Question

What is metamerism? Explain metamerism with suitable examples of ethers.

Answer 1

Hint:Isomerism is a phenomenon in which the molecules have the same molecular formulae but differ only in their structures.
Metamerism is one of the classifications of structural isomerism.

Complete step-by-step answer:In the question, it is asked to comment on metamerism with a suitable example. Before discussing metamerism we should discuss the basics of isomerism. We are familiar with the term isomerism and its classification, still let's brush up our memory and briefly discuss the concept.
So isomerism is the phenomenon in which the compounds will have the same molecular formulae but will differ from each other by their arrangement or say in their structure.
The structures that have the same molecular formulae with different structures are called isomers.
The main two classifications of isomerism are structural or constitutional isomerism and stereoisomerism.
Structural isomerism- It is the classification of isomerism in which the molecular formulae of the compounds are the same but they differ in their core structure.
The different types of structural isomers are position isomers, chain isomers, functional isomers, metamers, etc.
Stereoisomerism: These are isomers that have the same molecular formulae but differ in the arrangement of atoms and molecules in space.
Metamers are structural isomers in which the molecules will have the same molecular formulae and the functional group present in the compounds will also be the same but they differ in the structure i.e. they differ in the type of alkyl chain attached to two sides of the functional group.
For better understanding let's take an example. Consider the case of ethers, diethyl ether, and methyl propyl ether.
Diethyl ether: $C{{H}_{3}}-C{{H}_{2}}-O-C{{H}_{2}}-C{{H}_{3}}$
Methyl propyl ether:$C{{H}_{3}}-O-C{{H}_{2}}-C{{H}_{2}}-C{{H}_{3}}$
Here both the compounds have the same molecular formulae,${{C}_{4}}{{H}_{10}}O$, but in diethyl ether, two ethyl groups are present on both sides of the ether functional group. And in the methyl propyl ether methyl group and propyl group, two different alkyl chains are present.
These two compounds are the example for metamers.

Note:The primary, secondary and tertiary structures of a compound will come under the classification of structural isomerism, specifically in metamers.
For example, the primary, secondary and tertiary structures of amines, like propyl amine, methyl ethyl amine, trimethyl amines are metamers.