Tetraethylammonium
Tetraethylammonium (TEA) is a quaternary ammonium cation with the chemical formula [(CH3CH2)4N]+, consisting of four ethyl groups (−CH2CH3 or −C2H5, often abbreviated as −Et) attached to a central nitrogen atom. It is a counterion used in the research laboratory to prepare lipophilic salts of inorganic anions.