Ammonium Salts
Ammonium Salts
Ammonium salts are ionic compounds with the formula (R)4N+A-, where R is hydrogen, alkyl or aryl groups and A is an anion. When R is alkyl or aryl then they are referred to as quaternary ammonium salts. The quaternary ammonium cations are permanently charged, independent of the pH of their solution. Most of the ammonium salts are soluble in water and strongly dissociated. Ammonium salts are used as cleansing agents, food additives, diuretic, surfactants, antistatic agents and disinfectants. They are known to have antimicrobial activity. Osmotic pressure in cells is stabilized by quaternary ammonium salts.
Quaternary ammonium compounds containing long alkyl chains, like benzalkonium chloride, cetylpyridinium chloride, dofanium chloride, benzethonium chloride, methylbenzethonium chloride, cetalkonium chloride and didecyldimethylammonium chloride have activity against microbes, fungi, amoeba, and certain viruses. Since these quaternary ammonium compounds are deactivated by anionic detergents, they should not be used in hard water. They are routinely used as sanitizing agents. One of the day-to-day applications of quaternary ammonium salts in organic synthesis is their popular application as phase transfer catalysts (PTCs) in catalyzing the reaction between ionic and organic reactants. Chlormequat chloride functions as a plant growth regulator through inhibition of the production of gibberellins.
