Triethylamine is the chemical compound with the formula N(CH2CH3)3, commonly abbreviated Et3N. It is also abbreviated TEA, yet this abbreviation must be used carefully to avoid confusion with triethanolamine or tetraethylammonium, for which TEA is also a common abbreviation. It is a colourless volatile liquid with a strong fishy odor reminiscent of ammonia. Like diisopropylethylamine (Hünig's base), triethylamine is commonly employed, usually as a base, in organic synthesis.
|Preferred IUPAC name
Triethylamine (no longer IUPAC name)
3D model (JSmol)
CompTox Dashboard (EPA)
|Molar mass||101.193 g·mol−1|
|Density||0.7255 g mL−1|
|Melting point||−114.70 °C; −174.46 °F; 158.45 K|
|Boiling point||88.6 to 89.8 °C; 191.4 to 193.5 °F; 361.7 to 362.9 K|
|Vapor pressure||6.899–8.506 kPa|
|66 μmol Pa−1 kg−1|
|Acidity (pKa)||10.75 (for the conjugate acid) (H2O), 9.00 (DMSO)|
Refractive index (nD)
Heat capacity (C)
|216.43 J K−1 mol−1|
Std enthalpy of
|−169 kJ mol−1|
Std enthalpy of
|−4.37763 to −4.37655 MJ mol−1|
|GHS Signal word||Danger|
|H225, H302, H312, H314, H332|
|P210, P280, P305+351+338, P310|
|NFPA 704 (fire diamond)|
|Flash point||−15 °C (5 °F; 258 K)|
|312 °C (594 °F; 585 K)|
Threshold limit value (TLV)
|2 ppm (8 mg/m3) (TWA), |
4 ppm (17 mg/m3) (STEL)
|Lethal dose or concentration (LD, LC):|
LD50 (median dose)
LCLo (lowest published)
|1425 ppm (mouse, 2 hr)|
|NIOSH (US health exposure limits):|
|TWA 25 ppm (100 mg/m3)|
IDLH (Immediate danger)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Synthesis and propertiesEdit
- NH3 + 3 C2H5OH → N(C2H5)3 + 3 H2O
The pKa of protonated triethylamine is 10.75, and it can be used to prepare buffer solutions at that pH. The hydrochloride salt, triethylamine hydrochloride (triethylammonium chloride), is a colorless, odorless, and hygroscopic 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.
In alkane solvents triethylamine is a Lewis base that forms adducts with a variety of Lewis acid such as I2 and phenols. Owing to its steric bulk, it forms complexes with transition metals reluctantly.
Triethylamine is commonly employed in organic synthesis as a base. For example, it is commonly used as a base during the preparation of esters and amides from acyl chlorides. Such reactions lead to the production of hydrogen chloride which combines with triethylamine to form the salt triethylamine hydrochloride, commonly called triethylammonium chloride. This reaction removes the hydrogen chloride from the reaction mixture, which can be required for these reactions to proceed to completion (R, R' = alkyl, aryl):
- R2NH + R'C(O)Cl + Et3N → R'C(O)NR2 + Et3NH+Cl−
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 reactions and is useful as an intermediate for manufacturing medicines, pesticides 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 can be used while performing analysis.
Triethylamine is the active ingredient in FlyNap, a product for anesthetizing Drosophila melanogaster. Triethylamine is 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.
Also, the bicarbonate salt of triethylamine (often abbreviated TEAB, triethylammonium bicarbonate) is useful in reverse phase chromatography, often in a gradient to purify nucleotides and other biomolecules.
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. For this reason, it is considered as unlucky to bring Hawthorn (or May blossom) into the house. Gangrene is also said to possess a similar odour. On a brighter note, it is also described as 'the smell of sex', specifically of semen.
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