Question

What is an ionization isomer?

Answer 1

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 `"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 `"-1/2"` charge with the cobalt.)