Tetrahydrothiophene is an

organosulfur compound Organosulfur compounds are organic compounds that contain sulfur. They are often associated with foul odors, but many of the sweetest compounds known are organosulfur derivatives, e.g., saccharin. Nature abounds with organosulfur compounds—sulf ...

with the formula (CH₂)₄S. The molecule consists of a five-membered saturated ring with four

methylene Methylene may refer to: * Methylene group or methylene bridge (CH2< or equivalently -CH2-), a part of a molecule connected to the rest of the molecule by two single bonds. * An older name for methylidene (=CH2), a part of a molecule connected t ...

groups and a

sulfur Sulfur (or sulphur in British English) is a chemical element with the symbol S and atomic number 16. It is abundant, multivalent and nonmetallic. Under normal conditions, sulfur atoms form cyclic octatomic molecules with a chemical formul ...

atom. It is the

saturated Saturation, saturated, unsaturation or unsaturated may refer to: Chemistry * Saturation, a property of organic compounds referring to carbon-carbon bonds **Saturated and unsaturated compounds **Degree of unsaturation **Saturated fat or fatty acid ...

analog Analog or analogue may refer to: Computing and electronics * Analog signal, in which information is encoded in a continuous variable ** Analog device, an apparatus that operates on analog signals *** Analog electronics, circuits which use analo ...

thiophene Thiophene is a heterocyclic compound with the formula C4H4S. Consisting of a planar five-membered ring, it is aromatic as indicated by its extensive substitution reactions. It is a colorless liquid with a benzene-like odor. In most of its react ...

. It is a volatile, colorless liquid with an intensely unpleasant

odor An odor (American English) or odour (Commonwealth English; see spelling differences) is caused by one or more volatilized chemical compounds that are generally found in low concentrations that humans and animals can perceive via their sense ...

. It is also known as thiophane, thiolane, or THT. While THT is not particularly common, the vitamin biotin is essential for life in aerobic organisms.

Synthesis and reactions

Tetrahydrothiophene is prepared by the reaction of

tetrahydrofuran Tetrahydrofuran (THF), or oxolane, is an organic compound with the formula (CH2)4O. The compound is classified as heterocyclic compound, specifically a cyclic ether. It is a colorless, water- miscible organic liquid with low viscosity. It is ...

with

hydrogen sulfide Hydrogen sulfide is a chemical compound with the formula . It is a colorless chalcogen-hydride gas, and is poisonous, corrosive, and flammable, with trace amounts in ambient atmosphere having a characteristic foul odor of rotten eggs. The und ...

. This vapor-phase reaction is catalyzed by alumina and other heterogenous acid catalysts. This compound is a

ligand In coordination chemistry, a ligand is an ion or molecule ( functional group) that binds to a central metal atom to form a coordination complex. The bonding with the metal generally involves formal donation of one or more of the ligand's ele ...

coordination chemistry A coordination complex consists of a central atom or ion, which is usually metallic and is called the ''coordination centre'', and a surrounding array of chemical bond, bound molecules or ions, that are in turn known as ''ligands'' or complexing ...

, an example being the complex

chloro(tetrahydrothiophene)gold(I) Chloro(tetrahydrothiophene)gold(I), abbreviated (tht)AuCl, is a coordination complex of gold. Like the dimethyl sulfide analog, this compound is used as a entry point to gold chemistry. The tetrahydrothiophene ligand is labile and is readily subst ...

. Oxidation of THT gives the sulfone

sulfolane Sulfolane (also ''tetramethylene sulfone'', systematic name: 1λ6-thiolane-1,1-dione) is an organosulfur compound, formally a cyclic sulfone, with the formula (CH2)4SO2. It is a colorless liquid commonly used in the chemical industry as a solvent ...

, which is of interest as a polar, odorless solvent: : Sulfolane is, however, more conventionally prepared from

butadiene 1,3-Butadiene () is the organic compound with the formula (CH2=CH)2. It is a colorless gas that is easily condensed to a liquid. It is important industrially as a precursor to synthetic rubber. The molecule can be viewed as the union of two vin ...

