For a Friedel - Craft reaction using `AlCl_3`which compound can be used as solvent, benzene or nitrobenzene ?

Options

A. nitrobenzene but not benzene
B. benzene but not nitrobenzene
C. both benzene and nitrobenzene
D. neither benzene nor nitrobenene

Answer

To determine which compound can be used as a solvent for a Friedel-Crafts reaction using AlCl₃, we need to analyze the properties of the two options: benzene and nitrobenzene.

### Step-by-Step Solution:

1. **Understanding Friedel-Crafts Reaction**:
- Friedel-Crafts reactions are electrophilic aromatic substitution reactions that require a Lewis acid catalyst, such as AlCl₃. The solvent used should not interfere with the reaction.

2. **Analyzing Benzene**:
- Benzene is a non-polar solvent and can participate in electrophilic aromatic substitution reactions.
- It is reactive and can stabilize the carbocation intermediate formed during the reaction.

3. **Analyzing Nitrobenzene**:
- Nitrobenzene contains a nitro group (-NO₂), which is an electron-withdrawing group.
- This electron-withdrawing nature deactivates the aromatic ring towards electrophilic substitution, making it less reactive.
- However, nitrobenzene is a polar solvent and does not participate in the reaction, thus providing a stable medium for the reaction to occur without interfering.

4. **Choosing the Appropriate Solvent**:
- In Friedel-Crafts reactions, it is essential to have a solvent that does not react with the electrophile or the aromatic compound.
- Nitrobenzene, being less reactive due to the presence of the nitro group, is suitable as it does not participate in the reaction but can dissolve the reactants.

5. **Conclusion**:
- Therefore, for a Friedel-Crafts reaction using AlCl₃, nitrobenzene is the appropriate solvent to use, while benzene would not be suitable due to its reactivity.

### Final Answer:
**Nitrobenzene can be used as a solvent for a Friedel-Crafts reaction using AlCl₃.**