Enantioomeereillä

Enantioomeereillä, also known as enantiomers, are a pair of stereoisomers that are non-superimposable mirror images of each other. This means that if you were to hold one enantiomer up to a mirror, the reflection would look exactly like the other enantiomer, but you would not be able to perfectly align them by rotating or flipping them. This property is often described using the analogy of left and right hands. Your left hand is a mirror image of your right hand, but you cannot place your left hand perfectly on top of your right hand so that all parts match.

The term "enantiomer" comes from the Greek words "enantio" meaning "opposite" and "meros" meaning "part". They are a specific type of stereoisomer, which are molecules that have the same molecular formula and connectivity but differ in the spatial arrangement of their atoms. Chirality is the property of a molecule or ion to exist in one of two forms that are mirror images of each other. Molecules that have this property are called chiral, and molecules that do not are called achiral. A common source of chirality in organic molecules is a chiral center, which is typically a carbon atom bonded to four different atoms or groups.

Enantiomers have identical physical properties such as melting point, boiling point, density, and solubility in achiral solvents. However, they differ in their interaction with plane-polarized light. One enantiomer will rotate the plane of polarized light in one direction (dextrorotatory, denoted by + or d), while the other enantiomer will rotate it by the same magnitude in the opposite direction (levorotatory, denoted by - or l). This optical activity is a defining characteristic of enantiomers. Furthermore, enantiomers can exhibit different biological activities. Because biological systems, such as enzymes and receptors, are often chiral themselves, they can interact differently with each of the two enantiomers of a chiral molecule. This can lead to one enantiomer being pharmacologically active while the other is inactive or even toxic.