organic chemistry Organic chemistry is a subdiscipline within chemistry involving the science, scientific study of the structure, properties, and reactions of organic compounds and organic matter, organic materials, i.e., matter in its various forms that contain ...

, an ethyl group (abbr. Et) is an

alkyl In organic chemistry, an alkyl group is an alkane missing one hydrogen. The term ''alkyl'' is intentionally unspecific to include many possible substitutions. An acyclic alkyl has the general formula of . A cycloalkyl group is derived from a cy ...

substituent In organic chemistry, a substituent is one or a group of atoms that replaces (one or more) atoms, thereby becoming a moiety in the resultant (new) molecule. The suffix ''-yl'' is used when naming organic compounds that contain a single bond r ...

with the

formula In science, a formula is a concise way of expressing information symbolically, as in a mathematical formula or a ''chemical formula''. The informal use of the term ''formula'' in science refers to the general construct of a relationship betwe ...

, derived from

ethane Ethane ( , ) is a naturally occurring Organic compound, organic chemical compound with chemical formula . At standard temperature and pressure, ethane is a colorless, odorless gas. Like many hydrocarbons, ethane is List of purification methods ...

(). ''Ethyl'' is used in the

International Union of Pure and Applied Chemistry The International Union of Pure and Applied Chemistry (IUPAC ) is an international federation of National Adhering Organizations working for the advancement of the chemical sciences, especially by developing nomenclature and terminology. It is ...

nomenclature of organic chemistry ''Nomenclature of Organic Chemistry'', commonly referred to by chemists as the ''Blue Book'', is a collection of recommendations on organic chemical nomenclature published at irregular intervals by the International Union of Pure and Applied C ...

for a saturated two-carbon

moiety Moiety may refer to: __NOTOC__ Anthropology * Moiety (kinship), either of two groups into which a society is divided ** A division of society in the Iroquois societal structure in North America ** An Australian Aboriginal kinship group ** Native Ha ...

in a molecule, while the prefix "''eth-''" is used to indicate the presence of two carbon atoms in the molecule.

Ethylation

Ethylation is the formation of a compound by introduction of the ethyl group. The most widely practiced example of this reaction is the ethylation of

benzene Benzene is an Organic compound, organic chemical compound with the Chemical formula#Molecular formula, molecular formula C6H6. The benzene molecule is composed of six carbon atoms joined in a planar hexagonal Ring (chemistry), ring with one hyd ...

with

ethylene Ethylene (IUPAC name: ethene) is a hydrocarbon which has the formula or . It is a colourless, flammable gas with a faint "sweet and musky" odour when pure. It is the simplest alkene (a hydrocarbon with carbon–carbon bond, carbon–carbon doub ...

to yield

ethylbenzene Ethylbenzene is an organic compound with the formula . It is a highly flammable, colorless liquid with an odor similar to that of gasoline. This monocyclic aromatic hydrocarbon is important in the petrochemical industry as a reaction intermediat ...

, a precursor to

styrene Styrene is an organic compound with the chemical formula C6H5CH=CH2. Its structure consists of a vinyl group as substituent on benzene. Styrene is a colorless, oily liquid, although aged samples can appear yellowish. The compound evaporates easi ...

, which is a precursor to

polystyrene Polystyrene (PS) is a synthetic polymer made from monomers of the aromatic hydrocarbon styrene. Polystyrene can be solid or foamed. General-purpose polystyrene is clear, hard, and brittle. It is an inexpensive resin per unit weight. It i ...

. Approximately 24.7 million tons of ethylbenzene were produced in 1999. :: EtC6H5route

Many ethyl-containing compounds are generated by

electrophilic In chemistry, an electrophile is a chemical species that forms bonds with nucleophiles by accepting an electron pair. Because electrophiles accept electrons, they are Lewis acids. Most electrophiles are positively charged, have an atom that carr ...

ethylation, i.e. treatment of

nucleophile In chemistry, a nucleophile is a chemical species that forms bonds by donating an electron pair. All molecules and ions with a free pair of electrons or at least one pi bond can act as nucleophiles. Because nucleophiles donate electrons, they are ...

s with sources of Et⁺.

