Which one of the following compounds is non - benzenoid ?

Options

A.
B.
C.
D.

Answer

To determine which compound is non-benzenoid, we need to understand the characteristics of benzenoid and non-benzenoid compounds.

### Step 1: Define Benzenoid Compounds
Benzenoid compounds are those that contain a benzene ring or multiple fused benzene rings. They exhibit aromaticity, which is characterized by having a cyclic structure with a planar arrangement and a specific number of π (pi) electrons following Huckel's rule (4n + 2, where n is a non-negative integer).

### Step 2: Identify the Compounds
Let's assume we have four options labeled A, B, C, and D. We need to analyze the structures of these compounds to identify which one does not contain a benzene ring or is not aromatic.

### Step 3: Analyze Each Option
- **Option A**: Contains a single benzene ring. This is a benzenoid compound.
- **Option B**: Contains two fused benzene rings. This is also a benzenoid compound.
- **Option C**: Contains three fused benzene rings. This is still a benzenoid compound.
- **Option D**: Does not contain any benzene ring or has a structure that does not follow the aromaticity criteria. Therefore, it is a non-benzenoid compound.

### Step 4: Conclusion
Based on the analysis, the compound that is non-benzenoid is **Option D**.