Tetraethylammonium bromide

Chemical properties

white to light yellow crystalline solid

The Uses of Tetraethylammonium bromide

Tetraethylammonium Bromide can be used as a source of tetraethylammonium ions for various pharmaceutical studies. It has also the ability to block K+ channels in various tissues.

The Uses of Tetraethylammonium bromide

• Tetraethylammonium bromide (TEAB) catalyzes the synthesis of thioesters by the oxidative coupling of aldehydes or alcohols with thiols or disulfides.
• It is used as a catalyst, along with o-iodoxybenzoic acid (IBX), in the oxidation of sulfides to sulfoxides and primary carboxamides to one-carbon dehomologated nitriles.
• TEAB can also be used as an organic template to synthesize zeolite beta.

Crystal Structure

The crystal structure of Tetraethylammonium bromide has been determined and found to exhibit a distorted tetrahedral symmetry with respect to the geometry of the C atoms around the central N.

Preparation

Tetraethylammonium bromide is commercially available, but can be prepared by the reaction between tetraethylammonium hydroxide and hydrobromic acid:

Et₄N+HO^- + HBr → Et₄N+Br^- + H₂O

Toxicity

The toxicity of tetraethylammonium bromide is primarily due to the tetraethylammonium ion, which has been studied extensively. LD50 for mouse: 38 mg/kg, i.v.; 60 mg/kg, i.p.; >2000 mg/kg, p.o.

General Description

The use of ion-pairing reagents as mobile phase additives allows the separation of ionic and highly polar substances on reversed phase HPLC columns. The purity of mobile phase additives is of utmost importance to their successful application. Sigma-Aldrich offers an outstanding range of tailor-made reagents for anionic (quaternary ammonium and phosphonium salts) and cationic (alkanesulfonates) determination. All mobile phase additives are subject to rigorous testing with special emphasis on the requirements of modern reversed phase HPLC:

Purification Methods

Recrystallise the bromide from EtOH, CHCl3 or diethyl ether, or recrystallise it from acetonitrile and dry it over P2O5 under reduced pressure for several days. It also recrystallises from EtOH/diethyl ether (1:2), EtOAc, water or boiling MeOH/acetone (1:3) or by adding an equal volume of acetone and allowing to cool. Dry it at 100o in vacuo for 12 days, and store over P2O5. [Beilstein 4 IV 332.]