Carbonyl sulfide is the chemical compound with the linear formula OCS. Normally written as COS as a chemical formula that does not imply its structure, it is a colourless flammable gas with an unpleasant odor. It is a linear molecule consisting of a carbonyl group double bonded to a sulfur atom. Carbonyl sulfide can be considered to be intermediate between carbon dioxide and carbon disulfide, both of which are valence isoelectronic with it.
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.
3D model (JSmol)
|Molar mass||60.075 g/mol|
|Melting point||−138.8 °C (−217.8 °F; 134.3 K)|
|Boiling point||−50.2 °C (−58.4 °F; 223.0 K)|
|0.376 g/100 mL (0 °C) |
0.125 g/100 mL (25 °C)
|Solubility||very soluble in KOH, CS2 |
soluble in alcohol, toluene
Heat capacity (C)
|41.5 J/mol K|
|231.5 J/mol K|
Std enthalpy of
|Safety data sheet||Carbonyl sulfide MSDS|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Carbonyl sulfide is the most abundant sulfur compound naturally present in the atmosphere, at 0.5±0.05 ppb, because it is emitted from oceans, volcanoes and deep sea vents. As such, it is a significant compound in the global sulfur cycle. Measurements on the Antarctica ice cores and from air trapped in snow above glaciers (firn air) have provided a detailed picture of OCS concentrations from 1640 to the present day and allow an understanding of the relative importance of anthropogenic and non-anthropogenic sources of this gas to the atmosphere. Some carbonyl sulfide that is transported into the stratospheric sulfate layer is oxidized to sulfuric acid. Sulfuric acid forms particulate which affects energy balance due to light scattering. The long atmospheric lifetime of COS makes it the major source of stratospheric sulfate, though sulfur dioxide from volcanic activity can be significant too. Carbonyl sulfide is also removed from the atmosphere by terrestrial vegetation by enzymes associated with the uptake of carbon dioxide during photosynthesis, and by hydrolysis in ocean waters. Loss processes, such as these, limit the persistence (or lifetime) of a molecule of COS in the atmosphere to a few years.
The largest man-made sources of carbonyl sulfide release include its primary use as a chemical intermediate and as a byproduct of carbon disulfide production; however, it is also released from automobiles and their tire wear., coal-fired power plants, coking ovens, biomass combustion, fish processing, combustion of refuse and plastics, petroleum manufacture, and manufacture of synthetic fibers, starch, and rubber. The average total worldwide release of carbonyl sulfide to the atmosphere has been estimated at about 3 million tons/year, of which less than one third was related to human activity. It is also a significant sulfur-containing impurity in synthesis gas.
Carbonyl sulfide has been observed in the interstellar medium (see also List of molecules in interstellar space), in comet 67P and in the atmosphere of Venus, where, because of the difficulty of producing COS inorganically, it is considered a possible indicator of life.
Carbonyl sulfide is used as an intermediate in the production of thiocarbamate herbicides. Carbonyl sulfide is a potential alternative fumigant to methyl bromide and phosphine. In some cases, however, residues on the grain result in flavours that are unacceptable to consumers, e.g. barley used for brewing. Carbonyl sulfide is readily converted to the gaseous signaling molecule hydrogen sulfide by carbonic anhydrase enzymes in plants and mammals. Because of this chemistry, the release of carbonyl sulfide from small organic molecules has been identified as a strategy for delivering hydrogen sulfide in different biological contexts. In ecosystem science, carbonyl sulfide is increasingly often being used to describe the rate of the photosynthesis.
Carbonyl sulfide was first described in 1841, but was apparently mischaracterized as a mixture of carbon dioxide and hydrogen sulfide. Carl von Than first characterized the substance in 1867. It forms when carbon monoxide reacts with molten sulfur. This reaction reverses above 1200 K (930 °C; 1700 °F). A laboratory synthesis entails the reaction potassium thiocyanate and sulfuric acid. The resulting gas contains significant amounts of byproducts and requires purification.
As of 1994, limited information existed on the acute toxicity of carbonyl sulfide in humans and in animals. High concentrations (>1000 ppm) can cause sudden collapse, convulsions, and death from respiratory paralysis. Occasional fatalities have been reported, practically without local irritation or olfactory warning. In tests with rats, 50% animals died when exposed to 1400 ppm of COS for 90 minutes, or at 3000 ppm for 9 minutes. Limited studies with laboratory animals also suggest that continued inhalation of low concentrations (~50 ppm for up to 12 weeks) does not affect the lungs or the heart.
