Enantiomer vs. Diastereomer — What's the Difference?

In chemistry, an enantiomer ( ə-NAN-tee-ə-mər; from Greek ἐνάντιος (enántios) 'opposite', and μέρος (méros) 'part') (also named optical isomer, antipode, or optical antipode) is one of two stereoisomers that are mirror images of each other that are non-superposable (not identical), much as one's left and right hands are mirror images of each other that cannot appear identical simply by reorientation. A single chiral atom or similar structural feature in a compound causes that compound to have two possible structures which are non-superposable, each a mirror image of the other.

Diastereomers (sometimes called diastereoisomers) are a type of a stereoisomer. Diastereomers are defined as non-mirror image non-identical stereoisomers.

Either of a pair of molecules that are mirror images but cannot be superimposed on each other, and that rotate the plane of polarized light by an equal amount in opposite directions. Also called enantiomorph, optical isomer.

(chemistry) diastereoisomer

(chemistry) One of a pair of stereoisomers that is the mirror image of the other, but may not be superimposed on this other stereoisomer. Almost always, a pair of enantiomers contain at least one chiral center, and a sample of either enantiomer will be optically active.

Either of a pair of optical isomers of a chemical substance whose molecules are mirror images of each other, i. e., are related to each other as a right-handed to a left-handed glove; - meaningful only for structures which have internal asymmetry.

Either one of a pair of compounds (crystals or molecules) that are mirror images on each other but are not identical