Paradoxes and paradigms: on ambisaline ions of nitrogen

Ambisaline ions can be defined as species that exist as cations and as anions in appropriate salts although admittedly not necessarily with well-known or commonly existing counterions. In the present paper we review ambisaline ions of nitrogen as present in solid state salts and add a brief thermochemical commentary. We open our discussion with all nitrogen species composed of solely nitrogen and extend it to polynitrogen ambisaline species consisting of nitrogen(s) with hydrogen (or other univalent groups) affixed to these nitrogens.