Difference Between Alkyl and Aryl

Main Difference

The main difference between the alkyl and the aryl is that alkyl is a kind of functional group which contains no aromatic ring, whereas aryl is a kind of functional group which contains an aromatic ring.

Alkyl vs. Aryl

Functional groups are referred to as a part of the organic molecules which show the characteristic properties of a particular molecule. They can be a group of atoms, an atom, or even an ion. Most of the time, these functional groups are responsible for reactions that the molecule may endure. Carboxylic acid groups, alkyl, aryl, alcohols, amine groups, etc are some of the examples for these functional groups.

An alkyl group is basically considered as an alkane that has a vacant point that came into existence because of the loss of a hydrogen atom. An aryl group, on the other hand, always comprises an aromatic ring. It is referred to as a simple aromatic compound that has a ring with one detached hydrogen atom, and this is the reason that allows it to get attached to a carbon chain.

The alkyl groups are considered to be cyclic, branched, or simple, but no aromatic ring is present in this type of functional group. All aryl groups, on the other side, are derived from the benzene structures, and their most common aromatic ring is the benzene.

Sometimes, cycloalkyl groups are confused with the aromatic groups by the people. But a significant difference is present between them. Cycloalkanes have no double bonds and are saturated, but the aromatic rings have double bonds and are unsaturated. Even a significant difference is present in their morphology; the cycloalkanes are considered to have the 3D structures, while, the aromatic compounds are considered to have the planar structures.

Comparison Chart

AlkylAryl
The functional groups which are derived from the alkanes are called as the alkyl groups.The functional groups which are derived from the aromatic rings are called as the aryl groups.
General Formula
The alkyl group is considered to have the general formula CnH2n+1.The aryl groups are considered to have no general formula.
Smallest Group
The smallest alkyl group is the methyl group, which is written as –CH3 and is derived from alkane methane (CH4).The simplest aryl group is phenyl, which has the chemical formula C6H5 and is derived from the benzene.
Structure
The alkyl groups are involved in showing an aliphatic structure.The aryl groups are involved in sowing an aromatic structure.
Morphology
Alkyl groups may have linear, cyclic, or branched morphology.A cyclic morphology is shown by the aryl groups.
Type of Atoms
All the alkyl groups have only hydrogen and carbon atoms in their structure.The aryl groups may have atoms other than the carbon and hydrogen atoms.
Aromatic Rings
No aromatic ring is present in the alkyl group.Aryl groups are composed of the aromatic rings.
Saturation
The alkyl group is referred to as the saturated functional group.Aryl group is referred to as the unsaturated functional group.
Stability
The compounds which contain the alkyl groups are less stable.The compounds which contain the aryl groups are more stable.
Examples
The most common example of the alkyl group is the methyl group, which has been derived from the alkane methane (CH4).Some of the examples of aryl groups include the phenyl group, which has been derived from the benzene and the naphthyl group, which has been derived from the naphthalene.

What is Alkyl?

Alkyl is the functional group that has no aromatic ring. It is a functional group that is present in the organic molecules. The alkyl group is considered to have the general formula CnH2n+1. This group may have linear, cyclic, or branched morphology. All the alkyl groups are considered as the saturated functional group because they are derived from the alkanes. They are considered to have a vacant point that came into existence because of the hydrogen atom that is lost by alkanes. The most common example of the alkyl group is the methyl group, which has been derived from the alkane methane (CH4).

What is Aryl?

Aryl is the functional group which has an aromatic ring. It is basically a simple aromatic compound which has one of its hydrogen atoms missing. Because of this missing hydrogen atom, it becomes able to get attached to a carbon chain. The substitutions may be present in the aromatic structure of these groups. For instance, tolyl is the group which is derived from the toluene. Toluene is the benzene ring which came into existence when a methyl group gets replaced. All of the aryl groups are involved in showing unsaturation. But we cannot consider benzene as the only kind of the aromatic ring that the aryl groups can have.

Key Differences

  1. The functional groups which are derived from the alkanes are called as the alkyl groups, whereas, the functional groups which are derived from the aromatic rings are called as the aryl groups.
  2. The general formula for the alkyl group is given as CnH2n+1, while, there is no general formula for the aryl group.
  3. The smallest alkyl group is the methyl group, which is written as –CH3 and is derived from alkane methane (CH4). Conversely, the simplest aryl group is phenyl, which has the chemical formula C6H5 and is derived from the benzene.
  4. The alkyl group has no aromatic ring; on the other hand, aryl groups are composed of the aromatic rings.
  5. The alkyl groups have the aliphatic structure, and on the flip side, the aryl groups have the aromatic structure.
  6. Alkyl groups may have linear, cyclic, or branched morphology; on the other side, aryl groups have essentially cyclic morphology.
  7. Only hydrogen and carbon atoms are present in the structure of the alkyl groups. Conversely, the aryl groups may have atoms other than the carbon and hydrogen atoms.
  8. Alkyl group is a saturated functional group; on the other hand, the aryl group is an unsaturated functional group.
  9. The compounds which contain the alkyl groups are less stable; on the flip side, the compounds which contain the aryl groups are more stable.
  10. The most common example of the alkyl group is methyl group which has been derived from the alkane methane (CH4), whereas, some of the examples of aryl groups include the phenyl group, which has been derived from the benzene and the naphthyl group which has been derived from the naphthalene.

Conclusion

The above discussion concludes that both the alkyl groups and the aryl groups are referred to as the examples of the functional groups. The former has no aromatic ring and is derived from the alkanes, whereas, the latter contains an aromatic ring and is derived from it.

Harlon Moss

Harlon currently works as a quality moderator and content writer for Difference Wiki. He graduated from the University of California in 2010 with a degree in Computer Science. Follow him on Twitter @HarlonMoss

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