Tetramethylammonium Chloride (TMAC) is a quaternary ammonium salt with the chemical formula C₁₂H₃₁ClN. It consists of a central nitrogen atom bonded to four methyl groups and a chloride ion. TMAC is commonly used in laboratories as a reagent and in various chemical syntheses. In addition to its role in research, TMAC is also utilized in the production of surfactants and as a phase transfer catalyst. Its unique structure allows it to facilitate the transfer of ions between different phases in chemical reactions, making it valuable in organic chemistry and industrial applications.