# Structure of Br3O8

What is the structure of $\ce{Br3O8}$? It has an odd number of electrons; does that make it a free radical?

The structure given in my book shows

Where did the 7th electron of the central atom go?

Picture from book (Pg 265, NCERT Chemistry Part II, class 11):

The electron didn't go anywhere. It's in an unhybridized p orbital on the central bromine, and yes, $\ce{Br3O8}$ is a free radical. That is why it decomposes above -80ºC.$^{[1]}$
$^{[1]}$ Cotton, F. A. Progress in Inorganic Chemistry - Volume 2; Interscience Publishers: New York, NY, 1960.