Difference between revisions of "Carbon disulfide"

Revision as of 14:44, 3 June 2018

Carbon disulfide is a colorless volatile liquid with the formula CS₂, useful as a non-polar solvent.

Properties

Chemical

Carbon disulfide is highly flammable and will burn in air to release carbon and sulfur dioxides.

Chlorination of CS₂ yields carbon tetrachloride and sulfur dichloride:

CS₂ + 3 Cl₂ → CCl₄ + S₂Cl₂

Physical

Carbon disulfide is a colorless liquid, with an chloroform like smell when pure. Impure CS₂ has a yellowish color and has a putrid smell. It is insoluble in water, but soluble in many organic solvents, such as benzene, ethanol, diethyl ether, carbon tetrachloride, chloroform. It's poorly soluble in formic acid. CS₂ boils at 46.24 °C and freezes at −111.61 °C. It has a low autoignition temperature for a solvent, of only 102 °C.

Availability

Carbon disulfide is sold by chemical suppliers, however there appears to be no sellers on Ebay or Amazon. It is a hard to find reagent.

Preparation

There are many ways to synthesize CS₂, most if not all tend to produce plenty of side products, which means that the product will be impure and have a bad smell. Some processes have low yield.

The first method, involves the reaction of sulfur vapors with carbon (or coke, anthracite, or any other coal) at 900°C. The resulting vapors are condensed and sulfur disulfide is purified. BromicAcid managed to synthesize only a few ml using this method. A few years later, garagechemist in collaboration with Len1, tried to improve the said method, using a tube furnace. It yielded around 44 g of CS₂. myst32YT mas also made a small amount of carbon disulfide.^[1]

Another method, that works at lower temperatures (600 °C), utilizes methane as the carbon source in the presence of silica gel or alumina catalysts:

2 CH₄ + S₈ → 2 CS₂ + 4 H₂S^[2]

Another method involves the reaction of carbon tetrachloride with sulfur, between 120-220 °C, in the presence of a catalyst such as copper chloride, iron chloride, aluminium chloride.^[3]

The thermal decomposition of ammonium thiocyanate, preferably in an inert atmosphere yields carbon disulfide, ammonia, hydrogen sulfide, leaving a residue of guanidinium thiocyanate. This reaction produces a fairly pure compound, though the starting products are not particularly cheap. Other thiocyanates can also be used. An approximate reaction of the decomposition is shown below:

NH₄SCN → CS₂ + NH₃ + H₂S + CH₆N₃SCN

Reacting sulfur or sulfur dioxide vapors with carbon dioxide at 800 °C in the presence of alumina catalyst will also yield carbon disulfide. Carbonyl sulfide may also form as a side product.^[4][5]

A mixture of acetylene and sulfur vapor at temperatures between 325-650 °C will also yield carbon disulfide. Pyrite can also be used instead of sulfur.^[6]

A different way involves the reaction of carbon monoxide with sulfur, in the presence of a catalyst such as iron, iron(III) sulfide, at temperatures between 400 - 500 °C.^[7] The same reaction can also be carried out at 500 °C in the presence of silica gel.^[8]

The reaction of calcium carbide with sulfur at at 500 °C.^[9] The same reaction can also occur at temperatures between 250 - 360 °C, with a different yield.^[10]

Another method described in literature is the reaction of lead(II) sulfide with carbon monoxide, in a furnace, at high temperature.^[11]

Carbon disulfide can also be obtained in traces by reacting benzene with sulfur dioxide, at 500°C. It also produces many byproducts,such as dithiobenzene, carbon dioxide, carbonyl sulfide, some free oxygen, and some unknown polymeric residue.^[12] The reaction can be improved by using a vanadium pentoxide/alumina catalyst, the reaction taking place at 1000-1200 °C.^[13]

Pyrolysis of scrap tires also gives carbon disulfide, although separating it from the mixture is not very practical.^[14]

Projects

• Sulfur extraction and purification
• Barking dog reaction
• Make carbon tetrachloride
• Make KS Fluid
• Solvent for synthesis of phosphorus triiodide
• Synthesize trithiocarbonates
• Prepare xanthate salts

Handling

Safety

Carbon disulfide has moderate toxicity. It is an irritant to the eyes and skin. CS₂ is however extremely volatile and flammable.^[15]

Storage

Carbon disulfide should be stored in closed bottles away from any heat source. Due to it's high volatility its best kept in a cold place. The bottle should be open periodically to prevent a pressure build-up.

Disposal

Carbon disulfide can be burned, although this will produce toxic sulfur dioxide gas.

References

1. ↑ https://www.youtube.com/watch?v=IkBFlPagRgA
2. ↑ http://pubs.acs.org/doi/abs/10.1021/ie50642a007
3. ↑ Fomin, W. A., Zhurnal Obshchei Khimii, 1936, Vol. 6, p. 852 - 854
4. ↑ http://onlinelibrary.wiley.com/doi/10.1002/ange.19310442003/abstract
5. ↑ http://onlinelibrary.wiley.com/doi/10.1002/ange.19320455202/abstract
6. ↑ Bulletin de la Societe Chimique de France, 1908, Vol. <4> 3, p. 151
7. ↑ DE398322 C
8. ↑ http://pubs.acs.org/doi/abs/10.1021/ie50584a043
9. ↑ http://onlinelibrary.wiley.com/doi/10.1002/ange.19280412607/abstract
10. ↑ Moissan, Comptes Rendus Hebdomadaires des Seances de l'Academie des Sciences (1894), Vol. 118, p. 502
11. ↑ http://pubs.rsc.org/en/content/articlelanding/1863/js/js8631600042#!divAbstract
12. ↑ http://pubs.acs.org/doi/abs/10.1021/ja01510a062
13. ↑ http://pubs.rsc.org/en/content/articlelanding/1957/tf/tf9575300972#!divAbstract
14. ↑ http://pubs.acs.org/doi/abs/10.1021/es990883y
15. ↑ http://www.sciencelab.com/msds.php?msdsId=9927125

Relevant Sciencemadness threads

• Carbon Disulfide Preparation
• Carbon Disulfide from sulfur and charcoal
• Fun/cool reactions/experiments to do with CS2?