Károly Antal Than de Apát – also called as Carl von Than – (20 December 1834 – 5 July 1908) was a Hungarian chemist who discovered carbonyl sulfide in 1867.Chinese drywall
"Chinese drywall" refers to an environmental health issue involving defective drywall manufactured in China, imported to the United States and used in residential construction between 2001 and 2009 — affecting "an estimated 100,000 homes in more than 20 states."In samples of contaminated drywall, laboratory tests will detect off-gassing of volatile chemicals and sulfurous gases — including carbon disulfide, carbonyl sulfide, and hydrogen sulfide. The emissions worsen as temperature and humidity rise, will give off a sulfuric (rotten egg) odor and will cause copper surfaces to turn black and powdery, a chemical process indicative of a hydrogen sulfide reaction and an early indication of contaminated drywall. Copper pipes, electrical wiring, and air conditioner coils are affected, as well as silver jewelry.
Homeowners have reported health symptoms including respiratory problems such as asthma attacks, chronic coughing and difficulty breathing, as well as chronic headaches and sinus issues.Chugaev elimination
The Chugaev elimination is a chemical reaction that involves the elimination of water from alcohols to produce alkenes. The intermediate is a xanthate. It is named for its discoverer, the Russian chemist Lev Aleksandrovich Chugaev (1873-1922), who first reported the reaction sequence in 1899.
In the first step, a xanthate salt is formed out of the alkoxide and carbon disulfide (CS2). With the addition of iodomethane, the alkoxide is transformed into a methyl xanthate.
At about 200 °C, the alkene is formed by an intramolecular elimination. In a 6-membered cyclic transition state the hydrogen atom is removed from the carbon atom β to the xanthate oxygen in a syn-elimination. The side product decomposes to carbonyl sulfide (OCS) and methanethiol.
The Chugaev elimination is similar in mechanism to other thermal elimination reactions such as the Cope elimination and ester pyrolysis. Xanthates typically undergo elimination from 120 to 200 °C, while esters typically require 400 to 500 °C and amine oxides routinely react between 80 and 160 °C.Circumstellar envelope
A circumstellar envelope (CSE) is a part of a star that has a roughly spherical shape and is not gravitationally bound to the star core. Usually circumstellar envelopes are formed from the dense stellar wind, or they are present before the formation of the star. Circumstellar envelopes of old stars (Mira variables and OH/IR stars) eventually evolve into protoplanetary nebulae, and circumstellar envelopes of young stellar objects evolve into circumstellar discs.Compounds of carbon
Compounds of carbon are defined as chemical substances containing carbon. More compounds of carbon exist than any other chemical element except for hydrogen. Organic carbon compounds are far more numerous than inorganic carbon compounds. In general bonds of carbon with other elements are covalent bonds. Carbon is tetravalent but carbon free radicals and carbenes occur as short-lived intermediates. Ions of carbon are carbocations and carbanions are also short-lived. An important carbon property is catenation as the ability to form long carbon chains and rings.Intergalactic dust
Intergalactic dust is cosmic dust in between galaxies in intergalactic space. Evidence for intergalactic dust has been suggested as early as 1949, and study of it grew throughout the late 20th century. There are large variations in the distribution of intergalactic dust. The dust may affect intergalactic distance measurements, such as to supernova and quasars in other galaxies.Intergalactic dust can form intergalactic dust clouds, known to exist around some galaxies since the 1960s. By the 1980s, at least four intergalactic dust clouds had been discovered within several megaparsec (Mpc) of the Milky Way galaxy, exemplified by the Okroy cloud.In February 2014, NASA announced a greatly upgraded database for tracking polycyclic aromatic hydrocarbons (PAHs) in the universe. According to scientists, more than 20% of the carbon in the universe may be associated with PAHs, possible starting materials for the formation of life. PAHs seem to have been formed as early as two billion years after the Big Bang, are widespread throughout the universe, and are associated with new stars and exoplanets.Interstellar ice
Interstellar ice consists of grains of volatiles in the ice phase that form in the interstellar medium. Ice and dust grains form the primary material out of which the Solar System was formed. Grains of ice are found in the dense regions of molecular clouds, where new stars are formed. Temperatures in these regions can be as low as 10 K (−263 °C; −442 °F), allowing molecules that collide with grains to form an icy mantle. Thereafter, atoms undergo thermal motion across the surface, eventually forming bonds with other atoms. This results in the formation of water and methanol. Indeed, the ices are dominated by water and methanol, as well as ammonia, carbon monoxide and carbon dioxide. Frozen formaldehyde and molecular hydrogen may also be present. Found in lower abundances are nitriles, ketones, esters and carbonyl sulfide. The mantles of interstellar ice grains are generally amorphous, only becoming crystalline in the presence of a star.The composition of interstellar ice can be determined through its infrared spectrum. As starlight passes through a molecular cloud containing ice, molecules in the cloud absorb energy. This adsorption occurs at the characteristic frequencies of vibration of the gas and dust. Ice features in the cloud are relatively prominently in this spectra, and the composition of the ice can be determined by comparison with samples of ice materials on Earth. In the sites directly observable from Earth, around 60–70% of the interstellar ice consists of water, which displays a strong emission at 3.05 μm from stretching of the O–H bond.In September 2012, NASA scientists reported that polycyclic aromatic hydrocarbons (PAHs), subjected to interstellar medium (ISM) conditions, are transformed, through hydrogenation, oxygenation and hydroxylation, to more complex organics - "a step along the path toward amino acids and nucleotides, the raw materials of proteins and DNA, respectively". Further, as a result of these transformations, the PAHs lose their spectroscopic signature which could be one of the reasons "for the lack of PAH detection in interstellar ice grains, particularly the outer regions of cold, dense clouds or the upper molecular layers of protoplanetary disks."Ketenimine
Ketenimines are a group of organic compounds sharing a common functional group with the general structure R1R2C=C=NR3. A ketenimine is a cumulated alkene and imine and is related to an allene and a ketene.
