Guide to Stereochemistry Terms
Chiral
A molecule is chiral if it is not superposable on its mirror image.
Achiral
A molecule is achiral if it is superposable on its mirror image.
Meso
A molecule is meso if it is achiral and contains two or more stereocenters.
Enantiomers
Stereoisomers that are non-superposable mirror images.
Diastereomers
Stereoisomers that are non-superposable, but are not mirror images.
Constitutional Isomers
Isomers which contain atoms that differ in connectivity.
Non-isomers
Compounds that do not have the same molecular formula.
Superposable
A term that describes the ability to precisely overlap one object over another. Only identical objects are superposable, everything else is non-superposable.
Stereoisomers
Isomers which have atoms that differ only by their orientation in space. Unlike constitutional isomers, corresponding atoms in stereoisomers exhibit the same connectivity.
Isomers
Compounds that have the same molecular formula.