Intramolecular hydrogen bonding is not present in :-

Options

A. p-fluoro phenol
B. Chloral hydrate
C. o-nitro phenol
D. o-fluoro phenol

Answer

To determine which compound does not exhibit intramolecular hydrogen bonding, we need to analyze the structures of the given compounds. Intramolecular hydrogen bonding occurs when a hydrogen atom covalently bonded to an electronegative atom (like oxygen or nitrogen) is attracted to another electronegative atom within the same molecule.

### Step-by-Step Solution:

1. **Identify the Compounds**: The compounds given are:
- Para-fluorophenol
- Chloral hydrate
- Ortho-nitrophenol
- Ortho-fluorophenol

2. **Analyze Para-fluorophenol**:
- Structure: A benzene ring with an -OH group and a -F group in para position.
- Analysis: The hydrogen from the -OH can form a hydrogen bond with the fluorine atom. Therefore, **intramolecular hydrogen bonding is present**.

3. **Analyze Chloral Hydrate**:
- Structure: A benzene ring with an -OH group and a carbonyl group (C=O).
- Analysis: The hydrogen from the -OH group can form a hydrogen bond with the oxygen of the carbonyl group. Hence, **intramolecular hydrogen bonding is present**.

4. **Analyze Ortho-nitrophenol**:
- Structure: A benzene ring with an -OH group and a -NO2 group in ortho position.
- Analysis: The hydrogen from the -OH can form a hydrogen bond with the oxygen in the nitro group. Thus, **intramolecular hydrogen bonding is present**.

5. **Analyze Ortho-fluorophenol**:
- Structure: A benzene ring with an -OH group and a -F group in ortho position.
- Analysis: The distance between the -OH hydrogen and the fluorine is short enough to allow for hydrogen bonding. Therefore, **intramolecular hydrogen bonding is present**.

6. **Conclusion**:
- After analyzing all compounds, we find that **intramolecular hydrogen bonding is not present in Ortho-fluorophenol** due to the inability of the hydrogen from the -OH group to effectively bond with the fluorine atom due to steric hindrance and distance.

### Final Answer:
**Intramolecular hydrogen bonding is not present in: Ortho-fluorophenol.**