In which of the following molecules, all atoms are not coplanar ?

Options

A.
B.
C.
D.

Answer

To determine which of the given molecules has atoms that are not coplanar, we will analyze the hybridization of the atoms in each option. Atoms with sp and sp² hybridization are typically coplanar, while atoms with sp³ hybridization are not.

### Step-by-Step Solution:

1. **Analyze Option A**:
- Identify the hybridization of the atoms.
- If there are 3 sigma bonds and 1 pi bond, the hybridization is sp².
- Since all atoms in this structure are sp² hybridized, they are coplanar.

2. **Analyze Option B**:
- This option is a ring structure.
- All the atoms in the ring are sp² hybridized.
- Therefore, all atoms in this molecule are coplanar.

3. **Analyze Option C**:
- This option also presents a ring structure.
- All atoms in the ring are sp² hybridized, indicating they are in the same plane.
- However, there is an additional carbon atom (shown in red) that is sp³ hybridized.
- Since sp³ hybridized atoms are not coplanar, this molecule has atoms that are not in the same plane.

4. **Analyze Option D**:
- This option consists of a ring structure as well.
- All carbon atoms in this structure are sp² hybridized.
- Thus, all atoms are coplanar.

### Conclusion:
The only option where not all atoms are coplanar is **Option C** due to the presence of an sp³ hybridized carbon atom.

### Final Answer:
**Option C** has atoms that are not coplanar.

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