Question

The compounds pyridine and planar cyclooctatetraene are .................. respectively

• A. aromatic and non-aromatic
• B. aromatic and ant-aromatic
• C. aromatic and aromatic
• D. ant-aromatic and non-aromatic
• E. anti-aromatic and antiaromatic

Answer 1

Answer: (B)

The compounds pyridine and planar cyclooctatetraene are aromatic and anti-aromatic respectively. For a compound to be aromatic, it must be cyclic, planar. It must contain $(4n+2)\pi$ electrons, where $n$ is any whole number.

Antiaromatic compounds are cyclic compounds with a $\pi$ electron system that has higher energy due to the presence of $4n$ delocalised electrons in it.