Question

Select the compound which is not aromatic?
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Answer 1

Explanation:

The compound represented by the option (B) is not aromatic

Cyclooctatetraene is a non planar molecule hence not aromatic.

Note: For a molecule to be aromatic, it should have planar, cyclic, conjugated system of (4n+2)π electrons.

Rest all are planer and follows Huckle rule. Thus they are aromatic.

In case of option D loan pair of the nitrogen is in conjugation with double bond, on resonance forms one carbocation inside the  5-membered ring with 2 double bonds. Thus forms an aromatic compound.

Hence, option b