Which of the following compounds exhibits linkage isomerism?

Options

A. `[Co(en)_(3)]Cl_(3)`
B. `[Co(NH_(3))_(6)] [Cr(en)_(3)]`
C. `[Co(en)_(2)(NO_(2))Cl]Br`
D. `[Co(NH_(3))_(5)Cl]Br_(2)`

Explanation

To determine which of the given compounds exhibits linkage isomerism, we need to understand what linkage isomerism is and analyze each option provided.

### Step-by-Step Solution:

1. **Understanding Linkage Isomerism**:
- Linkage isomerism occurs when a coordination compound has the same composition but different connectivity between the metal and the ligands. This typically happens when a ligand can coordinate to the metal through different atoms.

2. **Analyzing the Options**:
- We need to evaluate each option to see if any ligand can bond to the metal through different atoms.

3. **Option 1: Cobalt(III) triethylenediamine chloride**:
- Ethylenediamine (en) is a bidentate ligand that coordinates through its nitrogen atoms only. Therefore, there is no possibility for different connectivity.
- **Conclusion**: This compound cannot exhibit linkage isomerism.

4. **Option 2: Cobalt(III) with NH3 and ethylenediamine**:
- Similar to the first option, ethylenediamine coordinates through nitrogen atoms. The presence of NH3 does not provide an alternative bonding site for linkage isomerism.
- **Conclusion**: This compound cannot exhibit linkage isomerism.

5. **Option 3: Cobalt(III) with NH3, chloride, and bromide**:
- In this case, NH3 can only bond through nitrogen, and both chloride and bromide are monodentate ligands that bond through their respective halogen atoms. There is no alternative bonding site for linkage isomerism.
- **Conclusion**: This compound cannot exhibit linkage isomerism.

6. **Option 4: Cobalt(III) with NH3 and thiocyanate (SCN-)**:
- Thiocyanate can coordinate to the metal through either the sulfur atom (thiocyanato) or the nitrogen atom (isothiocyanato). This provides two different connectivity options for the same ligand.
- **Conclusion**: This compound can exhibit linkage isomerism.

### Final Answer:
The compound that exhibits linkage isomerism is **Option 4: Cobalt(III) with NH3 and thiocyanate (SCN-)**.