Achiral
Paired Concept:
Chiral
Definition: A molecule or object that is superimposable on its mirror image.
Context: Achirality implies the absence of optical activity and stereochemical differentiation. Such molecules do not exhibit enantiomeric forms.
Example: Methane, Dichloromethane (lack stereogenic center), Meso-tartaric acid is achiral despite having two stereocenters.
Related Terms: Chiral; Symmetry; Plane of symmetry; Meso-compound.
Reference: IUPAC. Compendium of Chemical Terminology (IUPAC Gold Book), 2nd Edition, 1997 (updated 2019).
