stereoizomeru

Stereoisomers are a type of isomer, which are molecules with the same molecular formula but different arrangements of atoms in space. In stereoisomers, the atoms are connected in the same order, but their spatial orientation differs. This difference in three-dimensional arrangement can lead to significant variations in physical and chemical properties, as well as biological activity.

The two main categories of stereoisomers are enantiomers and diastereomers. Enantiomers are stereoisomers that are non-superimposable mirror images of each other. They are often described as "left-handed" and "right-handed" versions of the same molecule. Enantiomers have identical physical properties such as melting point and boiling point, but they can differ in their interaction with other chiral molecules, such as enzymes and receptors in biological systems. This is why one enantiomer of a drug might be therapeutic while the other is inactive or even harmful.

Diastereomers, on the other hand, are stereoisomers that are not mirror images of each other. Molecules can have multiple chiral centers, and when the configurations at some but not all of these centers are inverted relative to each other, the resulting molecules are diastereomers. Diastereomers typically have different physical and chemical properties, unlike enantiomers. Geometric isomers, such as cis-trans isomers in alkenes, are a subclass of diastereomers. Understanding stereoisomerism is crucial in fields like organic chemistry, biochemistry, and pharmacology.