Amide (functional group)
In chemistry, the term amide ({{IPAc-en|ˈ|æ|m|aɪ|d}} or {{IPAc-en|ˈ|æ|m|ɪ|d}} or {{IPAc-en|ˈ|eɪ|m|aɪ|d}}){{cite web|url=http://www.collinsdictionary.com/dictionary/english/amide|title=Amide definition and meaning - Collins English Dictionary|website=www.collinsdictionary.com|access-date=15 April 2018}}{{Cite American Heritage Dictionary|amide}}{{cite web|url=http://www.oxforddictionaries.com/us/definition/english/amide|archive-url=https://web.archive.org/web/20150402184403/http://www.oxforddictionaries.com/us/definition/english/amide|url-status=dead|archive-date=April 2, 2015|title=amide - Definition of amide in English by Oxford Dictionaries|website=Oxford Dictionaries - English|access-date=15 April 2018}} is a compound with the functional group RnE(=O)xNR2, where x is not zero, E is some element, and each R represents an organic group or hydrogen.{{goldbookref|file=A00266|title=amides}} It is a derivative of an oxoacid RnE(=O)xOH with an hydroxy group –OH replaced by an amine group –NR2.
Some important subclasses are
- carboxamides, or organic amides, where E = carbon, with the general formula RC(=O)NR2.
- phosphoramides, where E = phosphorus, such as R2P(=O)NR2
- sulfonamides, where E = sulfur, namely RS(=O)2NR2
The term amide may also refer to
- amide group, a functional group –C(=O)N= consisting of a carbonyl adjacent to a nitrogen atom.
- cyclic amide or lactam, a cyclic compound with the amide group –C(=O)N– in the ring.
- metal amide, an ionic compound ("salt") with the azanide anion H2N− (the conjugate base of ammonia) or to a derivative thereof R2N−.
There is also a neutral amino radical (•NH2) and a positively charged NH2+ ion called a nitrenium ion, but both of these are very unstable.