Natural occurrence

Both unsubstituted and substituted tetrahydrothiophenes are reported to occur in nature. For example, tetrahydrothiophene occurs as a volatile from ''

Eruca sativa Arugula (American English) or rocket (Commonwealth English) (''Eruca vesicaria''; syns. ''Eruca sativa'' Mill., ''E. vesicaria'' subsp. ''sativa'' (Miller) Thell., ''Brassica eruca'' L.) is an edible annual plant in the family Brassicaceae used ...

'' Mill. (salad rocket) while monocyclic substituted tetrahydrothiophenes have been isolated from ''

Allium fistulosum ''Allium fistulosum'', the Welsh onion, also commonly called bunching onion, long green onion, Japanese bunching onion, and spring onion, is a species of perennial plant, often considered to be a kind of scallion. The species is very similar ...

'' 'Kujou', ''

Allium sativum Garlic (''Allium sativum'') is a species of bulbous flowering plant in the genus '' Allium''. Its close relatives include the onion, shallot, leek, chive, Welsh onion and Chinese onion. It is native to South Asia, Central Asia and nort ...

'' (garlic), ''

Allium cepa An onion (''Allium cepa'' L., from Latin ''cepa'' meaning "onion"), also known as the bulb onion or common onion, is a vegetable that is the most widely cultivated species of the genus ''Allium''. The shallot is a botanical variety of the onion ...

'' (onion), ''

Allium schoenoprasum Chives, scientific name ''Allium schoenoprasum'', is a species of flowering plant in the family Amaryllidaceae that produces edible leaves and flowers. Their close relatives include the common onions, garlic, shallot, leek, scallion, and ...

'' (chives), and '' Salacia prinoides.''

Albomycin Albomycins are a group of naturally occurring antibiotics belonging to the class of sideromycins, which are "compounds composed of iron carriers called siderophores linked to antibiotic moieties". They are particularly effective against Gram-nega ...

s are a group of tetrahydrothiophene-ring containing antibiotics from

streptomyces ''Streptomyces'' is the largest genus of Actinomycetota and the type genus of the family Streptomycetaceae. Over 500 species of ''Streptomyces'' bacteria have been described. As with the other Actinomycetota, streptomycetes are gram-positive, ...

while biotin and

neothiobinupharidine Neothiobinupharidine is a dimeric thiaspirane alkaloid isolated from the dwarf water lily ''Nuphar pumila ''Nuphar pumila'', the least water-lily or small yellow pond-lily, is an aquatic perennial plant in the Nymphaeaceae family. It is als ...

(and other

nuphar ''Nuphar'' is a genus of aquatic plants in the family Nymphaeaceae, with a temperate to subarctic Northern Hemisphere distribution. Common names include water-lily (Eurasian species; shared with many other genera in the same family), pond-lily, a ...

alkaloids ), are examples of bicyclic and polycyclic tetrahydrothiophene-ring containing natural products, respectively.

Applications

Because of its smell, tetrahydrothiophene has been used as an

odorant An aroma compound, also known as an odorant, aroma, fragrance or flavoring, is a chemical compound that has a smell or odor. For an individual chemical or class of chemical compounds to impart a smell or fragrance, it must be sufficiently vo ...

in LPG, albeit no longer in North America. It is also used as an odorant for

natural gas Natural gas (also called fossil gas or simply gas) is a naturally occurring mixture of gaseous hydrocarbons consisting primarily of methane in addition to various smaller amounts of other higher alkanes. Low levels of trace gases like carbon ...

, usually in mixtures containing ''tert''-butylthiol. Tetrahydrothiophene is a Lewis base classified as a soft base and its donor properties are discussed in the ECW model.

References

{{reflist Thiolanes Solvents Foul-smelling chemicals

Synthesis and reactions

Natural occurrence

Applications

See also

References