The correct statement regarding the basicity of aryl amines is:
Answer: (A) (A) Aryl amines are generally less basic than alkyl amines because the nitrogen lone-pair electrons are delocalized by interaction with the aromatic ring electron system.. \textbf{Answer:} (A) In aryl amines the N lone pair is delocalized into the aromatic ring, lowering electron availability and hence basicity.
- A.(A) Aryl amines are generally less basic than alkyl amines because the nitrogen lone-pair electrons are delocalized by interaction with the aromatic ring electron system.✓
- B.(B) Aryl amines are generally more basic than alkyl amines because the nitrogen lone-pair electrons are not delocalized by interaction with the aromatic ring electron system.
- C.(C) Aryl amines are generally more basic than alkyl amines because of aryl group.
- D.(D) Aryl amines are generally more basic than alkyl amines, because the nitrogen atom in aryl amines is sp-hybridized.
Correct Answer
(A) (A) Aryl amines are generally less basic than alkyl amines because the nitrogen lone-pair electrons are delocalized by interaction with the aromatic ring electron system.
Solution & Explanation
\textbf{Answer:} (A) In aryl amines the N lone pair is delocalized into the aromatic ring, lowering electron availability and hence basicity. \textbf{Solution:} In an aryl amine such as aniline , the lone pair on nitrogen is in conjugation with the benzene ring and is delocalized over the ortho/para positions (resonance). This reduces the electron density on nitrogen, so it is less available to bind a proton. Consequently aryl amines are weaker bases than alkyl amines like , where the effect of the alkyl group actually increases electron density on N. The nitrogen in aniline is (slightly flattened toward for better overlap), not , so option (D) is wrong. Therefore (A) is correct.