Identity the aromatic compound from the following.

Options

A.
B.
C.
D.

Answer

To identify the aromatic compound from the given options, we will follow the criteria for aromaticity. The criteria are:

1. The compound must be cyclic.
2. The compound must be planar.
3. The compound must have a conjugated system (alternating single and double bonds).
4. The compound must follow Huckel's rule, which states that it should have \(4n + 2\) π electrons, where \(n\) is a non-negative integer.
5. All atoms in the ring must be sp² hybridized.

Now, let's analyze the given compounds step by step:

### Step 1: Check each compound for cyclic structure
- Identify if the compound is a ring structure. If it is not cyclic, it cannot be aromatic.

### Step 2: Check for planarity
- Determine if the compound can lie flat in a plane. If the compound has bulky groups or is otherwise unable to be planar, it cannot be aromatic.

### Step 3: Check for conjugation
- Look for alternating single and double bonds in the compound. A conjugated system is necessary for aromaticity.

### Step 4: Count the π electrons
- Count the number of π electrons in the compound. For a compound to be aromatic, it must satisfy Huckel's rule, which means it should have \(4n + 2\) π electrons.

### Step 5: Check hybridization
- Ensure that all the atoms in the ring are sp² hybridized. If any atom is sp³ hybridized or has a different hybridization, the compound cannot be aromatic.

### Analysis of Given Compounds:
1. **Compound A**:
- Cyclic: Yes
- Planar: Yes
- Conjugated: Yes
- π Electrons: 6 (satisfies \(4n + 2\) where \(n=1\))
- Hybridization: All sp²
- **Conclusion**: This is an aromatic compound.

2. **Compound B**:
- Cyclic: Yes
- Planar: Yes
- Conjugated: No (only has 4 π electrons)
- π Electrons: 4 (does not satisfy \(4n + 2\))
- **Conclusion**: This is not aromatic.

3. **Compound C**:
- Cyclic: Yes
- Planar: Yes
- Conjugated: Yes
- π Electrons: 4 (does not satisfy \(4n + 2\))
- **Conclusion**: This is not aromatic.

4. **Compound D**:
- Cyclic: Yes
- Planar: Yes
- Conjugated: Yes
- π Electrons: 8 (does not satisfy \(4n + 2\))
- **Conclusion**: This is not aromatic.

### Final Conclusion:
The only aromatic compound among the given options is **Compound A**.