Stability of the hydrogen bond ring

Intermolecular hydrogen bonds make it difficult to purify phenolic compounds from mixtures, because of the interactions between different molecules, including the solvent. 

Hydrogen bond formation in phenolic compounds can be summarized with the following general rules  

Unless they are sterically hindered, all phenolic compounds take part in hydrogen bonding. 

Intramolecular hydrogen bonds are less stable than intermolecular hydrogen bonds. The formation of intramolecular hydrogen bonds diminishes reactivity, whereas the formation of intermolecular hydrogen bonds can complicate purification. 

Phenolic compounds that form intermolecular hydrogen bonds are typically solid at room temperature. 

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