Quaternary ammonium cation

Quaternary ammonium cation. The R groups may be the same or different alkyl or aryl groups. Also, the R groups may be connected.

In organic chemistry, quaternary ammonium cations, also known as quats, are positively-charged polyatomic ions of the structure [NR4]+, where R is an alkyl group, an aryl group[1] or organyl group. Unlike the ammonium ion (NH+4) and the primary, secondary, or tertiary ammonium cations, the quaternary ammonium cations are permanently charged, independent of the pH of their solution. Quaternary ammonium salts or quaternary ammonium compounds (called quaternary amines in oilfield parlance) are salts of quaternary ammonium cations. Polyquats are a variety of engineered polymer forms which provide multiple quat molecules within a larger molecule.

Quats are used in consumer applications including as antimicrobials (such as detergents and disinfectants), fabric softeners, and hair conditioners. As an antimicrobial, they are able to inactivate enveloped viruses (such as SARS-CoV-2). Quats tend to be gentler on surfaces than bleach-based disinfectants, and are generally fabric-safe.[2]

"Top" view of Bu4N+ as determined by X-ray crystallography.[3]
"Side" view of Bu4N+ as determined by X-ray crystallography.[3]
  1. ^ IUPAC, Compendium of Chemical Terminology, 2nd ed. (the "Gold Book") (1997). Online corrected version: (2006–) "quaternary ammonium compounds". doi:10.1351/goldbook.Q05003
  2. ^ Heffernan T (14 April 2021). "The Best Surface Cleaners, Wipes, and Disinfectants". The New York Times. ISSN 0362-4331. Retrieved 2022-02-17.
  3. ^ a b Kern A, Näther C, Studt F, Tuczek F (August 2004). "Application of a universal force field to mixed Fe/Mo-S/Se cubane and heterocubane clusters. 1. Substitution of sulfur by selenium in the series [Fe4X4(YCH3)4]2-; X = S/Se and Y = S/Se". Inorganic Chemistry. 43 (16): 5003–5010. doi:10.1021/ic030347d. PMID 15285677.