diastereomerek

Diastereomers are stereoisomers that are not mirror images of each other. This means that while they have the same molecular formula and the same connectivity of atoms, their three-dimensional arrangements of atoms are different, and they cannot be superimposed on one another by rotation or translation. Diastereomers differ in configuration at one or more, but not all, stereocenters.

In contrast to enantiomers, which are stereoisomers that are non-superimposable mirror images, diastereomers do not possess this mirror-image relationship. This fundamental difference leads to distinct physical and chemical properties for diastereomers. For example, diastereomers will have different melting points, boiling points, solubilities, and spectroscopic properties. They can also react at different rates with chiral reagents, a property exploited in various chemical syntheses.

A common scenario where diastereomers arise is in molecules with multiple chiral centers. If a molecule has two chiral centers, say at positions C2 and C3, a change in configuration at only C2, while C3 remains the same, will result in a pair of diastereomers. If the configuration changes at both C2 and C3, and the resulting molecule is the mirror image of the original, then they are enantiomers. If the resulting molecule is not the mirror image, they are diastereomers. The presence of double bonds that restrict rotation can also lead to diastereoisomers, known as geometric isomers or cis-trans isomers, which are a specific type of diastereomer.