Tetraethylammonium chloride (TEAC) is a

quaternary ammonium compound In organic chemistry, quaternary ammonium cations, also known as quats, are positively-charged polyatomic ions of the structure , where R is an alkyl group, an aryl group or organyl group. Unlike the ammonium, ammonium ion () and the primary, sec ...

with the chemical formula , sometimes written as . In appearance, it is a hygroscopic, colorless, crystalline solid. It has been used as the source of

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 ...

ions in pharmacological and physiological studies, but is also used in organic chemical synthesis.

Preparation and structure

TEAC is produced by alkylation of triethylamine with ethyl chloride. TEAC exists as either of two stable hydrates, the monohydrate and tetrahydrate. The crystal structure of has been determined, as has that of the tetrahydrate, . Details for the preparation of large, prismatic crystals of are given by Harmon and Gabriele, who carried out IR-spectroscopic studies on this and related compounds. These researchers have also pointed out that, although freshly-purified is free of

triethylamine Triethylamine is the chemical compound with the formula N(CH2CH3)3, commonly abbreviated Et3N. Like triethanolamine and the tetraethylammonium ion, it is often abbreviated TEA. It is a colourless volatile liquid with a strong fishy odor remini ...

hydrochloride, small quantities of this compound form on heating of TEAC as the result of a Hofmann elimination: :

Synthetic applications

To a large extent, the synthetic applications of TEAC resemble those of

tetraethylammonium bromide Tetraethylammonium bromide (TEAB) is a quaternary ammonium compound with the chemical formula C8H20N+Br−, often written as "Et4N+Br−" in the chemical literature. It has been used as the source of tetraethylammonium ions in pharmacological and ...

(TEAB) and tetraethylammonium iodide (TEAI), although one of the salts may be more efficacious than another in a particular reaction. For example, TEAC produces better yields than TEAB or TEAI as a co-catalyst in a reaction to prepare diarylureas from arylamines, nitroaromatics and

carbon monoxide Carbon monoxide (chemical formula CO) is a poisonous, flammable gas that is colorless, odorless, tasteless, and slightly less dense than air. Carbon monoxide consists of one carbon atom and one oxygen atom connected by a triple bond. It is the si ...

. In other examples, such as the following, TEAC is not as effective as TEAB or TEAI: * 2-Hydroxyethylation (attachment of ) by

ethylene carbonate Ethylene carbonate (sometimes abbreviated EC) is the organic compound with the formula (CH2O)2CO. It is classified as the cyclic carbonate ester of ethylene glycol and carbonic acid. At room temperature (25 °C) ethylene carbonate is a tra ...

carboxylic acids In organic chemistry, a carboxylic acid is an organic acid that contains a carboxyl group () attached to an Substituent, R-group. The general formula of a carboxylic acid is often written as or , sometimes as with R referring to an organyl ...

and certain heterocycles bearing an acidic N-H. *

Phase-transfer catalyst In chemistry, a phase-transfer catalyst or PTC is a catalyst that facilitates the Phase transition, transition of a reactant from one phase (matter), phase into another phase where reaction occurs. Phase-transfer catalysis is a special form of cat ...

geminal In chemistry, the descriptor geminal () refers to the relationship between two atoms or functional groups that are attached to the same atom. A geminal diol, for example, is a diol (a molecule that has two alcohol functional groups) attached to ...

di-

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 ...

fluorene Fluorene , or 9''H''-fluorene is an organic compound with the formula (C6H4)2CH2. It forms white crystals that exhibit a characteristic, aromatic odor similar to that of naphthalene. Despite its name, it does not contain the element fluorine, but ...

, N,N-dialkylation of

aniline Aniline (From , meaning ' indigo shrub', and ''-ine'' indicating a derived substance) is an organic compound with the formula . Consisting of a phenyl group () attached to an amino group (), aniline is the simplest aromatic amine. It is an in ...

and N-alkylation of

carbazole Carbazole is an aromatic Heterocyclic compound, heterocyclic organic compound. It has a tricyclic structure, consisting of two six-membered benzene rings fused on either side of a five-membered nitrogen-containing ring. The compound's structure is ...

using aqueous

sodium hydroxide Sodium hydroxide, also known as lye and caustic soda, is an inorganic compound with the formula . It is a white solid ionic compound consisting of sodium cations and hydroxide anions . Sodium hydroxide is a highly corrosive base (chemistry), ...

and

alkyl halides The haloalkanes (also known as halogenoalkanes or alkyl halides) are alkanes containing one or more halogen substituents of hydrogen atom. They are a subset of the general class of halocarbons, although the distinction is not often made. Haloalka ...

Biology

In common with

and tetraethylammonium iodide, TEAC has been used as a source of tetraethylammonium ions for numerous clinical and pharmacological studies, which are covered in more detail under the entry for

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 ...

. Briefly, TEAC has been explored clinically for its ganglionic blocking properties, although it is now essentially obsolete as a drug, and it is still used in physiological research for its ability to block channels in various tissues.

Toxicity

The toxicity of TEAC is primarily due to the tetraethylammonium ion, which has been studied extensively. The acute toxicity of TEAC is comparable to that of

and tetraethylammonium iodide. These dataO. M. Gruhzit, R. A. Fisken and B. J. Cooper (1948). "Tetraethylammonium chloride C₂H₅)₄NCl Acute and chronic toxicity in experimental animals". ''J. Pharmacol. Exp. Ther.'' 92 103–107. are provided for comparative purposes; additional details may be found in the entry for

References

{{reflist Tetraethylammonium salts Chlorides

Preparation and structure

Synthetic applications

Biology

Toxicity

See also

References