enantiomorit

Enantiomerism is a type of stereoisomerism in which a molecule and its mirror image are non-superimposable. These two forms are called enantiomers. Enantiomers have the same chemical formula and connectivity of atoms, but differ in their three-dimensional spatial arrangement. This difference in spatial arrangement leads to a crucial property: they rotate plane-polarized light in opposite directions. One enantiomer will rotate light clockwise (dextrorotatory, denoted by d or +), while the other will rotate it counterclockwise (levorotatory, denoted by l or -).

The term "enantiomer" comes from the Greek words "enantio" meaning "opposite" and "meros" meaning "part." A mixture containing equal amounts of both enantiomers is called a racemic mixture. Racemic mixtures are optically inactive because the opposing rotations of the individual enantiomers cancel each other out.

Enantiomerism is a fundamental concept in chemistry, particularly in organic chemistry and biochemistry. Many biologically active molecules, such as amino acids and sugars, exist as enantiomers. Often, only one enantiomer exhibits the desired biological activity, while the other may be inactive or even harmful. For example, thalidomide, a drug prescribed in the 1950s and 1960s, had one enantiomer that was effective as a sedative and anti-nausea agent, while the other enantiomer caused severe birth defects. This highlights the importance of understanding and controlling enantiomeric purity in drug development and synthesis. The separation of enantiomers, a process known as chiral resolution, is therefore a critical step in the production of many pharmaceuticals and fine chemicals.