Tetraethylammonium iodide
# Tetraethylammonium iodide

Tetraethylammonium iodide is a quaternary ammonium compound with the chemical formula $C_8H_{20}N^+I^−.$ It has been used as the source of tetraethylammonium ions in pharmacological and physiological studies, but is also used in organic chemical synthesis.

## Chemistry

### Preparation

Tetraethylammonium iodide is commercially available, but can be prepared by the reaction between triethylamine and ethyl iodide.

### Structure

The crystal structure of tetraethylammonium iodide has been determined. The crystal structure is a distorted wurtzite lattice. At the nitrogen atom, the coordination is a flattened tetrahedron. The N−C−C angle is slightly larger than the tetrahedral angle.

### Synthetic applications

Examples include:

* Stereoselective formation of (Z)-diiodoalkenes by treatment of alkynes with ICl in the presence of tetraethylammonium iodide.
* 2-Hydroxyethylation (attachment of $−CH_2−CH_2−OH)$ by ethylene carbonate of carboxylic acids and certain heterocycles bearing an acidic N-H. For example, benzoic acid is converted to the ester, 2-hydroxyethyl benzoate, by treatment with ethylene carbonate in the presence of tetraethylammonium iodide.
* Phase-transfer catalyst in geminal di-alkylation of fluorene, N,N-dialkylation of aniline and N-alkylation of carbazole using aqueous sodium hydroxide and alkyl halides.

## Toxicity

$LD_{50}:$ 35 mg/kg (mouse, i.p.); 56 mg/kg (mouse, i.v.)

