Question

Which of the following can be a conjugate system ?

• A. $\pi$,$\pi$Conjugation
• B. Positive charge,$\pi$Conjugation
• C. Negative charge,$\pi$Conjugation
• D. Lone pair,$\pi$cConjugation

Answer 1

Answer: (A), (B), (C), (D)

Lone pair,$\pi$cConjugation

What do you mean by conjunction or conjugate position?

When can a system can be considered to be in a conjunction?

Alternate position of the molecule having $\pi$ bond, positive charge, negative charge,odd electron or lone pair of electrons are known as conjugative positions.

Note: Compound having at least two conjugate positions is known as conjugated compound.

Type of conjugates

(|) $\pi$,$\pi$conjugation:If all conjugate position have $\pi$ bomds,then conjugation is known as $\pi$,$\pi$conjugation

$C\underset{1}{H_2}=CH-\underset{3}{C}H=C{H}_2$

$C{H}_3-CH-2-\underset{1}{C}H-CH=CH-\underset{5}{C}H=C{H}_2$

All of the above compounds have $\pi$,$\pi$conjugation.

(||) Positive charge ,$\pi$conjugation : In this case all conjugation positions have $\pi$ bonds and only one conjugation position has positive charge. If this is the case,then conjugation is known as positive charge,$\pi$conjugation.