What is the difference between tautomerism and metamerism?

Question

Isabella Acosta · Accepted Answer

Tautomerism and metamerism are different types of structural isomerism.

Structural isomerism is a form of isomerism in which molecules have the same molecular formula but their atoms are connected in different orders.

Structural isomerism is divided into:

• Chain isomerism
• Positional isomerism
• Functional group isomerism
• Tautomerism
• Metamerism

Tautomerism

Tautomerism is a dynamic equilibrium between two compounds with same molecular formula.

The most common form of tautomerism is keto-enol tautomerism.

A carbonyl compound containing at least one α-hydrogen atom is converted to an enol by the transfer of an α-hydrogen onto the oxygen atom. For example,

and #underbrace("CH"_3"-O-CH"_2"CH"_2"CH"_3)_color(red)("methyl propyl ether") #

They both contain the ether functional group, but they have different alkyl groups attached to the oxygen atom.

Sarah Angotti · Answer

undefined Tautomerism involves the migration of a hydrogen atom along with a double bond or migration of an atom or group within a molecule, resulting in structural isomers that interconvert rapidly. Metamerism involves the presence of different alkyl groups on either side of a functional group within a molecule, resulting in structural isomers with different physical and chemical properties.