Which of the following coordination compounds would exhibit optical isomerism and it is low spin complex

Options

A. `[Cr(en)_(3)]^(+3)`
B. `[Ni(gly)_(3)]^(Theta)`
C. `[Pt(bn)_(2)]^(2o+)`
D. All of these

Answer

To determine which coordination compound exhibits optical isomerism and is a low spin complex, we will analyze the given compounds step-by-step.

### Step 1: Understand Optical Isomerism
Optical isomerism occurs when a compound can exist in two forms that are mirror images of each other (enantiomers). This typically happens in coordination compounds with bidentate ligands that create a chiral environment.

**Hint:** Look for bidentate ligands that can create non-superimposable mirror images.

### Step 2: Identify the Ligands and Their Denticity
- **E-end ligand**: This is a bidentate ligand, which means it can bind to the metal at two sites.
- **Glycine**: This is also a bidentate ligand.
- **Butane-2,3-diamine (Bn)**: This is another bidentate ligand.

**Hint:** Check if the ligand can bind at two different sites to form a chelate ring.

### Step 3: Analyze the Metal Ions
- **Cr³⁺**: This has a configuration of 3d³. It can be a low spin complex depending on the ligand field strength.
- **Ni²⁺**: This has a configuration of 3d⁸. It typically forms high spin complexes with weak field ligands.
- **Pt²⁺**: This has a configuration of 4d⁸ and typically forms square planar complexes, which can be low spin.

**Hint:** Consider the electron configuration and the nature of the ligands (strong or weak field) to determine spin states.

### Step 4: Determine the Spin State
- **Cr³⁺** with strong field ligands can be low spin.
- **Ni²⁺** with bidentate ligands like glycine typically forms high spin complexes.
- **Pt²⁺** with bidentate ligands like Bn can form low spin complexes due to the square planar geometry.

**Hint:** Remember that square planar complexes with d⁸ configuration are usually low spin.

### Step 5: Check for Optical Isomerism
- The **E-end ligand** and **glycine** can potentially create chiral complexes, but the specific geometry needs to be considered.
- The **Bn ligand** with **Pt²⁺** can create a chiral environment, leading to optical isomerism.

**Hint:** Visualize the 3D structure of the complexes to see if they can be non-superimposable.

### Conclusion
The coordination compound that exhibits optical isomerism and is a low spin complex is **[Pt(Bn)₂]²⁺**. This complex is formed with the bidentate ligand butane-2,3-diamine and is square planar, leading to low spin and optical activity.

**Final Answer:** The correct option is **[Pt(Bn)₂]²⁺**.