What is a meso compound?

A meso compound is a stereoisomer that possess an internal plane of symmetry. This symmetry causes the compound to have identical stereoisomers that cancel each other out, resulting in a non-chiral molecule. This means that it does not exhibit optical activity and cannot rotate plane-polarized light. Meso compounds contain at least two stereocenters which are non-superimposable mirror images that cancel each other out. One of the easiest ways to identify a meso compound is to look for an achiral stereoisomer with an internal plane of symmetry that separates the molecule into two identical halves. Meso compounds are used in many branches of chemistry and have important applications in organic synthesis, biochemistry, and medicinal chemistry.