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What are Enantiomers?

by Team Goseeko

Enantiomers are a pair of molecules that exist in two forms that are mirror images of one another but cannot be superimposed one upon the other. Enantiomers are in every other respect chemically identical.


The Enantiomers are in every other respect chemically identical.

A pair of enantiomers are distinguishable by the direction in which when dissolved in solution they rotate polarized light, either dextro (d or +) or levo (l or -) rotatory; hence the term optical isomers.

When two enantiomers are present in equal proportions they are collectively refer to as a racemic mixture a mixture.

they do not rotate polarized light because the optical activity of each enantiomer is cancelled by the other enantiomer.

The Enantiomers were introduced as stereoisomers that are non-superimposable mirror images of one another.

Any molecule that is not superimposable on its mirror image and so exists as a pair of enantiomers chiral and to exhibit chirality.

Conversely, any molecule that is superimposable on its mirror image is achiral.

Indeed, whenever a molecule contains a single atom which is tetrahedrally bound to four different substituents, then two enantiomers are possible.

It is however important that the four substituents are different to one another as if any two of them are identical then the structure would become superimposable on its mirror image and so achiral.

The atom connected to four different atoms and is best referred to as a stereogenic centre or simply a stereocenter.

A widely used although somewhat misleading alternative name for a stereocenter is a localized around the central atom, whereas chirality is a property of the molecule as a whole that cannot be localized around one atom or a group of atoms.

The presence of a stereocenter is not a requirement for a molecule to exhibit chirality; it is the most common cause of chirality.

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