Question

\([\text{Co}(NH_3)_4Cl_2]NO_2\) and \([\text{Co}(NH_3)_4ClNO_2]Cl\) exhibit which type of isomerism?

• A. Geometrical
• B. Optical
• C. Linkage
• D. Ionisation

Hint:

If ligand inside coordination sphere and counter ion outside swap their positions, the isomerism is ionisation isomerism.

Answer 1

The Correct Option is D

Step 1: Understand ionisation isomerism.
Ionisation isomerism occurs when a counter ion and a ligand exchange their positions between coordination sphere and ionisable part.
Step 2: Analyze the two given complexes.
\[ [\text{Co}(NH_3)_4Cl_2]NO_2 \] Here \(NO_2^-\) is outside coordination sphere (counter ion).
\[ [\text{Co}(NH_3)_4ClNO_2]Cl \] Here \(NO_2^-\) is inside coordination sphere and \(Cl^-\) is outside.
Step 3: Exchange of ions.
Since \(NO_2^-\) and \(Cl^-\) exchange positions, this is ionisation isomerism.
Final Answer: \[ \boxed{\text{Ionisation isomerism}} \]