Oxoammonium cations are isoelectronic with carbonyls and structurally related to aldoximes (hydroxylamines), and aminoxyl (nitroxide) radicals, with which they can interconvert via a series of redox steps. According to X-ray crystallography, the N–O distance in [TEMPO]BF is 1.184 Å, 0.1 Å shorter than the N–O distance of 1.284 Å in the charge-neutral TEMPO.  Similarly, the N in [TEMPO] is nearly planar, but the O moves 0.1765 Å out of the plane in the neutral TEMPO.
The N-oxoammonium salts are used for oxidation of alcohols to carbonyl groups, as well as other forms of oxoammonium-catalyzed oxidations. The nitroxyl TEMPO reacts via its N-oxoammonium salt.