Question

The complexes [Co(NH₃)₅NO₂]Cl₂ and [Co(NH₃)₅ONO]Cl₂ are

• A. coordination isomers
• B. geometrical isomers
• C. solvate isomers
• D. ionization isomers
• E. linkage isomers

Answer 1

Answer: (E)

Linkage isomerism arises when a ligand can bind to the metal center through two different atoms. In this case, the two complexes given involve a nitrito ligand, which can bind to the metal center either through the nitrogen (as in \(NO_{2}^–\)) or the oxygen (as in \(ONO–\)), thus creating linkage isomerism. These isomers differ in the donor atom of the ligand.
Therefore, the correct classification for the complexes \([Co(NH_{3})_{5}NO_{2})Cl_{2}]\) and \([Co{(NH_{3})}_{5}ONO)]Cl_{2}\) is linkage isomers.

The correct option is (E) : linkage isomers

Answer 2

The complexes [Co(NH₃)₅NO₂]Cl₂ and [Co(NH₃)₅ONO]Cl₂ are 

linkage isomers

Explanation:

Linkage isomerism occurs when a ligand can coordinate to the metal ion through two different atoms, resulting in distinct isomers. In this case, the ligands involved are nitrite (NO₂) and nitrito (ONO). Both of these ligands can bind to the cobalt metal center, but the point of attachment differs:

• In [Co(NH₃)₅NO₂]Cl₂, the nitrite (NO₂) binds through the nitrogen atom.
• In [Co(NH₃)₅ONO]Cl₂, the nitrito (ONO) binds through the oxygen atom.

This difference in the coordination site of the same ligand leads to the formation of linkage isomers.