Which of the following compound may be optical active ?

Options

A. `Co(en)_(2)Cl_(2)`
B. `[Rh Cl Br NH_(3) PH_(3)]^(-)`
C. `Cu(en)_(2)Cl_(2)`
D. All of these

Answer

To determine which of the given compounds may be optically active, we need to analyze the structures of each compound and check for the presence of a plane of symmetry. A compound is optically active if it does not possess a plane of symmetry, allowing it to exist in two non-superimposable mirror images (enantiomers).

### Step-by-Step Solution:

1. **Analyze Compound A: [Co(en)₂Cl₂]**
- **Structure Drawing**: Start by drawing the structure of the compound. The central metal ion is cobalt (Co), which is coordinated by two ethylenediamine (en) ligands and two chloride (Cl) ligands.
- **Cis and Trans Forms**: Identify the two possible geometric isomers: cis and trans.
- **Trans Form**: In the trans configuration, the two Cl ligands are opposite each other. This creates a plane of symmetry, indicating that the compound is not optically active.
- **Cis Form**: In the cis configuration, the two Cl ligands are adjacent. This arrangement does not have a plane of symmetry, allowing for optical activity. Therefore, the cis form is optically active.

2. **Analyze Compound B: [RhClBr(NH₃)(Ph₃)]⁻**
- **Structure Drawing**: Draw the structure with Rh as the central atom, coordinated to Cl, Br, NH₃, and Ph₃.
- **Different Ligands**: Since all four ligands are different, there is no plane of symmetry in any configuration (cis or trans). This confirms that the compound is optically active.

3. **Analyze Compound C: [Cu(en)₂Cl₂]**
- **Comparison with Compound A**: The structure is similar to compound A, with copper (Cu) as the central atom instead of cobalt (Co). The coordination environment remains the same.
- **Optical Activity**: Since compound A was found to be optically active in its cis form, compound C will also be optically active for the same reasons.

4. **Final Conclusion**: Since compounds A, B, and C can all exhibit optical activity, the correct answer is that all of the above compounds may be optically active.

### Final Answer:
**D. All of the above.**