https://doi.org/10.1351/goldbook.B00637
Originally, the compound betaine,
N,N,N-trimethylammonioacetate, and similar zwitterionic compounds derived from other amino acids. By extension, neutral molecules having charge-separated forms with an @O04291@ atom which bears no hydrogen atoms and that is not adjacent to the anionic atom. Betaines cannot be represented without formal charges. E.g. B00637-2.png
B00637-3.png
See also:
dipolar compounds
, mesoionic compounds
, ylides
, zwitterionic compounds