Carbonyl sulfide

Chembox new
Name = Carbonyl sulfide
ImageFile = Carbonyl-sulfide-2D-dimensions.png ImageName = Carbonyl sulfide
ImageFile1 = Carbonyl-sulfide-3D-vdW.png ImageName1 = Space-filling 3D model of carbonyl sulfide
IUPACName = carbonyl sulfide
Section1 = Chembox Identifiers
CASOther = 463-58-1
SMILES = O=C=S
Section2 = Chembox Properties
Formula = COS
MolarMass = 60.07 g mol⁻¹
MeltingPt = −139 °C (134 K)
BoilingPt = −50 °C (223 K)
Density = 0.00251 g cm⁻³
Section7 = Chembox Hazards
NFPA-H = 3
NFPA-F = 4
NFPA-R =
ExternalMSDS = [http://ptcl.chem.ox.ac.uk/MSDS/CA/carbonyl_sulfide.html Carbonyl sulfide MSDS]
Section8 = Chembox Other
OtherCpds = Carbon dioxide
Carbon disulfide

Carbonyl sulfide is the chemical compound with the formula OCS. Commonly written as COS, it is a colourless gas with an unpleasant odor. It is a linear molecule consisting with a carbonyl group double bonded to a sulfur atom. Carbonyl sulfide can be considered to be a compound of carbon dioxide and carbon disulfide.

This compound is found to catalyze the formation of peptides from amino acids. This finding is an extension of the Miller-Urey experiment and it is suggested that carbonyl sulfide played a significant role in the origin of life. [cite journal
title = Carbonyl Sulfide–Mediated Prebiotic Formation of Peptides
author = Luke Leman, Leslie Orgel, M. Reza Ghadiri
journal = Science
year = 2004
volume = 306
issue = 5694
pages = 283–286
doi = 10.1126/science.1102722
pmid = 15472077]

Occurrence and applications

Carbonyl sulfide is the major sulfur compound naturally present in the atmosphere at 0.5 (± 0.05) ppb because it is emitted from volcanos and deep sea vents. As such it participates in the global sulfur cycle. It is also present in foodstuffs such as cheese and prepared vegetables of the cabbage family. Traces of COS are naturally present in grains and seeds in the range of 0.05-0.1 mg kg⁻¹. It is a significant sulfur-containing impurity in synthesis gas.

Measurements on the Antarctica ice cores provide a detailed picture of OCS concentrations from 1640 to the present day separating anthropogenic and non-anthropogenic sulfur sources. Carbonyl sulfide is transported into the stratospheric sulfate layer where it is oxidized to sulfuric acid.

Carbonyl sulfide is a potential fumigant and a replacement for methyl bromide and phosphine. Carbonyl sulfide has been observed in interstellar medium.

ynthesis

It was first described in 1841, [cite journal
author = Couërbe, J. P.
title = Ueber den Schwefelkohlenstoff
journal = Journal für Praktische Chemie
year = 1841
volume = 23
pages = 83–124
doi = 10.1002/prac.18410230105] but was apparently mischaracterized as a mixture of carbon dioxide and hydrogensulfide. Carl von Than first characterized the subtance first in 1867. It forms when carbon monoxide reacts with elemental sulfur. This reaction reverses above 1200 K. A laboratory synthesis entails the reaction potassium thiocyanate and sulfuric acid. The resulting gas contains significant amounts of byproducts and requires purification. [cite journal
title = The Chemistry of Carbonyl sulfide
author = Ferm R. J.
journal = Chemical Reviews
year = 1957
volume = 57
issue = 4
pages = 621–640
doi = 10.1021/cr50016a002] :KNCS + 2 H₂SO₄ + H₂O → KHSO₄ + NH₄HSO₄ + COS

References

Further reading

*cite journal
title = COS and C₃S₂: The Discovery and Chemistry of Two Important Inorganic Sulfur Compounds
author = Beck, M. T.; Kauffman, G. B.
journal = Polyhedron
year = 1985
volume = 4
issue = 5
pages = 775–781
doi = 10.1016/S0277-5387(00)87025-4
*cite journal
title = The possible importance of COS for the sulfate layer of the stratosphere
author = Crutzen, P.
journal = Geophys. Res. Lett.
year = 1976
volume = 3
issue =
pages = 73–76
doi =10.1029/GL003i002p00073
*cite journal
title = Carbonyl sulfide: A review of its chemistry and properties
author = Svoronos P. D. N., Bruno T. J.
journal = Industrial & Engineering Chemistry Research
year = 2002
volume = 41
issue = 22
pages = 5321–5336
doi = 10.1021/ie020365n

External links

* [http://www.scripps.edu/newsandviews/e_20041011/ghadiri.html Carbonyl sulfide and origins of life]
* [http://www.cmdl.noaa.gov/hotitems/cos.html Carbonyl sulfide in ice cores]
* [http://mbao.org/altmet00/86wright.pdf Carbonyl sulfide as a potential fumigant]
* [http://amsglossary.allenpress.com/glossary/search?id=carbonyl-sulfide1 Carbonyl sulfide in the atmosphere]