Zwitterion

<p>In <a href="/facts/Chemistry/SrNqkGVm">chemistry</a>, a zwitterion , also called an inner salt or dipolar ion, is a <a href="/facts/Molecule/N9ljSfFq">molecule</a> that contains an equal number of positively and negatively charged <a href="/facts/Functional_group/GXkSPsjM">functional groups</a>.
1,2-<a href="/facts/Dipolar_compound/kIFk8olW">dipolar compounds</a>, such as <a href="/facts/Ylide/WcfsUPR7">ylides</a>, are sometimes excluded from the definition.
</p><p>Some zwitterions, such as <a href="/facts/Amino_acid/WDxYwBny">amino acid</a> zwitterions, are in <a href="/facts/Equilibrium_chemistry/mkjCWwnx">chemical equilibrium</a> with an uncharged "parent" molecule. <a href="/facts/Betaine/3sG11tpp">Betaines</a> are zwitterions that cannot <a href="/facts/Isomerization/sxv23uKl">isomerize</a> to an all-neutral form, such as when the positive charge is located on a <a href="/facts/Quaternary_ammonium/bNpF1goc">quaternary ammonium</a> group. Similarly, a molecule containing a <a href="/facts/Phosphonium/uS2PCt7X">phosphonium</a> group and a <a href="/facts/Carboxylate/vEDekXRr">carboxylate</a> group cannot isomerize.
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Zwitterion open-in-new

Zwitterion