Chiral complex from the following is:
Here en = ethylene diamine

Options

A. cis- `[PtCl_(2)(NH_(3))_(2)]`
B. trans- `[PtCl_(2)(en)_(2)]^(2+)`
C. `trans-[Co(NH_(3))_(4)Cl_(2)]^(+)`
D. cis- `[PtCl_(2)(en)_(2)]^(2+)`

Answer

To determine the chiral complex from the given options, we need to analyze the symmetry of each complex. A chiral complex is one that lacks any elements of symmetry, such as a plane of symmetry (POS), axis of symmetry (AOS), or center of symmetry (COS).

### Step-by-Step Solution:

1. **Identify the Complexes**: We are given a complex that involves ethylenediamine (en) as a ligand. The possible complexes could be in the form of PtCl2(en)2 or similar variations.

2. **Draw the Structures**: For each complex, draw the 3D structure to visualize the arrangement of ligands around the central metal atom (in this case, platinum, Pt).

3. **Analyze Symmetry**:
- **Cis Configuration**: For the complex PtCl2(en)2 in a cis configuration, the two ethylenediamine ligands are on the same side. In this case, there is no plane of symmetry because the arrangement of the ligands does not allow for a symmetrical division. Therefore, this complex can be chiral.
- **Trans Configuration**: If the complex were in a trans configuration, the two ethylenediamine ligands would be on opposite sides. This arrangement would create a plane of symmetry, making the complex achiral.
- **Other Complexes**: For other complexes with different ligands, check if they have a plane of symmetry. If they do, they are not chiral.

4. **Conclusion**: After analyzing the structures, the complex that is chiral is the one with the cis arrangement of ethylenediamine ligands, which does not have any plane of symmetry.

### Final Answer:
The chiral complex from the given options is **PtCl2(en)2 in the cis configuration**.