Ionization isomerism is possible with
 

• Ionization isomerism refers to the property of compounds that, despite having the same composition, produce distinct ions in a solution.

$\left[\mathrm{Co}{\left({\mathrm{NH}}_3\right)}_5\mathrm{Cl}\right]\mathrm{Br}$ will give ${\mathrm{Br}}^{-}$ion in solution. Its isomer$\left[\mathrm{Co}{\left({\mathrm{NH}}_3\right)}_5\mathrm{Br}\right]\mathrm{Cl}$ will give ${\mathrm{Cl}}^{-}$ ion in solution.