The compound (s) the exhibit(s) geometrical isomerism is (are ) :

Options

A. `[Pt(en)Cl_(2)]`
B. `[Pt(en)_(2)]Cl_(2)`
C. `[Pt(en)_(2)Cl_(2)]Cl_(2)`
D. `[Pt(NH_(3))_(2)Cl_(2)]`

Answer

To determine which compounds exhibit geometrical isomerism, we need to analyze each compound's structure and the arrangement of ligands around the central metal atom. Geometrical isomerism typically occurs in coordination compounds where ligands can be arranged in different spatial orientations, leading to cis and trans forms.

### Step-by-Step Solution:

1. **Understanding Geometrical Isomerism**:
- Geometrical isomerism occurs when ligands can be arranged in different spatial orientations around a central atom, leading to distinct isomers.
- The two common forms are cis (where similar ligands are adjacent) and trans (where similar ligands are opposite).

2. **Analyzing the First Compound: Pt(en)(Cl)₂**:
- In this compound, ethylenediamine (en) is a bidentate ligand, meaning it binds through two sites.
- Since en occupies two coordination sites, the two Cl ligands cannot be arranged in a way that allows for cis or trans configurations.
- **Conclusion**: This compound does not exhibit geometrical isomerism.

3. **Analyzing the Second Compound: Pt(en)₂**:
- Here, we have two bidentate en ligands.
- The arrangement is square planar, and both en ligands will occupy opposite positions.
- **Conclusion**: This compound does not exhibit geometrical isomerism.

4. **Analyzing the Third Compound: Pt(en)₂Cl₂**:
- In this case, we have two bidentate en ligands and two Cl ligands.
- The Cl ligands can be arranged opposite each other, while the en ligands can also be opposite or adjacent.
- This allows for both cis (where Cl ligands are adjacent) and trans (where Cl ligands are opposite) configurations.
- **Conclusion**: This compound exhibits geometrical isomerism.

5. **Analyzing the Fourth Compound: Pt(NH₃)₂Cl₂**:
- This compound has two NH₃ ligands and two Cl ligands.
- Similar to the previous case, the NH₃ and Cl ligands can be arranged in a square planar structure.
- The NH₃ ligands can be opposite each other (trans) or adjacent (cis).
- **Conclusion**: This compound also exhibits geometrical isomerism.

### Final Answer:
The compounds that exhibit geometrical isomerism are **Pt(en)₂Cl₂** and **Pt(NH₃)₂Cl₂**.