The parent compound is ketenimine or CH2CNH. The most recent work by Bane et al. investigates the rovibrational structure of the ν8 and ν12 bands in the high-resolution FTIR spectrum, complementing the earlier analysis of the pure rotational spectrum. This pair of Coriolis coupled bands provide a rare example where intensity sharing between bands yields sufficient intensity for an otherwise invisible band (ν12).Life on Venus
The speculation of life currently existing on Venus decreased significantly since the early 1960s, when spacecraft began studying Venus and it became clear that the conditions on Venus are extreme compared to those on Earth.
Venus's location closer to the Sun than Earth and the extreme greenhouse effect raising temperatures on the surface to nearly 735 K (462 °C), and the atmospheric pressure 90 times that of Earth, make water-based life as we know it unlikely on the surface of the planet. However, a few scientists have speculated that thermoacidophilic extremophile microorganisms might exist in the lower-temperature, acidic upper layers of the Venusian atmosphere.Methoxy group
A methoxy group is the functional group consisting of a methyl group bound to oxygen. This alkoxy group has the formula O–CH3. On a benzene ring, the Hammett equation classifies a methoxy substituent as an electron-donating group.NanoScale Corporation
NanoScale Corporation was a private US corporation, located in Manhattan, Kansas. It was founded by Dr. Kenneth J. Klabunde in 1995, as Nantek, Inc., to further develop and commercialize certain intellectual properties of Kansas State University. In January 2001, the Company’s name was changed to NanoScale Materials, Inc. They were reincorporated in July 2007, as a Delaware corporation, with the current name NanoScale Corporation. NanoScale worked with a variety of private, commercial, and government customers. NanoScale developed, manufactured, and sold nano-crystalline metal oxides and other materials for a wide array of applications, including odor neutralization, hazardous chemical neutralization, and environmental remediation. Scientists affiliated with NanoScale Corporation have collaborated to write, and publish, many scientific papers and publications in the subjects of material science and advanced chemistry nanotechnology. They closed down following wire-fraud.Their government contract history is extensive, totaling over 18.6 million dollars between 2000 and 2008, specializing in engineering, physical sciences, and biological science. The company has a history of multiple Small Business Innovation Research (SBIR) awarded projects with the US Army, in a wide range of applications. One such project focused on decontamination wipes for war fighters to use when coming in contact with chemical warfare agents, and acid-gas remediation research to treat hydrogen sulfide (H2S), carbonyl sulfide (COS), and other chemical compounds. Another project sponsored by the US EPA, SBIR division, focused on nano-crystalline materials for the hot fuel-gas clean-up applications, such as zinc oxide-based sorbents for moderate-temperature, high-capacity hydrogen sulfide and carbonyl sulfide clean-up, supported copper oxide sorbents for high-temperature H2S, COS, and possibly mercury clean-up, and nickel
-based supported catalysts for high temperature ammonia (NH3) and hydrogen cyanide (HCN) decomposition. The US Army SBIR Newsletter stated, "In addition to all of the first response applications for FAST-ACT, the technology is being further developed for decontamination wipes, residue-free wipes, and is currently utilized in commercial odor elimination products such as OdorKlenz and Nano-Zorb." Altogether, NanoScale Corporation continues to research, develop, and produce products for environmental remediation, often at the actual nano scale.Phosphorus mononitride
Phosphorus mononitride is an inorganic compound with the chemical formula PN. Containing only phosphorus and nitrogen, this material is classified as a binary nitride.
It is the first identified phosphorus compound in the interstellar medium.It is an important molecule in interstellar medium and the atmospheres of Jupiter and Saturn.Polyarc reactor
The Polyarc reactor is a scientific instrument for the measurement of organic molecules. The reactor is paired with a flame ionization detector (FID) in a gas chromatograph (GC) to improve the sensitivity of the FID and give a uniform detector response for all organic molecules (GC-Polyarc/FID).
