enantiomer: Quick Facts

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Also Known As	enantiomorph • antimer • optical antipode

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Analogy between chemical reactions of enantiomers and a hand grasping a ball. If the ball is featureless, the right and left hands (enantiomers) have exactly the same interactions with the ball. However, if the ball has the word “Label” written on it and is thus a chiral object, that labeled ball will be optically active; it will mimic a single enantiomer. The left and right hands will interact differently with the labeled ball. The little finger of the right hand will approach the capital “L” of “Label” while the thumb will approach the lowercase “l.” For the left hand, the interactions will be just the opposite: the little finger will approach the lowercase “l” and the thumb the capital “L.” The figure shows these interactions, as well as a molecular counterpart in which a pair of enantiomers, (R)- and (S)-bromochlorofluoroiodomethane, interacts with a single enantiomer, (S)-2-chlorobutane. In the R enantiomer, the bromine atom approaches the methyl group (―CH3), and the iodine atom approaches the ethyl group (―CH2CH3). In the S enantiomer, the bromine atom approaches the ethyl group, and the iodine atom approaches the methyl group.

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racemic mixture resolution racemization optical isomerism

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isomerism: Enantiomers