Geomerical isomerism is not observed in complexes of coordination number 4 of____________geometry .

Answer

To solve the question regarding geometrical isomerism in coordination compounds, we need to analyze the geometries associated with a coordination number of 4.

### Step-by-Step Solution:

**Step 1: Understand Coordination Number 4**
- Coordination number refers to the number of ligand atoms that are bonded to the central metal atom in a coordination complex. For coordination number 4, there are four ligand sites around the central atom.

**Hint 1:** Remember that coordination number indicates how many ligands are attached to the central atom.

**Step 2: Identify Possible Geometries for Coordination Number 4**
- The two common geometries for coordination number 4 are:
1. Tetrahedral
2. Square planar

**Hint 2:** Recall that tetrahedral geometry has a bond angle of approximately 109.5 degrees, while square planar geometry has bond angles of 90 degrees.

**Step 3: Analyze Geometrical Isomerism**
- Geometrical isomerism occurs when ligands can be arranged in different spatial orientations, leading to distinct isomers (e.g., cis and trans).
- In square planar complexes, it is possible to have cis and trans isomers because ligands can be arranged differently in the same plane.
- In tetrahedral complexes, however, all ligand positions are equivalent due to symmetry. Therefore, there are no distinct arrangements that can lead to different isomers.

**Hint 3:** Consider how the arrangement of ligands affects their spatial orientation and whether they can be distinguished as different isomers.

**Step 4: Conclusion**
- Since tetrahedral geometry does not allow for different spatial arrangements of ligands that lead to geometrical isomers, we conclude that geometrical isomerism is not observed in tetrahedral complexes.

**Final Answer:** Geometrical isomerism is not observed in complexes of coordination number 4 of **tetrahedral geometry**.