The reactor converts the carbon atoms of organic molecules in GC column effluents into methane before reaching the FID. The resulting detector response is uniform on a per carbon basis and allows the FID to have truly universal carbon sensitivity. GC-Polyarc/FID peak areas (integrated detector responses) are equivalent on a per carbon basis, thus eliminating the need for response factors and calibration standards. In addition, the GC-Polyarc/FID method improves the response of the FID to a number of molecules with traditionally poor/low response including, carbon monoxide (CO), carbon dioxide (CO2), carbon disulfide (CS2), carbonyl sulfide (COS), hydrogen cyanide (HCN), formamide (CH3NO), formaldehyde (CH2O) and formic acid (CH2O2), because these molecules are converted to methane.Stratospheric sulfur aerosols
Stratospheric sulfur aerosols are sulfur-rich particles which exist in the stratosphere region of the Earth's atmosphere. The layer of the atmosphere in which they exist is known as the Junge layer, or simply the stratospheric aerosol layer. These particles consist of a mixture of sulfuric acid and water. They are created naturally, such as by photochemical decomposition of sulfur-containing gases, e.g. carbonyl sulfide. When present in high levels, e.g. after a strong volcanic eruption such as Mount Pinatubo, they produce a cooling effect, by reflecting sunlight, and by modifying clouds as they fall out of the stratosphere. This cooling may persist for a few years before the particles fall out.
An aerosol is a suspension of fine solid particles or liquid droplets in a gas.
The sulfate particles or sulfuric acid droplets in the atmosphere are about 0.1 to 1.0 micrometer (a millionth of a meter) in diameter.
Sulfur aerosols are common in the troposphere as a result of pollution with sulfur dioxide from burning coal, and from natural processes. Volcanos are a major source of particles in the stratosphere as the force of the volcanic eruption propels sulfur-containing gases into the stratosphere. The relative influence of volcanoes on the Junge layer varies considerably according to the number and size of eruptions in any given time period, and also of quantities of sulfur compounds released. Only stratovolcanoes containing primarily felsic magmas are responsible for these fluxes, as mafic magma erupted in shield volcanoes doesn't result in plumes which reach the stratosphere.
Creating stratospheric sulfur aerosols deliberately is a proposed geoengineering technique which offers a possible solution to some of the problems caused by global warming. However, this will not be without side effects and it has been suggested that the cure may be worse than the disease.Sulfanyl
Sulfanyl (HS•), also known as the mercapto radical, hydrosulfide radical, or hydridosulfur, is a simple radical molecule consisting of one hydrogen and one sulfur atom. The radical appears in metabolism in organisms as H2S is detoxified. Sulfanyl is one of the top three sulfur-containing gasses in gas giants such as Jupiter and is very likely to be found in brown dwarfs and cool stars. It was originally discovered by Margaret N. Lewis and John U. White at the University of California in 1939. They observed molecular absorption bands around 325 nm belonging to the system designated by 2Σ+ ← 2Πi. They generated the radical by means of a radio frequency discharge in hydrogen sulfide. HS• is formed during the degradation of hydrogen sulfide in the atmosphere of the Earth. This may be a deliberate action to destroy odours or a natural phenomenon.The organic analogue of sulfanyl is thiyl radical with the formula RS., where R = alkyl or aryl.Thioacyl chloride
In organic chemistry, thioacyl chloride is a functional group of the type RC(S)Cl, where R is an organic substituent. Thioacyl chlorides are analogous to acid chlorides, but much rarer and less robust. The best studied is thiobenzoyl chloride, a purple oil first prepared by chlorination of dithiobenzoic acid with a combination of chlorine and thionyl chloride. A more modern preparation employs phosgene as the chlorinating agent, this also generates carbonyl sulfide as a by-product.
PhCS2H + COCl2 → PhC(S)Cl + HCl + COSThe compounds are more stable with electron-releasing substituents.Thiocarbamate
Thiocarbamates are a family of organosulfur compounds. As the name suggests, they are sulphur analogues of carbamates. There are two isomeric forms of thiocarbamate esters: O-thiocarbamates, ROC(=S)NR2, and S-thiocarbamates, RSC(=O)NR2.Thiocyanate hydrolase
In enzymology, a thiocyanate hydrolase (EC 188.8.131.52) is an enzyme that catalyzes the chemical reaction
Thus, the two substrates of this enzyme are thiocyanate and H2O, whereas its 3 products are carbonyl sulfide, NH3, and HO-.
This enzyme belongs to the family of hydrolases, those acting on carbon-nitrogen bonds other than peptide bonds, specifically in nitriles. The systematic name of this enzyme class is thiocyanate aminohydrolase.
|Oxides and related|