- Carbon disulfide
Carbon disulfide Identifiers CAS number PubChem ChemSpider UNII EC number UN number 1131 KEGG ChEBI RTECS number FF6650000 Jmol-3D images Image 1 Properties Molecular formula CS2 Molar mass 76.139 g/mol Appearance colorless liquid
Density 1.261 g/cm3 Melting point
-110.8 °C, 162 K, -167 °F
46.3 °C, 319 K, 115 °F
Solubility in water 2.9 g/kg (20 °C) Refractive index (nD) 1.6295 Structure Molecular shape Linear Dipole moment zero Hazards MSDS External MSDS EU Index 006-003-00-3 EU classification Extremely Flammable (F+)
Repr. Cat. 3
R-phrases , , , , S-phrases , , , , NFPA 704 Flash point -30 °C Autoignition
90 °C Explosive limits 1.3–50% LD50 3188 mg/kg Related compounds Related compounds Carbon dioxide
Supplementary data page Structure and
n, εr, etc. Thermodynamic
Solid, liquid, gas
Spectral data UV, IR, NMR, MS (what is: /?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
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 Occurrence and manufacture
- 2 Reactions
- 3 Commercial availability
- 4 Uses
- 5 Health effects
- 6 See also
- 7 References
- 8 External links
Occurrence and manufacture
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:
- 2CH4 + S8 → 2CS2 + 4H2S
The reaction is analogous to the combustion of methane. Although it is isoelectronic with carbon dioxide, CS2 is highly flammable:
- 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.
Addition of nucleophiles
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.
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.
Pressurized liquid nitrogen based sample
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.
Carbon disulfide is used as an insecticide for the fumigation of grains, nursery stock, in fresh fruit conservation and as a soil disinfectant against insects and nematodes.
The principal industrial uses of carbon disulfide are the manufacture of viscose rayon, cellophane film, carbon tetrachloride and xanthogenates and electronic vacuum tube. It is also used in the manufacture of Bamboo Fiber.
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.
- ^ a b c 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.
- ^ Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Oxford: Butterworth-Heinemann. ISBN 0080379419.
- ^ British Crop Protection Council (1987). The Pesticide Manual, A World Compendium, 8th Ed.
- ^ http://www.akzonobel.com/sulfurderivatives/products/carbon_disulfide/
- ^ J. Mat. Chem., 2006, 141-154 . doi:10.1039/b510858f
- ^ http://www.greencores.com/safety.html
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