Tetrabutylammonium chloride
Tetrabutylammonium chloride is the organic compound with the formula, often abbreviated as, where Bu stands for n-butyl. A white water-soluble solid, it is a quaternary ammonium salt of chloride.
It sees use as a phase-transfer catalyst, although it is less popular that the corresponding bromine salt TBAB. It can also undergo salt metathesis reactions to form a variety of other tetrabutylammonium salts. Often tetrabutylammonium bromide is preferred as a source of tetrabutylammonium because it is less hygroscopic than the chloride.