Stereoisomeeri

Stereoisomeeri is a term used in chemistry to describe molecules that have the same molecular formula and the same connectivity of atoms, but differ in their spatial arrangement of atoms. These different spatial arrangements are called stereoisomers. Stereoisomers are a type of isomer, which are chemical compounds that have the same number of atoms of each element but differ in their arrangement.

The primary distinction within stereoisomers is between enantiomers and diastereomers. Enantiomers are stereoisomers that are non-superimposable mirror images of each other, much like your left and right hands. Diastereomers, on the other hand, are stereoisomers that are not mirror images of each other. Cis-trans isomers, also known as geometric isomers, are a specific type of diastereomer where the difference in spatial arrangement arises from restricted rotation around a bond, typically a double bond or within a ring structure.

The presence of stereoisomerism is often due to the existence of chiral centers within a molecule. A chiral center is typically a carbon atom bonded to four different groups. The specific three-dimensional arrangement of these groups around the chiral center dictates the stereochemistry of the molecule. Understanding stereoisomerism is crucial in fields such as organic chemistry, biochemistry, and pharmacology, as different stereoisomers can exhibit vastly different physical, chemical, and biological properties. For instance, one enantiomer of a drug might be therapeutic, while its mirror image could be inactive or even toxic.