Is there a difference between meso compounds and identical compounds?
1 Answer
Meso relates to pairs of isomers that are non-chiral (despite possibly having chiral centres) and optically inactive.
Explanation:
Meso compounds contain one or more chiral centres, but they also have a plane of symmetry that bisects the molecule so that each side of the plane is a super imposable mirror image. This symmetry means that there is no optical activity in the molecule (even if the chiral centre/s are present).
In order to be optically active the two isomers should form non-superimposable mirror images.
Meso compounds are therefore non-chiral and optically inactive.
"Meso" comes from the Greek for "middle" (relating to the presence of the plane of symmetry that divides the structure down the middle). It is not specifically a synonym for "identical".
