First of all, re-cap that isomerism can be broadly classified into 2 types:
- Constitutional isomerism, in which atoms are linked together in different ways
- Stereoisomerism, in which atoms have the same connectivity but different arrangements in space.
Today, we will be talking about constitutional isomerism.
Constitutional isomers have the same molecular formula but different structural formulae. This simply means that the atoms are linked together in different ways. They are also known as structural isomers.
There are three types of constitutional isomerism:
- Positional Isomerism
- Chain Isomerism
- Functional Group Isomerism
1. Positional Isomerism
Positional isomers are molecules with the same molecular formula and same functional group but differ in the position of the functional group.
Positional isomers are also commonly known as compounds having the same substituents at different positions on the same carbon skeleton.
Positional isomers have similar chemical properties but different physical properties.
Examples of positional isomers:
2. Chain Isomerism
Chain isomers refers to organic compounds with the same molecular formula and same functional group, but different carbon skeleton.
Chain isomers have similar chemical properties but different physical properties.
Examples of chain isomers: