Triethylamine is the

chemical compound A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one element ...

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 ...

N(CH₂CH₃)₃, commonly abbreviated Et₃N. Like triethanolamine and the

tetraethylammonium Tetraethylammonium (TEA) is a quaternary ammonium cation with the chemical formula , consisting of four ethyl groups (, denoted Et) attached to a central nitrogen atom. It is a counterion used in the research laboratory to prepare lipophilic salt ...

ion, it is often abbreviated TEA. It is a colourless volatile liquid with a strong fishy odor reminiscent of

ammonia Ammonia is an inorganic chemical compound of nitrogen and hydrogen with the chemical formula, formula . A Binary compounds of hydrogen, stable binary hydride and the simplest pnictogen hydride, ammonia is a colourless gas with a distinctive pu ...

. Like diisopropylethylamine (Hünig's base), triethylamine is commonly employed in

organic synthesis Organic synthesis is a branch of chemical synthesis concerned with the construction of organic compounds. Organic compounds are molecules consisting of combinations of covalently-linked hydrogen, carbon, oxygen, and nitrogen atoms. Within the gen ...

, usually as a base.

Synthesis and properties

Triethylamine is prepared by the

alkylation Alkylation is a chemical reaction that entails transfer of an alkyl group. The alkyl group may be transferred as an alkyl carbocation, a free radical, a carbanion, or a carbene (or their equivalents). Alkylating agents are reagents for effecting al ...

of ammonia with

ethanol Ethanol (also called ethyl alcohol, grain alcohol, drinking alcohol, or simply alcohol) is an organic compound with the chemical formula . It is an Alcohol (chemistry), alcohol, with its formula also written as , or EtOH, where Et is the ps ...

: :NH₃ + 3 C₂H₅OH → N(C₂H₅)₃ + 3 H₂O The pK_a of protonated triethylamine is 10.75,David Evans Research Group
and it can be used to prepare buffer solutions at that pH. The hydrochloride

salt In common usage, salt is a mineral composed primarily of sodium chloride (NaCl). When used in food, especially in granulated form, it is more formally called table salt. In the form of a natural crystalline mineral, salt is also known as r ...

, triethylamine hydrochloride (triethylammonium chloride), is a colorless, odorless, and

hygroscopic Hygroscopy is the phenomenon of attracting and holding water molecules via either absorption (chemistry), absorption or adsorption from the surrounding Natural environment, environment, which is usually at normal or room temperature. If water mol ...

powder, which decomposes when heated to 261 °C. Triethylamine is soluble in water to the extent of 112.4 g/L at 20 °C. It is also miscible in common organic solvents, such as acetone, ethanol, and diethyl ether. Laboratory samples of triethylamine can be purified by distilling from calcium hydride. In alkane solvents triethylamine is a Lewis base that forms adducts with a variety of Lewis acids, such as I₂ and

phenols In organic chemistry, phenols, sometimes called phenolics, are a class of chemical compounds consisting of one or more hydroxyl groups (− O H) bonded directly to an aromatic hydrocarbon group. The simplest is phenol, . Phenolic compounds ar ...

. Owing to its steric bulk, it forms complexes with transition metals reluctantly.

Applications

Triethylamine is commonly employed in organic synthesis as a base. For example, it is commonly used as a base during the preparation of

ester In chemistry, an ester is a compound derived from an acid (either organic or inorganic) in which the hydrogen atom (H) of at least one acidic hydroxyl group () of that acid is replaced by an organyl group (R). These compounds contain a distin ...

s and

amide In organic chemistry, an amide, also known as an organic amide or a carboxamide, is a chemical compound, compound with the general formula , where R, R', and R″ represent any group, typically organyl functional group, groups or hydrogen at ...

s from acyl chlorides. Such reactions lead to the production of

hydrogen chloride The Chemical compound, compound hydrogen chloride has the chemical formula and as such is a hydrogen halide. At room temperature, it is a colorless gas, which forms white fumes of hydrochloric acid upon contact with atmospheric water vapor. Hyd ...

which combines with triethylamine to form the salt triethylamine hydrochloride, commonly called triethylammonium chloride. (R, R' =

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 ...

