Question

Define metamerism.

Answer 1

Isomerism:

• Isomerism is the phenomenon in which two or more compounds have the same molecular formula but different structural formulas. The compounds showing this phenomenon are known as isomers of each other.
• Isomerism is of different types:

(a) Structural isomerism (b) Stereoisomerism

Structural isomerism:

• Structural isomerism is the isomerism in which two or more compounds have the same molecular formula but different structural formulas.
• There are six types of isomerism.
• Metamerism is one of the types of structural isomerism.

Metamerism:

• It is a type of isomerism in which compounds have the same molecular formula but different alkyl groups on either side of functional groups and are called Metamers.
• Metamers are the isomers having the same molecular formula but different alkyl groups on two sides of functional groups. This phenomenon of isomerism is called metamerism.
• Usually, molecules having divalent oxygen atoms or sulfur atoms show metamerism.

For example:

• Methoxy propane is ${\mathrm{C}}_4{\mathrm{H}}_{10}\mathrm{O}$. Its metamers are as follows:

$$\begin{gathered} {\mathrm{CH}}_3-\mathrm{O}-{\mathrm{CH}}_2-{\mathrm{CH}}_2-{\mathrm{CH}}_3 \\ (1-\mathrm{methoxy}\mathrm{propane}) \end{gathered}$$

$$\begin{gathered} {\mathrm{CH}}_3-{\mathrm{CH}}_2-\mathrm{O}-{\mathrm{CH}}_2-{\mathrm{CH}}_3 \\ (\mathrm{Ethoxy}\mathrm{ethane}) \end{gathered}$$