Question

Which of the following is more appropriate reason for aniline being less basic than aliphatic amines?

• A. Inductive effect
• B. Steric hindrance
• C. Positive mesomeric effect
• D. Negative mesomeric effect

Answer 1

Answer: (C)

Positive mesomeric effect

$N{H}_2$ gives e- away from the group.
So e- density of N decrease and hence less available for Protonation.
So less Basicity.
In aliphatic amines, no mesomerism (resonance) takes place. Thus it has more electrons available for donation thus shows more basic property.