What is "dinitrogen pentoxide"

n. (context inorganic compound English) The unstable binary compound N₂O₅; a strong oxidizing agent.

Dinitrogen pentoxide is the chemical compound with the formula NO. Also known as nitrogen pentoxide, NO is one of the binary nitrogen oxides, a family of compounds that only contain nitrogen and oxygen. It is an unstable and potentially dangerous oxidizer that once was used as a reagent when dissolved in chloroform for nitrations but has largely been superseded by NOBF ( nitronium tetrafluoroborate).

NO is a rare example of a compound that adopts two structures depending on the conditions: most commonly it is a salt, but under some conditions it is a polar molecule: