Question

Which of the following is more basic than aniline ?

• A. Diphenylamine
• B. Triphenylamine
• C. p-nitroaniline
• D. Benzylamine

Answer 1

The Correct Option is D

To determine which compound is more basic than aniline, we need to understand the factors that influence the basicity of amines. Aniline is an aromatic amine, and its basicity is affected by the resonance stabilization of the lone pair on the nitrogen atom. In aniline, the lone pair of electrons on the nitrogen atom is delocalized due to resonance with the benzene ring, reducing its availability to accept protons and making it less basic.

Let's evaluate each option:

1. Diphenylamine: Similar to aniline, diphenylamine has more benzene rings connected to the nitrogen atom, increasing the delocalization of the lone pair. This delocalization reduces the basicity further compared to aniline.
2. Triphenylamine: With even more phenyl groups attached, triphenylamine experiences even greater delocalization of the nitrogen's lone pair, making it the least basic among the given options.
3. p-Nitroaniline: The nitro group is an electron-withdrawing group, which further reduces the electron density on the nitrogen atom, decreasing the compound's basicity compared to aniline.
4. Benzylamine: Benzylamine has a benzyl group instead of a direct connection to the aromatic ring. The lone pair on the nitrogen atom is not significantly delocalized into the benzene ring, making the electron pair more available to accept protons. As a result, benzylamine is more basic than aniline.

From the above analysis, benzylamine is more basic than aniline due to the absence of resonance effects that reduce the availability of the nitrogen's lone pair to act as a base. The correct answer is therefore Benzylamine.