Enantiomers are a pair of stereoisomers that are non-superimposable mirror images of each other. They have the same molecular formula and the same connectivity of atoms, but they differ in the spatial arrangement of those atoms. The key feature that distinguishes enantiomers is chirality, which refers to the presence of one or more chiral centers in a molecule. A chiral center is typically a carbon atom bonded to four different groups, resulting in two possible configurations R and S .Enantiomers have identical physical and chemical properties in an achiral environment, such as boiling point, melting point, and solubility. However, they exhibit different properties when interacting with other chiral molecules or in a chiral environment. This difference is particularly important in biological systems, where many molecules are chiral, and the interactions between them are often stereospecific.One of the most significant differences between enantiomers is their optical activity. When plane-polarized light passes through a solution containing a single enantiomer, the plane of polarization is rotated either clockwise dextrorotatory, denoted as + or d- or counterclockwise levorotatory, denoted as - or l- . The two enantiomers of a chiral compound will rotate the plane of polarized light by equal amounts but in opposite directions.An example of two enantiomers with differing properties is the pair of enantiomers for the chiral molecule limonene. Limonene is a monoterpene and a major component of the essential oils of citrus fruits. The two enantiomers are:1. + -Limonene dextrorotatory : This enantiomer has a strong smell of oranges and is commonly found in the peels of citrus fruits. It is used as a flavoring agent and in fragrances.2. - -Limonene levorotatory : This enantiomer has a strong smell of lemons and is found in the peels of lemons and other citrus fruits. It is also used as a flavoring agent and in fragrances.Although both enantiomers have similar chemical properties, their distinct odors demonstrate how enantiomers can have different properties when interacting with chiral environments, such as the olfactory receptors in our noses.