Question

The complex ions [Co(NH$_3$)$_5$(NO$_2$)]$^{2+}$ and [Co(NH$_3$)$_5$(ONO)]$^{2+}$ are called

• A. Ionization isomers
• B. Linkage isomers
• C. Co-ordination isomers
• D. Geometrical isomers

Hint:

Linkage isomerism occurs when a ligand can coordinate to the metal ion in more than one way. This is common with nitrito ligands (NO$_2$).

Answer 1

The Correct Option is B

The complex ions [Co(NH$_3$)$_5$(NO$_2$)]$^{2+}$ and [Co(NH$_3$)$_5$(ONO)]$^{2+}$ are linkage isomers.
This occurs because the nitrite (NO$_2$) ligand can coordinate to the cobalt ion through either nitrogen or oxygen, forming different isomers.
Ionization isomerism occurs when the ionization products differ, while coordination isomerism refers to different arrangements of ligands around the metal.