Chemistry:Quaternary compound
In chemistry, a quaternary compound is a compound consisting of exactly four chemical elements.
In another use of the term in organic chemistry, a quaternary compound is or has a cation consisting of a central positively charged atom with four substituents, especially organic (alkyl and aryl) groups, discounting hydrogen atoms.[1]
The best-known quaternary compounds are quaternary ammonium salts, having a nitrogen atom at the centre.[2] For example, in the following reaction, the nitrogen atom is said to be quaternized as it has gone from 3 to 4 substituents:
- [math]\ce{ R3N + RCl -> R4N+Cl- }[/math]
Other examples include substituted phosphonium salts (R
4P+
), substituted arsonium salts (R
4As+
) like arsenobetaine, as well as some arsenic-containing superconductors.[3] Substituted stibonium (R
4Sb+
)[4] and bismuthonium salts (R
4Bi+
) have also been described.[5]
See also
- Binary compound
- Ternary compound
- Onium ion
- Quaternary phase
References
- ↑ IUPAC, Compendium of Chemical Terminology, 2nd ed. (the "Gold Book") (1997). Online corrected version: (2006–) "Onium compounds". doi:10.1351/goldbook.O04291
- ↑ IUPAC, Compendium of Chemical Terminology, 2nd ed. (the "Gold Book") (1997). Online corrected version: (2006–) "Quaternary ammonium compounds". doi:10.1351/goldbook.Q05003
- ↑ Ren, Z. A.; Yang, J.; Lu, W.; Yi, W.; Shen, X. L.; Li, Z. C.; Che, G. C.; Dong, X. L. et al. (2008). "Superconductivity in the iron-based F-doped layered quaternary compound Nd[O1 − x Fx]FeAs". EPL 82 (5): 57002. doi:10.1209/0295-5075/82/57002. Bibcode: 2008EL.....8257002R.
- ↑ Widler, H. -J.; Schwarz, W.; Hausen, H. -D.; Weidlein, J. (1977). "Tetramethyl-Arsonium- und -Stibonium-Methylchlorometallate des Galliums und Indiums". Zeitschrift für anorganische und allgemeine Chemie 435: 179–190. doi:10.1002/zaac.19774350124.
- ↑ Nicholas C. Norman (1997). Chemistry of arsenic, antimony, and bismuth. Springer Netherlands. p. 316. ISBN 0-7514-0389-X. https://books.google.com/books?id=vVhpurkfeN4C&q=tetramethyl+bismuthonium&pg=PA316.
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