Square planar complexes of the type MABXL (where A, B, X and L are unidentates) show

Options

A. two cis and one trans isomer
B. two trans and one cis isomer
C. two cis and two trans isomers
D. one cis and one trans isomer

Explanation

To solve the question regarding the square planar complexes of the type MABXL, we need to analyze the possible isomers that can be formed with the given unidentate ligands A, B, X, and L. Here’s a step-by-step breakdown of the solution:

### Step 1: Understanding the Structure
- The complex is square planar, meaning the metal (M) is at the center and the ligands (A, B, X, L) are positioned at the corners of a square.
- Each ligand is unidentate, which means each ligand can only attach to the metal at one point.

**Hint:** Visualize the square planar structure to understand the arrangement of ligands around the central metal.

### Step 2: Arranging the Ligands
- In a square planar arrangement, we can place the ligands in different positions.
- We can fix one ligand in a position and then see how the other ligands can be arranged.

**Hint:** Fix one ligand (e.g., A) and explore the arrangements of the other three ligands (B, X, L).

### Step 3: Identifying Possible Isomers
- By fixing one ligand, we can explore the arrangements of the remaining ligands.
- For example, if we fix A at one position, we can have:
1. B opposite A, with L and X in the remaining two positions.
2. L opposite A, with B and X in the remaining two positions.
3. X opposite A, with B and L in the remaining two positions.

**Hint:** Consider the positions of the ligands relative to each other (cis and trans configurations).

### Step 4: Classifying Isomers
- We can classify the isomers based on the positions of the ligands:
- **Cis Isomers:** Ligands that are adjacent to each other.
- **Trans Isomers:** Ligands that are opposite each other.

- In our case, we can see that:
- When L is opposite B, X is adjacent to both A and L (cis).
- When L is opposite X, B is adjacent to both A and L (cis).
- When B is opposite X, A is adjacent to both L and B (trans).

**Hint:** Count the arrangements where ligands are adjacent (cis) and those that are opposite (trans).

### Step 5: Conclusion
- After analyzing the arrangements, we find:
- There are **two cis isomers** (where L and B or L and X are adjacent).
- There is **one trans isomer** (where B and X are opposite).

Thus, the final answer is that the square planar complex MABXL shows **two cis and one trans isomer**.

**Final Answer:** Two cis and one trans isomer are possible.