly flammable and having one of the lowest autoignition temperatures, cannot be transported easily using commercial means. Worldwide exports of this chemical are negligible.
Johnson Matthey's sister company Alfa Aesar was the first company to introduce carbon disulfide in the form of pressurized bottle containing a solution of pressurized nitrogen, coupling agent, stabilizer, and carbon disulfide, with an active carbon disulfide content of 85%. Dilution with nitrogen rendered contents nonflammable.citation needed
At high levels, carbon disulfide may be life-threatening because it affects the nervous system. Significant safety data comes from the viscose rayon industry, where both carbon disulfide as well as small amounts of H2S may be present.
- Holleman, A. F.; Wiberg, E. (2001), Inorganic Chemistry, San Diego: Academic Press, ISBN 0-12-352651-5
- Werner, H. (1982). "Novel Coordination Compounds formed from CS2 and Heteroallenes". Coordination Chemistry Reviews 43: 165–185. doi:10.1016/S0010-8545(00)82095-0.
- Smeulders, MJ.; Barends, TR.; Pol, A.; Scherer, A.; Zandvoort, MH.; Udvarhelyi, A.; Khadem, AF.; Menzel, A.; Hermans, J.; Shoeman, RL.; Wessels, HJ.; Van den Heuvel, LP.; Russ, L.; Schlichting, I.; Jetten, MS.; Op den Camp, HJ. “Evolution of a New Enzyme for Carbon Disulphide Conversion by an AcidothermophilicArchaeon” Nature, 2011, 487, 412-416. doi:10.1038/nature10464
- Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth–Heinemann. ISBN 0080379419.
- Worthing, C. R.; Hance. R. J. (1991). The Pesticide Manual, A World Compendium (9th ed.). British Crop Protection Council. ISBN 9780948404429.
- "Carbon Disulfide". Akzo Nobel.
- Park, T.-J.; Banerjee, S.; Hemraj-Benny, T.; Wong, S. S. (2006). "Purification strategies and purity visualization techniques for single-walled carbon nanotubes". Journal of Materials Chemistry 16 (2): 141–154. doi:10.1039/b510858f.