The correct statement regarding the basicity of aryl amines is:
Answer: (A) Aryl amines are generally less basic than alkyl amines because the nitrogen lone-pair electrons are delocalised by interaction with the aromatic ring electron system.. \textbf{Answer:} (a) \textbf{Solution:} In aryl amines (e.g.
- A.Aryl amines are generally less basic than alkyl amines because the nitrogen lone-pair electrons are delocalised by interaction with the aromatic ring electron system.✓
- B.Aryl amines are generally more basic than alkyl amines because the nitrogen lone-pair electrons are not delocalised by interaction with the aromatic ring electron system.
- C.Aryl amines are generally more basic than alkyl amines because of the aryl group.
- D.Aryl amines are generally more basic than alkyl amines because the nitrogen atom in aryl amines is -hybridised.
Correct Answer
(A) Aryl amines are generally less basic than alkyl amines because the nitrogen lone-pair electrons are delocalised by interaction with the aromatic ring electron system.
Solution & Explanation
\textbf{Answer:} (a) \textbf{Solution:} In aryl amines (e.g. aniline) the nitrogen lone pair is in conjugation with the aromatic ring and is delocalised (/resonance into the ring), so it is less available for protonation. In alkyl amines the lone pair is fully localised on nitrogen and is further boosted by the effect of alkyl groups, so it is more available. Therefore aryl amines are less basic than alkyl amines because of lone-pair delocalisation into the ring. Hence (a).