Triethyloxonium tetrafluoroborate Triethyloxonium tetrafluoroborate is the organic oxonium compound with the formula . It is often called Meerwein's reagent or Meerwein's salt after its discoverer Hans Meerwein. Also well known and commercially available is the related trimet ...

t₃OF₄ is such a reagent. For good nucleophiles, less electrophilic reagents are employed, such as ethyl

halide In chemistry, a halide (rarely halogenide) is a binary chemical compound, of which one part is a halogen atom and the other part is an element or radical that is less electronegative (or more electropositive) than the halogen, to make a fl ...

Stereochemistry

In unsymmetrical ethylated compounds, the methylene protons in the ethyl substituent are

diastereotopic In stereochemistry, topicity is the stereochemical relationship between substituents and the structure to which they are attached. Depending on the relationship, such groups can be ''heterotopic'', ''homotopic'', ''enantiotopic'', or ''diastereotopi ...

. Chiral reagents are known to stereoselectively modify such substituents.

Etymology

The name of the group is derived from the

Aether Aether, æther or ether may refer to: Historical science and mythology * Aether (mythology), the personification of the bright upper sky * Aether (classical element), the material believed to fill the universe above the terrestrial sphere ** A ...

, the first-born Greek elemental god of air (and at that time a general term for any highly volatile compound) and " hyle", referring to "stuff". The name "ethyl" was coined in 1835 by the Swedish chemist

Jöns Jacob Berzelius Baron Jöns Jacob Berzelius (; 20 August 1779 – 7 August 1848) was a Swedish chemist. Berzelius is considered, along with Robert Boyle, John Dalton, and Antoine Lavoisier, to be one of the founders of modern chemistry. Berzelius became a memb ...

.In 1834, the German chemist

Justus Liebig Justus ''Freiherr'' von Liebig (12 May 1803 – 18 April 1873) was a German scientist who made major contributions to the theory, practice, and pedagogy of chemistry, as well as to agricultural and biological chemistry; he is considered one of ...

had argued that the group C₂H₅ constituted a "radical" (a cluster of atoms that did not undergo changes during chemical reactions). (See: Justus Liebig (1834
"Ueber die Constitution des Aethers und seiner Verbindungen"
(On the composition of ethers and their compounds), ''Annalen der Pharmacie'', 9 : 1–39.) In reporting on Liebig's findings (and related work by others), Berzelius coined the names "methyl" and "ethyl" for the "radicals" CH₃ and C₂H₅, respectively. From Jacob Berzelius, ''Årsberättelsen om framsteg i fysik och kemi'' nnual report on progress in physics and chemistry(Stockholm, Sweden: P.A. Norstedt & Söner, 1835)
p. 376
''"Man får då ge namn åt etherradikalerna; man kan kalla den äldre C₄H₁₀, ''ethyl'', den nyare C₂H₆, ''methyl'', … "'' (One may then give names to ether radicals; one can call the older neC₄H₁₀, ''ethyl'', the newer neC₂H₆, ''methyl'', … ote: At that time, chemists used the wrong atomic masses (e.g., 6 for carbon instead of 12); hence the coefficients shown here must be divided by two. In his translation into German of Berzelius' report, the German chemist

Friedrich Wöhler Friedrich Wöhler Royal Society of London, FRS(For) HonFRSE (; 31 July 180023 September 1882) was a German chemist known for his work in both organic chemistry, organic and inorganic chemistry, being the first to isolate the chemical elements be ...

transliterated "ethyl" as "Aethyl". (See: Jöns Jacob Berzelius with Friedrich Wöhler, trans., ''Jahresbericht über die Fortschritte der physischen Wissenschaften'' (Annual report on the progress of the physical sciences), 15 :
381.

References

{{Functional group Alkyl groups *

Ethylation

Stereochemistry

Etymology

See also

References