izoméria

Izoméria is a phenomenon in chemistry where molecules have the same molecular formula but different structural arrangements of atoms. These different arrangements lead to compounds with distinct physical and chemical properties, despite having the same number and type of atoms. The term "isomer" comes from the Greek words isos (equal) and meros (part).

There are two main categories of isomerism: structural isomerism and stereoisomerism. Structural isomers, also known as constitutional isomers, differ in the connectivity of their atoms. This means the atoms are bonded together in a different order. For example, n-butane and isobutane are structural isomers, both having the molecular formula C4H10.

Stereoisomers, on the other hand, have the same connectivity of atoms but differ in their spatial arrangement. This means the atoms are bonded in the same order but are oriented differently in three-dimensional space. Stereoisomerism is further divided into enantiomers (non-superimposable mirror images) and diastereomers (stereoisomers that are not mirror images). The presence of isomers can significantly affect a molecule's reactivity, boiling point, melting point, and biological activity. Understanding isomerism is crucial for predicting and explaining the behavior of chemical compounds.