stéréogenic
Stéréogenic refers to a property of an atom or molecule that leads to stereoisomerism, meaning the existence of different spatial arrangements of atoms or groups that are not superimposable on their mirror images. The most common example of a stéréogenic center is a chiral carbon atom. A chiral carbon atom is typically bonded to four different atoms or groups. When such a center exists, the molecule can exist as a pair of enantiomers, which are non-superimposable mirror images of each other. The presence of a stéréogenic center is crucial in many areas of chemistry, particularly organic chemistry and stereochemistry. It dictates the three-dimensional shape of molecules and influences their physical and chemical properties, including their biological activity. For instance, many drugs are chiral, and their different enantiomers can have vastly different therapeutic effects or side effects. Molecules can possess more than one stéréogenic center, leading to a greater number of possible stereoisomers, including diastereomers which are stereoisomers that are not mirror images of each other. The concept of stéréogenic centers is fundamental to understanding molecular structure and reactivity.