Tetramethylammonium chloride

Tetramethylammonium chloride is one of the simplest quaternary ammonium salts, with four methyl groups tetrahedrally attached to the central N. The chemical formula (CH₃)₄N⁺Cl⁻ is often abbreviated further as Me₄N⁺Cl⁻. It is a hygroscopic colourless solid that is soluble in water and polar organic solvents. Tetramethylammonium chloride is a major industrial chemical, being used widely as a chemical reagent and also as a low-residue bactericide in such processes as hydrofracking. In the laboratory, it has fewer synthetic chemical applications than quaternary ammonium salts containing longer N-alkyl substituents, which are used extensively as phase-transfer catalysts.