Types of Structural Isomerism

The six different types of structural isomers are mentioned below:

1. Chain Isomerism
2. Positional Isomerism
3. Functional Isomerism
4. Metamerism
5. Tautomerism
6. Ring-Chain Isomerism

Let’s learn them one by one in detail along with their examples are discussed below:

Chain Isomerism

The type of structural isomerism in which the two or more compounds have the same type of molecular formula with having difference in the main chains is called as Chain Isomerism. The two forms of chain isomerism are linear and branched isomerism.

Chain isomerism is also called as Skeletal Isomerism.

Example: C₅H₁₂: Pentane, Neo-Pentane, and Iso-Pentane. The structural image is shown below:

Positional Isomerism

The type of structural isomerism in which the position of the functional group is different with respect to the main chain is called as Positional Isomerism.

Example: C₃H₈O: 1-propyl alcohol, and 2-propanol. The structural image is shown below:

Functional Isomerism

The type of structural isomerism in which the compound have different functional groups of same number of atoms is called as Functional Isomerism. This is also called as Functional Group Isomerism.

Example: C3H6O: Propanone and Propanal

Metamerism

The type of structural isomerism in which different alkyl groups on either side of functional groups are present is called as Metamerism.

Example: C₄H₁₀O: Diethyl Ether and Methyl Propyl Ether

Tautomerism

The type of structural isomerism in which two isomers are in a stable dynamic equilibrium is called as Tautomerism. This is a special type of functional isomerism.

Example: C₃H₆O: Ketone and Enol

Ring-Chain Isomerism

The type of structural isomerism in which different chain structures appear to be connected in a ring pattern is called as Ring-Chain Isomerism.

They have two different structures as cyclic, and as open-chain.

Example: C₃H₆: Propene and Cyclopropene

Structural Isomerism is the phenomenon of organic compound having same molecular formula but different structural arrangements. The compounds which shows the property of structural isomerism are called Structural Isomers. There are in total six types of structural isomerism.

In this article, we will learn in detail about structural isomers, structural isomerism, its types and examples in detail. Before getting into Structural Isomerism, let’s understand first What is an Isomer?