Optical Isomers is an important class of isomers that have the same molecular structure and molecular formula, but differ in their 3D space orientation. Enantiomers are optical isomers.

Enantiomers, optical isomers that have mirror images that are not superimposable, are called optical isomers. They turn the plane polarized sunlight in the opposite direction.

Optical activity refers to the ability of a chiral mole to rotate the plane-polarized light. Dextrorotary enantiomers rotate the plane polarized in a clockwise manner, while levorotary rotates it in an anticlockwise fashion.

The fundamental reason for an organic molecule’s optical activity is its chirality.

Chiral center: When all four valences are fulfilled by chemically distinct groups, a ‘C’ atom within a molecule is a chiral centre. A carbon should have [katex]{\rm{s}}{{\rm{p}}^{\rm{3}}}[/katex] to act as a chiral centre.

Below are examples of optical isomers and chiral centers.

This C is bonded with four groups A, B, C, and D. Thus, it forms two optical isomers that are mirror images.