Dibromine pentoxide is the chemical compound composed of bromine and oxygen with the formula Br<sub>2</sub>O<sub>5</sub>. It is a colorless solid that is stable below −20 ðC. It has the structure O<sub>2</sub>Br−O−BrO<sub>2</sub>, the Br−O−Br bond is bent with bond angle 121.2ð. Each BrO<sub>3</sub> group is pyramidal with the bromine atom at the apex.
Dibromine pentoxide can be prepared by reacting a solution of bromine in dichloromethane with ozone at low temperatures and recrystallized from propionitrile.