Carbonyl sulfide

• Carbonyl
• Carbonoxysulfid
• COS

Colorless, foul- smelling gas

Gaseous

• 2.72 g · l-1 (0 ° C, 1013 hPa)
• 1.18 g · cm -3 (liquid at boiling point )

-139 ° C

-50 ° C

1.13 MPa ( 20 ° C)

Poorly in water ( 1.45 g · l -1)

1.24 ( -87 ° C)

Risk

-142.0 KJ / mol

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Carbonyl sulfide is a colorless, flammable, poisonous gas with an unpleasant odor. However Chemically pure COS should be odorless. It plays a particularly important role in atmospheric chemistry.

History

It was discovered in 1867 by the Hungarian chemist Carl von Than. In 1868, of Than for his work on the absorption coefficient of the COS Lieben Prize.

Occurrence

Carbonyl sulfide is produced mainly in the atmosphere. However, it is also present in natural gas, volcanic gases, biogas, and as a by- product in the chemical industry.

Production and representation

In the laboratory, carbonyl sulfide can be represented from potassium thiocyanate and sulfuric acid. In addition to potassium hydrogen sulfate and ammonium bisulfate is also produced gaseous COS with various impurities, it must therefore be cleaned. Another pathway is the reaction of carbon monoxide with sulfur vapor in glowing tubes:

A way for the synthesis of COS is the incomplete oxidation of a stoichiometric mixture of carbon and sulfur with oxygen according to the reaction equation:

Properties

The carbonyl sulfide molecule has a line rare molecular structure. In this case, a carbon atom is linked in each case via a double bond with the sulfur and oxygen. It is isoelectronic to carbon dioxide and carbon disulfide.

In air, it burns to carbon dioxide and sulfur dioxide:

With water or steam it hydrolyzed to carbon dioxide and hydrogen sulfide:

Carbonyl sulfide has a critical temperature of 101.8 ° C and a critical pressure of 63.5 bar.

Atmospheric chemistry

Carbonyl is an aerosol formation in the atmosphere ( and thus the climate ) influencing gas and the dominant sulfur gas in the atmosphere. This is due to its longevity in the atmosphere. It is as nitrous oxide (laughing gas ) is not degraded in the troposphere and thus moves into the stratosphere. There, it is converted to sulfate aerosols, which reflect sunlight back into space and thus contribute to the cooling of our planet.

Made it in nature mainly by the action of sunlight on sulfur-containing organic compounds (eg, dimethyl sulfoxide and CS) in the upper layers of the oceans (especially coastal areas).

Use

Carbonyl sulfide is used for container fumigation.

Biological Significance

Many plants take carbonyl sulfide in the day on the organic sulfur source. The connection also plays in the formation of protein chains of amino acids play a role and it is believed that it should play an important role in the origin of life.