Difference Between Benzene and Phenyl

Main difference

The main difference between benzene and phenyl is that benzene is made up of six hydrogen atoms while phenyl is made up of five hydrogen atoms.

benzene vs. phenyl

Benzene is known as a volatile, liquid, colorless hydrocarbon that exists in petroleum; On the other hand, phenyl is known as a group that is derived from benzene and is usually combined with other molecules. Benzene consists of six hydrogen atoms; in contrast, phenyl consists of five carbon atoms.

The stability of benzene is very high when it is alone and not combined with other molecules; on the other hand, phenyl has low stability when alone. C 6 H 6 is the chemical formula of benzene; on the other hand, C 6 H 5 is the chemical formula that is written for phenyl.

Benzene is considered a functional group that contains a benzene ring that is usually attached to the CH 2 group ; conversely, a phenyl is also a functional group consisting of six C atoms normally bonded in a hexagonal ring in which one C atom is bonded to a substituent and the remaining five C atoms are bonded to hydrogen atoms .

The abbreviation for benzene is “Bn” which is used to represent the benzyl group, just as BnOH is marked for benzyl alcohol; on the other hand, the abbreviation for phenyl is “Ph”, which is used to represent the phenyl group, as PhH is used to donate benzene.

The bond dissociation energy, which is required for the cleavage of the benzyl CH bond, is 90 kcal/mol, while the energy which is required for the cleavage of the phenyl CH bond is 113 kcal/mol. Benzyl is widely used in organic synthesis as a security group for carboxylic acids and alcohols; On the other hand, phenyl-containing compounds are widely used in medicines, such as atorvastatin is used to minimize cholesterol level and fexofenadine is used to cure allergies.

Enhanced reactivity characterized the benzylic positions due to the low bond dissociation energy of the benzylic CH bonds, but the benzylic substitutions show higher reactivity in free radical oxidation, halogenation, hydrogenolysis, etc. energy, phenyl substances are hydrophobic and resist oxidation.

Comparison chart

Benzene Phenyl
The functional group, consisting of a benzene ring that is directly attached to the CH 2 group , is known as benzene. The functional group consists of six C atoms in which one is attached to the substituent and others are attached to the hydrogen atom.
Properties
A colorless, liquid, volatile hydrocarbon that exists in petroleum. A group that is derived from benzene and is usually combined with other molecules.
Number of hydrogen atoms
Consists of six hydrogen atoms Consists of five carbon atoms
Stability
Stability is very high when it is alone and not combined with other molecules. Has little stability when alone
Chemical formula
C6H6 _ _ _ C6H5 _ _ _
Abbreviation
“Bn”, which is used to represent the benzyl group, like BnOH, is marked for benzyl alcohol “Ph” which is used to represent the phenyl group, like PhH is used to donate the benzene
Bond dissociation energy
The bond dissociation energy that is necessary for the separation of the benzyl CH bond is 90 kcal/mol. The energy needed for the dissociation of the phenyl CH bond is 113 kcal/mol
Use
Widely used in organic synthesis as a security group for carboxylic acids and alcohols. Widely used in medicines such as atorvastatin is used to minimize cholesterol level, and fexofenadine is used to cure allergies.
Reactivity
Enhanced reactivity characterized the benzylic positions due to the low bond dissociation energy of the benzylic CH bonds, but the benzylic substitutions show increased reactivity in free radical oxidation, halogenation, hydrogenolysis, etc. The lower reactivity characterized the phenyl positions due to the high bond dissociation energy, phenyl substances are hydrophobic and resist oxidation.
What is benzene?

The property of benzene is that it is a colorless and unstable liquid hydrocarbon found in petroleum. Benzene is considered to be a ring structure and its formula is C 6 H 6 .

The total carbon atoms of benzene are usually joined through single bonds, and these three bonds are discontinuously arranged. One of each carbon atom is bonded to the single hydrogen atom, and thus all six hydrogen atoms are bonded to all six carbon atoms.

Due to the existence of double bonds in benzene, the π-bond electrons joined together to form two electron clouds that are present in the benzene ring, either at the top or the bottom of the ring. The electron cloud is considered to be parallel to the plane of the benzene ring, and this particular structure of the benzene ring was first proposed by Kekule (1872); that is why the structure of benzene is also known as the Kekule structure.

What is phenyl?

Phenyl is a functional group that is a result of benzene and then bonds with the other molecules. The molecular formula of phenyl is C6H5. Phenyl is made up of alternating double bonds, which are the same ones found in benzene.

The reason for the high reactivity of phenyl is that it consists of a vacant site where no hydrogen atom is present. So the phenyl group is attached to other different molecules through the vacant site, which enhances the reactivity of the phenyl.

Normally, the benzyl or phenyl group is considered by some to be the same, but it is not. These two groups are very different from each other due to the presence of the –CH 2 – group in benzene, which is attached to the benzene ring. Phenyl is present in the form of phenol, which is the most common molecule in the phenyl group, and from there, the phenyl group is attached to the –OH group.

The energy needed for the dissociation of the phenyl CH bond is 113 kcal/mol. Some common examples of phenyl are triphenylmethane, chlorobenzene, phenol, etc.

Key differences

  1. Benzene is a compound consisting of all paired electrons, while phenyl is a radical consisting of unpaired electrons.
  2. The molecular formula of benzene is C 6 H 6 ; on the other hand, the molecular formula of phenyl is C 6 H 5 .
  3. Benzene forms precipitation in water, while phenyl is soluble in water and forms heterogeneous mixture.
  4. The abbreviation for benzene is “Bn”, for example; benzyl alcohol is normally designated as BnOH; on the other hand, the abbreviation for phenyl is “Ph”, for example, benzene can be indicated as PhH.
  5. 90 kcal/mol is the bond dissociation energy, which is used to break the benzyl CH bond; conversely, 113 kcal/mol is the bond dissociation energy that is used to dissociate the phenyl CH bond.
  6. Benzene is importantly used in the synthesis of organic compounds, which is a protecting group for carboxylic acids and alcohols. In contrast, phenyl-containing compounds are used medicinally; for example, atorvastatin is used to lower cholesterol level and fexofenadine is used to treat allergies.

Final Thoughts

The above discussion concludes that benzene and phenyl are widely used in the different important compounds, but many precautions must be taken when choosing benzene products. The particular difference present between benzene and phenyl is that benzene consists of six hydrogen atoms while phenyl consists of five hydrogen atoms.

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