In other words, carbon-oxygen bond in phenols has some double bond character while in alcohols it is a pure single bond. Therefore, OH group in phenols is more strongly held as compared to OH group in alcohols

Comparison of OH Group in Phenol vs. Alcohol
The strength of the O-H bond in phenols compared to alcohols can be attributed to several key factors:

1. Resonance Stabilization
- In phenols, the hydroxyl (-OH) group is directly attached to a benzene ring.
- The aromatic system allows for resonance, where the lone pair of electrons on the oxygen can delocalize into the benzene ring.
- This delocalization stabilizes the phenolic structure, making the O-H bond stronger.

2. Inductive Effect
- The presence of the electronegative oxygen atom in the -OH group exerts an inductive effect on the carbon framework.
- In alcohols, the -OH group is attached to a saturated carbon, which does not provide the same resonance stabilization as in phenols.
- The electron-withdrawing nature of the aromatic ring enhances the bond strength in phenols by reducing electron density around the O-H bond.

3. Steric Hindrance
- Alcohols can sometimes experience steric hindrance due to bulky alkyl groups, which may lead to weaker O-H bonds.
- Phenols, having a planar aromatic structure, experience less steric hindrance, allowing for a more effective overlap of orbitals.

4. Acidic Nature
- Phenols are more acidic than alcohols, indicating that the O-H bond in phenols is weaker in terms of bond dissociation energy but more stabilized by resonance, leading to a stronger interaction.
- The ability of phenol to donate a proton more readily than alcohols signifies a stronger bond due to stabilization factors.
In conclusion, the resonance stabilization, inductive effects, and steric factors contribute to the stronger holding of the -OH group in phenols compared to alcohols, making phenols unique in their chemical behavior.