Cis-trans isomerism is exhibited by:

Options

A. `[PtCl(NH_(3))_(3)]^(+)`
B. `[Pt(NH_(3))_(4)]^(2+)`
C. `[PtCl_(4)]^(2-)`
D. `[PtCl_(2)(NH_(3))_(2)]`

Answer

To determine which of the given complexes exhibit cis-trans isomerism, we need to analyze each complex based on the type of ligands and their arrangement around the central metal atom.

### Step-by-Step Solution:

1. **Identify the Complexes**: The complexes given are:
- (i) PtCl(NH3)3
- (ii) Pt(NH3)4^2+
- (iii) PtCl4^2-
- (iv) PtCl2(NH3)2

2. **Determine the Type of Each Complex**:
- (i) **PtCl(NH3)3**: This is a MA4 type complex (one metal, one type of ligand (Cl) and three of another type (NH3)). It cannot exhibit cis-trans isomerism since it has only one type of ligand.
- (ii) **Pt(NH3)4^2+**: This is also a MA4 type complex with only one type of ligand (NH3). It cannot exhibit cis-trans isomerism.
- (iii) **PtCl4^2-**: This is a MA4 type complex with only one type of ligand (Cl). It cannot exhibit cis-trans isomerism.
- (iv) **PtCl2(NH3)2**: This is a MA2B2 type complex (two Cl and two NH3 ligands). This complex can exhibit cis-trans isomerism because it has two different types of ligands.

3. **Analyze the MA2B2 Complex**:
- For the complex PtCl2(NH3)2, we can arrange the ligands in two ways:
- **Cis Isomer**: Both Cl ligands are adjacent to each other, while the NH3 ligands are also adjacent.
- **Trans Isomer**: The Cl ligands are opposite each other, and the NH3 ligands are also opposite each other.

4. **Conclusion**: Among the given complexes, only **PtCl2(NH3)2** exhibits cis-trans isomerism.

### Final Answer:
The complex that exhibits cis-trans isomerism is **PtCl2(NH3)2**.

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