2. Prepared by
• Muhammad Othman
• Muhammad Ahmad
• Muhammad Bahman
• Muhammad Mustafa
Supervisor by
Mr.Akam
3. • Phenolic compounds: are a class of chemical compounds
consisting of a hydroxyl group (—OH) bonded directly to
an aromatic hydrocarbon group
• Phenol
• the simplest of the phenols.
• Phenolic compounds are the substance containing benzoic molecules
With one or several hydroxylic groups.
If molecule contains two or more hydroxylic groups there is polyphenol
Phenols occur either as
colourles liquids or white solids at
room temperature and may be highly
toxic and caustic
6. Coumarin:
is a colorless crystalline solid with a sweet odor
resembling the scent of vanilla and a bitter taste.
It is found in many plants, where it may serve as a
chemical defense against predators.
Lignin:
is one of the components of the plant cell wall,
and has the effect of connecting the cells like
glue that holds cellulose together and present
in all wood
7. flavonoids :
are the most common group of polyphenolic compounds in the
human diet and are found ubiquitously in fruits, vegetables, nuts
and plant-derived beverages, such as tea and wine.
8. Tannins:
are defined as water-soluble phenolic compounds with
molecular weights ranging from 500 to 3000 that have
the property of combining with proteins, cellulose,
gelatin, and pectin to form an insoluble complex.
Tannins are usually divided into classes; those can
hydrolyze (react with water) and the other does not
hydrolyze.
• Example: tea leaves contain Tannin which is a natural
phenolic compound formed from glucose and gallic acid.
9. • Physical properties
The simplest phenols are liquids or low-melting solids
because of hydrogen bonding, they have quite high boiling points
Phenols are similar to alcohols but form stronger hydrogen bonds. Thus,
they are more soluble in water than are alcohols
most of the phenols are essentially insoluble in water
Acidity: Carboxylic acid > Phenol > Water > Alcohol
the intermolecular hydrogen bonding reduces water solubility
And increase volatility
o-nitrophenol is steam
distillable(volatile) while the
isomeric p-nitrophenol is not.
10. Deference between Alcohol and Phenol
ALCOHOL PHENOL
• OH group are attached to alkyl group OH group are attached to aryl group
• general formula OH-R general formula C6H5OH
• Does not have resonance structure does have resonance structure
• Aliphatic compound aromatic compound
• Density of alcohols 789kg/m3 density of phenol 1.07g/cm3
• Alcohols are neutral phenols are acidic
