# What is an ionization isomer?

Nov 19, 2015

We see these in transition metal complexes. Take the following compound for example:

["CoBr"("NH"_3)_5]"SO"_4

This is called pentaamminebromocobalt sulfate.

["CoSO"_4("NH"_3)_5]"Br"

This is called pentaamminesulfatocobalt bromide.

In either case, the cobalt is $\text{Co(III)}$, and none of the ammonia molecules contribute to the charge. The charges also all cancel out nicely.

(Sulfate is a resonance hybrid structure in real life, and each oxygen shares a $\text{-1/2}$ charge with the cobalt.)