, aryl): :R₂NH + R'C(O)Cl + Et₃N → R'C(O)NR₂ + Et₃NH⁺Cl⁻ Like other tertiary amines, it catalyzes the formation of urethane foams and epoxy resins. It is also useful in dehydrohalogenation reactions and Swern oxidations. Triethylamine is readily alkylated to give the corresponding quaternary ammonium salt: :RI + Et₃N → Et₃NR⁺I⁻ Triethylamine is mainly used in the production of quaternary ammonium compounds for textile auxiliaries and quaternary ammonium salts of dyes. It is also a catalyst and acid neutralizer for

condensation reaction In organic chemistry, a condensation reaction is a type of chemical reaction in which two molecules are combined to form a single molecule, usually with the loss of a small molecule such as water. If water is lost, the reaction is also known as a ...

s and is useful as an intermediate for manufacturing medicines,

pesticide Pesticides are substances that are used to control pests. They include herbicides, insecticides, nematicides, fungicides, and many others (see table). The most common of these are herbicides, which account for approximately 50% of all p ...

s and other chemicals. Triethylamine salts, like any other tertiary ammonium salts, are used as an ion-interaction reagent in ion interaction chromatography, due to their amphiphilic properties. Unlike quaternary ammonium salts, tertiary ammonium salts are much more volatile, therefore

mass spectrometry Mass spectrometry (MS) is an analytical technique that is used to measure the mass-to-charge ratio of ions. The results are presented as a ''mass spectrum'', a plot of intensity as a function of the mass-to-charge ratio. Mass spectrometry is used ...

can be used while performing analysis.

Niche uses

Triethylamine is commonly used in the production of anionic Polyurethane dispersions (resins dispersed in water rather than solvents) as a neutralizing agent. Triethylamine is used to give salts of various carboxylic acid-containing pesticides, e.g. Triclopyr and 2,4-dichlorophenoxyacetic acid. Triethylamine is the active ingredient in FlyNap, a product for anesthetizing fruit flies. It is also used in mosquito and vector control labs to anesthetize mosquitoes. This is done to preserve any viral material that might be present during species identification. The

bicarbonate In inorganic chemistry, bicarbonate (IUPAC-recommended nomenclature: hydrogencarbonate) is an intermediate form in the deprotonation of carbonic acid. It is a polyatomic anion with the chemical formula . Bicarbonate serves a crucial bioche ...

of triethylamine (often abbreviated TEAB, triethylammonium bicarbonate) is useful in reverse phase chromatography, often in a gradient to purify nucleotides and other biomolecules. Triethylamine was discovered by the Germans during the early 1940s to be hypergolic in combination with nitric acid, and was used as a component in the German Wasserfall rocket. The Soviet Scud missile used TG-02, a mixture of 50% xylidine and 50% triethylamine as a starting fluid to ignite its rocket engine.

Natural occurrence

Hawthorn flowers have a heavy, complicated scent, the distinctive part of which is triethylamine, which is also one of the first chemicals produced by a dead human body when it begins to decay. Due to the scent, it is considered unlucky in

British culture The culture of the United Kingdom is influenced by its History of the United Kingdom, combined nations' history, its interaction with the cultures of Europe, the individual diverse cultures of England, Wales, Scotland and Northern Ireland, and ...

to bring hawthorn into a house. Gangrene and

semen Semen, also known as seminal fluid, is a bodily fluid that contains spermatozoon, spermatozoa which is secreted by the male gonads (sexual glands) and other sexual organs of male or hermaphrodite, hermaphroditic animals. In humans and placen ...

are also said to possess a similar odour.The book of general ignorance. John Lloyd & John Mitchinson. Faber & Faber 2006
The Hawthorn
BBC

References

External links