Dinitrogen pentoxide

Dinitrogen pentoxide (also known as nitrogen pentoxide or nitric anhydride) is the chemical compound with the formulaN₂O₅. It is one of the binary nitrogen oxides, a family of compounds that contain only nitrogen and oxygen. It exists as colourless crystals that sublime slightly above room temperature, yielding a colorless gas.

Dinitrogen pentoxide has been used for nitrations but has largely been superseded by nitronium tetrafluoroborate (NO₂BF₄).