Phosphorus dioxide (PO2) is a gaseous oxide of phosphorus.

It is a free radical that plays a role in the chemiluminescence of phosphorus and phosphine.

[1] It is produced when phosphates are heated to high temperatures.

[2] In the ground state the molecule is bent, like nitrogen dioxide, but there is an excited state that is linear.

[1] This inorganic compound–related article is a stub.