The complexes `[Co(NH_3)_4(H_2O)Cl] Br_2 and [Co(NH_3)_4Br_2]Cl.H_2O` are examples of

Options

A. ionization isomerism
B. linkage isomerism
C. geometrical isomerism
D. optical isomerism

Answer

To determine the type of isomerism exhibited by the complexes \([Co(NH_3)_4(H_2O)Cl] Br_2\) and \([Co(NH_3)_4Br_2]Cl.H_2O\), we can analyze their structures and the nature of their ligands.

### Step-by-Step Solution:

1. **Identify the Complexes**:
- The first complex is \([Co(NH_3)_4(H_2O)Cl] Br_2\).
- The second complex is \([Co(NH_3)_4Br_2]Cl.H_2O\).

2. **Examine the Ligands**:
- Both complexes contain the same ligands: \(NH_3\), \(H_2O\), \(Cl\), and \(Br\).
- The ligands are arranged differently in each complex.

3. **Coordination Sphere Analysis**:
- In the first complex, \(H_2O\) and \(Cl\) are part of the coordination sphere (inside), while \(Br_2\) is outside.
- In the second complex, \(Br_2\) is now part of the coordination sphere, and \(Cl\) is outside.

4. **Identify the Type of Isomerism**:
- Since the position of the ligands has changed (with some ligands moving in and out of the coordination sphere), this indicates a type of isomerism where the same ligands can yield different ions in solution.
- This is characteristic of **ionization isomerism**, where the complexes yield different ions when dissolved in a solvent.

5. **Conclusion**:
- The two complexes \([Co(NH_3)_4(H_2O)Cl] Br_2\) and \([Co(NH_3)_4Br_2]Cl.H_2O\) are examples of **ionization isomerism**.