izomérie

Isomerism is a phenomenon in chemistry where molecules with the same molecular formula have different structural arrangements of atoms. These different arrangements lead to distinct physical and chemical properties. Isomers are compounds that are isomers of each other.

There are two main types of isomerism: structural isomerism and stereoisomerism. Structural isomerism, also known as constitutional isomerism, occurs when the atoms are connected in a different order. This can include chain isomerism, positional isomerism, and functional group isomerism. For example, butanol and diethyl ether both have the molecular formula C2H6O, but their atoms are connected differently.

Stereoisomerism involves molecules with the same connectivity but different spatial arrangements of atoms. This category is further divided into enantiomers and diastereomers. Enantiomers are non-superimposable mirror images of each other, much like left and right hands. Diastereomers are stereoisomers that are not enantiomers, meaning they are not mirror images. Geometric isomerism (cis-trans isomerism) is a type of diastereomerism found in molecules with restricted rotation, such as double bonds.

The study of isomerism is crucial in understanding the behavior of chemical substances, particularly in organic chemistry, where the complexity of molecular structures leads to a vast number of possible isomers. This has significant implications in fields like pharmaceuticals, where different isomers can have vastly different biological activities.