Which of the following is more basic than aniline? .

Options

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

Answer

To determine which of the given compounds is more basic than aniline, we will analyze the basicity of each compound based on the structure and the effects of substituents on the nitrogen atom's lone pair.

### Step-by-Step Solution:

1. **Identify the Compounds**:
- The compounds we need to analyze are:
1. Diphenylamine
2. Triphenylamine
3. Para-nitroaniline
4. Benzylamine

2. **Draw the Structures**:
- **Diphenylamine**: Contains two phenyl groups attached to the nitrogen.
- **Triphenylamine**: Contains three phenyl groups attached to the nitrogen.
- **Para-nitroaniline**: Contains an amino group (-NH2) and a nitro group (-NO2) at the para position on the benzene ring.
- **Benzylamine**: Contains a benzene ring attached to a -CH2-NH2 group.

3. **Analyze Basicity**:
- Basicity is influenced by the availability of the lone pair on the nitrogen atom for protonation.
- **Diphenylamine**: The lone pair on nitrogen is delocalized into the two phenyl rings, reducing its availability for protonation. Therefore, it is less basic than aniline.
- **Triphenylamine**: The lone pair is delocalized into three phenyl rings, making it even less basic than diphenylamine and aniline.
- **Para-nitroaniline**: The nitro group (-NO2) is a strong electron-withdrawing group that pulls electron density away from the nitrogen's lone pair, significantly decreasing its basicity compared to aniline.
- **Benzylamine**: The lone pair on nitrogen is not involved in resonance with the benzene ring because of the -CH2- group separating them. This makes the lone pair more available for protonation, thus increasing its basicity.

4. **Conclusion**:
- Among the four compounds, benzylamine has the highest basicity because its nitrogen lone pair is not involved in resonance and is readily available for protonation. Therefore, benzylamine is more basic than aniline.

### Final Answer:
**Benzylamine is more basic than aniline.**