# What is the oxidation state of bromine in BrO3?

I came across this compound $$\ce{BrO3}$$ in my textbook, and was trying to find the oxidation state of bromine.

This is how I proceeded:

• Since this is not a superoxide or a peroxide, or any other case where the oxidation state of oxygen is not −2 according to this, so the oxidation state of oxygen should be −2.
• For oxidation state of Br as $$x$$, I can have $$x + 3(-2) = 0$$, which gives $$x = +6$$.

But, according to Wikipedia, the +6 oxidation state of Br is not listed.

I was confused because my book (NCERT Part I for class XII) says that "The bromine oxides Br2O, BrO2, BrO3 are the least stable halogen oxides (middle row anomaly) and exist only at low temperatures."

Please tell me where I am going wrong.

P. S. This is not an ion $$(\ce{BrO3-})$$ but a neutral compound.

Bretherick’s Handbook of Reactive Chemical Hazards lists bromine trioxide $$\ce{BrO3}$$ structure as the one composed of cationic and anionic parts [1, p. 116]:
The solid produced at $$\pu{—5 °C}$$ by interaction of bromine and ozone is only stable at $$\pu{—80 °C}$$ or in presence of ozone, and decomposition may be violently explosive in presence of trace impurities [...]. The structure may be the dimeric bromyl perbromate, analogous to $$\ce{Cl2O6}$$ [2].
so that formula written as $$\ce{BrO3}$$ is fine being a formula unit, but more correctly bromine trioxide should be written as $$\ce{[BrO2]+[BrO4]-}$$, implying that bromine is in two oxidation states: $$+5$$ and $$+7$$.