[1] It consists of a central pair of bonded nitrogen atoms with four hydroxyl groups around them, giving rise to hydrazine-1,1,2,2-tetrol as an alternate chemical name.
The corresponding anion called nitroxylate is N2O4−4; its empirical formula NO2−2 is the basis for the original names of some of its salts.
The first clue that nitroxylic acid exists was when Edward Bedford Maxted electrolysed sodium nitrite dissolved in liquid ammonia.
The substance is called sodium nitroxylate by current systematic nomenclature rules.
Disodium nitrite is very unstable and experimenters often had their apparatus destroyed when making it.