What are compounds that have the same physical and chemical properties but rotate plane-polarized light in opposite directions called?

Compounds that have the same physical and chemical properties but rotate plane-polarized light in opposite directions are called enantiomers. Enantiomers are a specific type of stereoisomer that are non-superimposable mirror images of each other. This means that while they share the same molecular formula and connectivity of atoms, their three-dimensional arrangements are different, leading to distinct optical activities.

The ability of enantiomers to rotate plane-polarized light in opposite directions—one clockwise (dextrorotatory) and the other counterclockwise (levorotatory)—derives from the presence of chiral centers in their molecular structure. A chiral center is typically a carbon atom bonded to four different groups, resulting in two unique configurations or isomers.

In contrast, stereoisomers encompass a broader category that includes both enantiomers and diastereomers, which are not related as mirror images and may have different physical properties. Isomers refer to compounds that have the same molecular formula but differ in the arrangement of atoms, which can be either structural isomers or stereoisomers but do not specifically imply the properties related to optical activity. Achiral compounds, on the other hand, do not have chirality and do not rotate plane