Question

Which of the set of compounds do not have conjugated system?

• A. $\left(ii\right),\left(iv\right),\left(v\right)$ and $\left(vi\right)$
• B. $\left(i\right),\left(ii\right),\left(v\right),$ and $\left(vii\right)$
• C. $\left(ii\right),\left(iii\right),\left(v\right)$ and $\left(vi\right).$
• D. None of these

Answer 1

Answer: (A)

$\left(ii\right),\left(iv\right),\left(v\right)$ and $\left(vi\right)$

In a conjugated system, electrons are delocalized with the alternate single and double bond. Lone pairs can also be part of the system.

Compounds $\left(i\right),\left(iii\right)$ and $\left(vii\right)$ have a conjugated system.

Three compounds which do not have a conjugated system are $\left(ii\right),\left(iv\right),\left(v\right)$ and $\left(vi\right)$ .

Hence the correct option is A.