Tetraethylammonium hydroxide

Tetraethylammonium hydroxide is the organic compound with the formula (C₂H₅)₄NOH, abbreviated Et₄NOH. It is the tetraethylammonium salt of hydroxide. It is used and dispensed as solutions in water or alcohols, which are colorless and highly alkaline. The compound is a common reagent in organic synthesis. It is also employed in the preparation of zeolites.^[1]

Tetraethylammonium hydroxide

Names
IUPAC name N,N,N-Triethylethanaminium hydroxide
Identifiers
CAS Number	77-98-5
3D model (JSmol)	Interactive image
ChemSpider	6263
ECHA InfoCard	100.000.977
EC Number	201-073-3
PubChem CID	6509
UNII	RA8VU41B1F
CompTox Dashboard (EPA)	DTXSID30883222
InChI InChI=1S/C8H20N.H2O/c1-5-9(6-2,7-3)8-4;/h5-8H2,1-4H3;1H2/q+1;/p-1 Key: LRGJRHZIDJQFCL-UHFFFAOYSA-M
SMILES CC[N+](CC)(CC)CC.[OH-]
Properties
Chemical formula	C8H21NO
Molar mass	147.262 g·mol−1
Appearance	colorless solutions
Hazards
GHS labelling:
Pictograms
Signal word	Warning
Hazard statements	H314, H410
Precautionary statements	P260, P264, P273, P280, P301+P330+P331, P303+P361+P353, P304+P340, P305+P351+P338, P310, P321, P363, P391, P405, P501
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Structure

Structure of Et₄NOH^.4H₂O.^[2]

Tetraethylammonium hydroxide is most commonly encountered as an aqueous solution. Several hydrates NEt₄OH·xH₂O. have been crystallized, including x = 4, 5, 9. These salts feature well separated Et₄N⁺ cations and hydroxide anions. The hydroxide groups are linked by hydrogen bonds to the water of crystallization. Anhydrous Tetraethylammonium hydroxide has not been isolated.

Synthesis and reactions

It is prepared from tetraethylammonium bromide by salt metathesis, using a hydroxide-loaded ion exchange column or by the action of silver oxide.^[3] Attempted isolation of Et₄NOH induces Hofmann elimination, leading to triethylamine and ethylene.

Treatment of Et₄NOH with a wide range of acids gives water and the other tetraethylammonium salts:

Et₄NOH + HX → Et₄NX + H₂O