betaines 

https://doi.org/10.1351/goldbook.B00637
Originally, the compound betaine,
(CH3)3N+–CH2C(=O)O−
N,N,N-trimethylammonioacetate, and similar zwitterionic compounds derived from other amino acids. By extension, neutral molecules having charge-separated forms with an onium atom which bears no hydrogen atoms and that is not adjacent to the anionic atom. Betaines cannot be represented without formal charges. E.g.
See also: dipolar compounds, mesoionic compounds, ylides, zwitterionic compounds
Source:
PAC, 1995, 67, 1307. (Glossary of class names of organic compounds and reactivity intermediates based on structure (IUPAC Recommendations 1995)) on page 1322 [Terms] [Paper]
Citation: 'betaines' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. https://doi.org/10.1351/goldbook.B00637 RIS BibTex EndNote
Div. IIIPDFTextXMLJSON
Last revised: February 24, 2014