Position Isomerism in Structural Isomerism

Position isomerism is a type of structural isomerism where the isomers differ in the position of the functional group or substituent on the carbon chain. This type of isomerism occurs in compounds with the same molecular formula but different structural arrangements.

Examples of Position Isomers

1. Butene
- But-1-ene has the double bond on the first carbon atom of the chain
- But-2-ene has the double bond on the second carbon atom of the chain

2. Pentanol
- 1-Pentanol has the hydroxyl group on the first carbon atom of the chain
- 2-Pentanol has the hydroxyl group on the second carbon atom of the chain

3. Dichlorobenzene
- 1,2-Dichlorobenzene has the chlorine atoms on adjacent carbon atoms
- 1,3-Dichlorobenzene has the chlorine atoms on carbon atoms that are separated by one carbon atom

Significance of Position Isomerism

Position isomerism plays an important role in the properties and behaviour of compounds. The differences in the position of functional groups or substituents can affect the physical, chemical, and biological properties of a compound. For example, the position isomers of butene have different boiling points and reactivity due to the different locations of the double bond. Similarly, the position isomers of pentanol have different solubility and odour due to the different locations of the hydroxyl group.

Conclusion

Position isomerism is a type of structural isomerism where the isomers differ in the position of the functional group or substituent on the carbon chain. This type of isomerism is important in understanding the properties and behaviour of compounds.

In position isomerism, the position of the group is changed in the group itself. Thus, in position isomerism, there is a change in the structure. So, position isomerism is a part of structure isomerism.